4,605 results on '"MICELLAR electrokinetic chromatography"'
Search Results
2. Multi-criteria decision analysis: technique for order of preference by similarity to ideal solution for selecting greener analytical method in the determination of mifepristone in environmental water samples.
- Author
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Makwakwa, Tlou A., Moema, Dineo E., and Msagati, Titus A. M.
- Subjects
MULTIPLE criteria decision making ,DECISION making ,VEGETATION greenness ,LIQUID chromatography-mass spectrometry ,MICELLAR electrokinetic chromatography ,WATER sampling - Abstract
This work proposes the use of multi-criteria decision analysis (MCDA) to select a more environmentally friendly analytical procedure. TOPSIS, which stands for Technique for Order of Preference by Similarity to Ideal Solution, is an example of a MCDA method that may be used to rank or select best alternative based on various criteria. Thirteen analytical procedures were used in this study as TOPSIS input choices for mifepristone determination in water samples. The input data, which consisted of these choices, was described using assessment criteria based on 12 principles of green analytical chemistry (GAC). Based on the objective mean weighting (MW), the weights for each criterion were assigned equally. The most preferred analytical method according to the ranking was solid phase extraction with micellar electrokinetic chromatography (SPE-MEKC), while solid phase extraction combined with ultra-high performance liquid chromatography tandem mass spectrometry (SPE-UHPLC-MS/MS) was ranked last. TOPSIS ranking results were also compared to the green metrics NEMI, Eco-Scale, GAPI, AGREE, and AGREEprep that were used to assess the greenness of thirteen analytical methods for mifepristone determination. The results demonstrated that only the AGREE metric tool correlated with TOPSIS; however, there was no correlation with other metric tools. The analysis results suggest that TOPSIS is a very useful tool for ranking or selecting the analytical procedure in terms of its greenness and that it can be easily integrated with other green metrics tools for method greenness assessment. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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- View/download PDF
3. NUTRITIONAL STATUS AND CONSUMPTION OF ENERGY DRINKS AMONG GYM GOERS AND NON-GYM-GOERS IN LUANDA, ANGOLA.
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Chavito Massanga, Lúcia de Fátima and Stela Santana, Marli
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ENERGY drinks ,NUTRITIONAL status ,MICELLAR electrokinetic chromatography ,NUTRITIONAL assessment ,YOUNG adults - Abstract
This article explores the relationship between nutritional status and the consumption of energy drinks among individuals attending gyms and those who do not in Luanda, Angola. The study included 204 male participants, with equal numbers in each group. The findings revealed that coffee and a national energy drink were the most commonly consumed beverages, and there was a significant association between body mass index (BMI) and age in both groups. Additionally, there was a significant association between BMI and the timing of energy drink consumption among gym-goers. The study suggests that these factors may impact individuals' nutritional patterns. The majority of participants were young adults, and most were in the eutrophic nutritional status. Both groups consumed energy drinks, with coffee being the most popular choice. The nutritional composition of the drinks analyzed met recommended standards, and participants had been consuming them for over a year. However, there was a lack of knowledge regarding the beneficial and harmful effects of energy drinks. Gym-goers demonstrated greater knowledge about these effects compared to non-gym-goers. While some participants reported experiencing side effects such as insomnia, tachycardia, nausea, and dizziness, most did not experience any adverse effects. The study also emphasized the need for further research on energy drink consumption in African countries due to limited available information. [Extracted from the article]
- Published
- 2024
4. Rapid indirect separation of glutamine enantiomers by micellar electrokinetic chromatography. Analysis of dietary supplements.
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Salido‐Fortuna, Sandra, Ruano‐Culebras, Paloma, Marina, María Luisa, and Castro‐Puyana, María
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MICELLAR electrokinetic chromatography , *DIETARY supplements , *GLUTAMINE synthetase , *GLUTAMINE , *ENANTIOMERS , *QUALITY control - Abstract
Glutamine is the most abundant free proteinogenic α‐amino acid. It is naturally produced in the organism and acts as a precursor for the synthesis of different biologically important molecules (such as proteins or nucleotides). However, under stressful conditions, the organism is unable to produce it in enough amounts to function properly. Thus, glutamine (Gln)‐based supplements have become increasingly popular over the last decade. Since legal regulations establish that amino acid‐based dietary supplements must contain only the L‐enantiomer and not the racemate, adequate chiral methodologies are required to achieve their quality control. In this work, an analytical methodology based on the use of micellar electrokinetic chromatography is proposed for the rapid enantiomeric determination of DL‐Gln in dietary supplements. Using (+)‐1‐(9‐fluorenyl)‐ethyl chloroformate as a derivatizing agent and ammonium perfluorooctanoate as separation medium, the Gln diastereoisomers formed under optimal conditions were separated in 8 min with a resolution of 2.8. The analytical characteristics of the method were evaluated in terms of linearity, precision, accuracy, and limits of detection/quantitation, and they were found appropriate for the analysis of L‐Gln‐based dietary supplements. [ABSTRACT FROM AUTHOR]
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- 2024
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5. Comparison of aqueous and non-aqueous capillary electrophoresis for the determination of four benzalkonium chloride homologues in compound chemical disinfectants
- Author
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Kai Yao, Ruoke Jiang, Ping Wang, Jing Zhang, Bing Shao, and Xiaojing Ding
- Subjects
Benzalkonium chloride ,Compound chemical disinfectants ,Non-aqueous capillary electrophoresis ,Micellar electrokinetic chromatography ,Ultraviolet detection ,Science (General) ,Q1-390 ,Social sciences (General) ,H1-99 - Abstract
A new method was established for the simultaneous analysis of four homologous benzalkonium chlorides (dodecyldimethylbenzyl ammonium chloride, tetradecyldimethylbenzyl ammonium chloride, hexadecyldimethylbenzyl ammonium chloride, and octadecyldimethylbenzyl ammonium chloride) in compound chemical disinfectants using non-aqueous capillary electrophoresis (CE) based on a micellar electrokinetic chromatography mode with direct ultraviolet detection. The separation was performed on an uncoated fused quartz capillary with a total length of 60.2 cm and a diameter of 25 μm. The separation buffer consisted of a mixture of methanol/acetonitrile (60:40, v/v) containing 70 mmol/L sodium acetate, 60 mmol/L trifluoroacetic acid and 20 mmol/L sodium dodecyl sulfate. The sample buffer was a methanol solution containing only 2 mmol/L trifluoroacetic acid. The separation voltage was set at 8 kV with a working current of approximately 2.3 μA. The detection wavelength was 214 nm. Under optimal conditions, the limit of detection and limit of quantification for these four benzalkonium chlorides (BACs) were 1.0 mg/L and 5.0 mg/L, respectively. Good linearities were observed in the concentration ranges from 5.0 to 100.0 mg/L, with correlation coefficients above 0.999 for all compounds. The recoveries of these four BACs ranged from 92.5 % to 109.1 % with relative standard deviations below 4.7 %. With the new method, all four BACs could be analyzed in a single injection. In contrast, the aqueous CE method in the National Standard GB/T 26369-2020 only allowed for the simultaneous analysis of the first three homologous. The new method demonstrated the improved peak shape compared to the aqueous CE method and then was successfully applied to the analysis of 19 commercially available samples, such as object table disinfectants, hand sanitizers, and disinfectant wipes, which claimed to contain quaternary ammonium compound. The results obtained using the new method were compared with those of the aqueous CE of the National Standard Method, and no statistically significant differences were observed. The new method is simple in pre-treatment and provides accurate results, making it highly suitable for routine analysis.
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- 2024
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6. Development of a sustainable multianalyte MEKC method for quantitation of the antihyperlipidemic drugs ezetimibe together with three statins. Greenness and whiteness appraisal studies.
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Elbordiny, Haydi S., Elonsy, Sohila M., Daabees, Hoda G., and Belal, Tarek S.
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SIMVASTATIN , *SUSTAINABLE development , *MICELLAR electrokinetic chromatography , *EZETIMIBE , *SODIUM dodecyl sulfate , *FUSED silica , *MICELLAR liquid chromatography - Abstract
Implementing powerful and sustainable research that complies with green analytical chemistry (GAC) and white analytical chemistry (WAC) fundamentals can downsize the environmental compliance costs and fruitfully affects practical and economic issues. Within this framework, rapid and white analytical micellar electrokinetic capillary chromatography (MEKC) methodology was developed for the synchronized estimation of the antihyperlipidemic drugs Ezetimibe (EZE), Atorvastatin (ATO), Rosuvastatin (ROS) and Simvastatin (SIM). The technique was established using fused silica capillary (50 cm, 50 µm id) and the background electrolyte was 0.025 M borate buffer pH 9.2 containing 0.025 M sodium dodecyl sulfate (SDS) and 10% v/v acetonitrile as the organic modifier. Diode array detector was adjusted at 243 nm for ATO and ROS and 237 nm for EZE and SIM. Separation was accomplished within 10 min with migration times of 4.12, 5.42, 8.23 and 8.74 min for ROS, ATO, EZE and SIM respectively. The 4 drugs were quantitated in the concentration range of 10–100 μg/mL and the correlation coefficients were not less than 0.9993. The high sensitivity was illustrated by values of the detection and quantitation limits. The limits of detection for ROS, ATO, EZE and SIM were 0.52, 0.75, 0.42 and 0.64 μg/mL, respectively, whereas, the limits of quantitation values were 1.73, 2.50, 1.40 and 2.13 μg/mL for the studied drugs, respectively. In addition to validation, as reported by the ICH guidelines, greenness and whiteness assessment using the novel AGREE calculator and the holistic functionality model RGB12 were performed. The results proved the efficiency and whiteness of the suggested technique to be routinely implemented in quality control laboratories for the assay of the four drugs and the binary mixtures of EZE with either ATO, ROS or SIM in fixed-dose combined tablets. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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- View/download PDF
7. Determination of ticagrelol in rat plasma and tablets by micellar electrokinetic chromatography coupled with large volume sample stacking: Application to a pharmacokinetic study.
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Zayed, Sahar and Belal, Fathalla
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MICELLAR electrokinetic chromatography , *MICELLAR liquid chromatography , *PHARMACOKINETICS , *FUSED silica , *RATS - Abstract
A method using micellar electrokinetic chromatography coupled with large‐volume sample stacking for the determination of ticagrelol was developed and validated. The analysis was performed in a fused silica capillary (41.5 cm effective length, 50 μm diameter) with ultraviolet detection at 195 nm. The background electrolytes were 30 mM phosphate buffer of pH 3.0 with 120 mM sodium dodecylsulfate and 10 % (v/v) acetonitrile (120 s X 50 mbar; 20°C; ‐18 kV) and 30 mM borate buffer of pH 8.5 with 75 mM sodium dodecylsulfate (120 s X 50 mbar; 20°C; 25 kV); under acidic and alkaline conditions, respectively. The method was found to be reliable with respect to specificity, linearity of the calibration line (R2 > 0.99), repeatability (relative standard deviation 2.56%–3.34%), and accuracy (recovery in the range 101.21%–102.67%). The limits of detection and quantitation were 0.032, 0.071, and 0.087, 0.188 μg/mL, respectively. The method was successfully applied for the determination of ticagrelol concentrations in rat plasma and tablets with good recoveries and reproducibility. The presented method proved to be suitable for monitoring ticagrelor in rat plasma. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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8. Simultaneous Enantioseparation of Three Chiral Antifungal Pesticides by Hydroxypropyl-γ-CD-Modified Micellar Electrokinetic Chromatography.
- Author
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Yang, Xiaoyu
- Subjects
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MICELLAR electrokinetic chromatography , *SODIUM dodecyl sulfate , *FENITROTHION , *ANTIFUNGAL agents , *PESTICIDES - Abstract
Simultaneous enantioseparation of three commonly used chiral antifungal pesticides (diniconazole, hexaconazole, and imazalil) was first studied based on micellar electrokinetic chromatography (MEKC) with hydroxypropyl-γ-CD (HP-γ-CD) as chiral selector. In this study, the importance of experimental parameters such as chiral selector type and concentration, sodium dodecyl sulfate (SDS) concentration, the ratio of methanol, and separation voltage in optimizing were investigated. The simultaneous enantioseparation of diniconazole, hexaconazole, and imazalil was successfully achieved in 30 mM borate buffer (pH 9.0) containing 10 mM HP-γ-CD and 20 mM SDS with methanol (8%) added as organic modifiers. The resolution of diniconazole, hexaconazole, and imazalil was 15.2, 2.12, and 2.78, respectively, and the peak efficiency (N) was over 566,825 plates/m. This study provides an alternative way to systematically separate chiral antifungal pesticides with high efficiency. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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9. Green and white MEKC for determination of different anti-diabetic binary mixtures and their triple-combo pill
- Author
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Aya R. Ahmed, Mohamed A. Korany, Shereen M. Galal, and Marwa A. A. Ragab
- Subjects
Empagliflozin ,Greenness and whiteness appraisal ,Linagliptin ,Metformin ,Micellar electrokinetic chromatography ,Chemistry ,QD1-999 - Abstract
Abstract The work introduces green and white sustainable micellar electrokinetic chromatography (MEKC) procedure that could analyze therapeutically related drugs, empagliflozin (EMP), linagliptin (LIN) and metformin (MET) which are antidiabetic drugs with different mechanism of action, in their different pharmaceutical combinations. The method not only comply with the green analytical concepts, but also it is in line with sustainable analytical concepts as it is economic by applying the same operating conditions to analyze different pharmaceuticals in quality control (QC) labs which is a crucial step in QC labs and research centers to save time, effort, and money. Moreover, the method functionality regarding its scope with its achieved levels of accuracy, precision, low detection, and quantitation limits is tested using white assessment tool and compared with reported methods. The proposed MEKC coupled with a diode array detector (DAD) has been developed and validated for micro estimation of EMP and LIN in their low critical concentrations with MET in a ratio of (EMP: MET, 1:40) and (LIN: MET, 1:200). Separation was achieved within 6 min using fused silica capillary (40 cm × 50 µm id) using 20 mM Tris buffer (pH 10) in presence of 50 mM sodium dodecyl sulphate and 10% v/v methanol. The concentration ranges of the studied anti-diabetic drugs were 10–500, 10–100 and 2.5–100 µg. mL−1 for MET, EMP and LIN, respectively. The developed method is the first MEKC for concurrent determination of EMP, LIN and MET with high separation efficiency, low solvent consumption and regard as an easy green and white analytical tool. Moreover, Greenness and whiteness assessment were done via the most widely used Analytical Eco-Scale, the innovative AGREE tool and the RGB 12 algorithm.
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- 2023
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10. Determination of some drugs used against neurodegenerative disorders by micellar electrokinetic chromatography with running buffer containing SDS
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Traczuk Adam, Jaglinska Kamila, and Polak Beata
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separation ,drugs analysis ,micellar electrokinetic chromatography ,sodium dodecyl sulphate ,Medicine - Abstract
In this work, analysis of some drugs used in the treatment of neurodegenerative disorders (sulpiride, olanzapine, carbamazepine, trazodone, clomipramine, and pridinol) was achieved through micellar electrokinetic chromatography (MEKC). The effect of surfactant (sodium dodecylsulphate), acetonitrile, and buffer pH and concentration on the solute retention was also investigated. Successful separation of all compound mixtures was obtained. The method was applied for the quantitative analysis of investigated compounds, and the LOD and LOQ were determined. The LOD values were in the range from 0.0127 mg/mL for clomipramine, to 0.1398 mg/mL for pridinol, while LOQ were in the range 0.0384 mg/mL for clomipramine, to 0.4237 for pridinol. The mode was also applied for the determination of investigated solutes in pharmaceutical prescriptions.
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- 2023
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11. Method Development for Determination of Doripenem in Human Plasma via Capillary Electrophoresis Coupled with Field-Enhanced Sample Stacking and Sweeping.
- Author
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Liang, Hsin-Hua, Lin, Yu-Chao, Hung, Chin-Chuan, Hou, Yu-Chi, and Lin, Yi-Hui
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CAPILLARY electrophoresis , *MICELLAR electrokinetic chromatography , *DRUG monitoring , *FUSED silica , *SOLID phase extraction , *DRUG resistance in bacteria - Abstract
In this study, we established a novel capillary electrophoresis method for monitoring the concentration of doripenem in human plasma. As a time-dependent antibiotic, doripenem maximizes its antibacterial effects and minimizes the potential for antibiotic resistance through careful therapeutic drug monitoring. Two online preconcentration techniques, field-enhanced sample stacking (FESS) and sweeping, were coupled to enhance the detection sensitivity. Briefly, an uncoated fused silica capillary (40 cm × 50 μm i.d) was rinsed with a high conductivity buffer (HCB) composed of 150 mM phosphate buffer (NaH2PO4, pH 2.5) and 20% methanol. A large sample plug prepared in a low-conductivity phosphate buffer (50 mM NaH2PO4, pH 2.5) was then hydrodynamically injected (5 psi, 80 s) into the capillary. Under an applied voltage of −30 kV, the analyte was accumulated at the FESS boundary and swept by the negatively charged micelles toward the UV detector. Plasma samples were pretreated by solid-phase extraction (SPE) to eliminate endogenous interferences. The validation results demonstrated a high coefficient of determination (r2 > 0.9995) for the regression curve with impressive precision and accuracy: relative standard deviation (RSD) <5.86% and relative error <4.63%. The limit of detection (LOD, S/N = 3) for doripenem was determined to be 0.4 μg/mL. Compared to the conventional micellar electrokinetic chromatography method, our developed method achieved a sensitivity enhancement of up to 488-fold for doripenem. Furthermore, the newly developed method successfully quantified doripenem concentrations in plasma samples obtained from patients accepting doripenem regimens, proving its application potential in the clinical realm. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
12. Green versatile micellar electrokinetic chromatographic method for determination of six antimicrobial and anti-inflammatory drugs in combined dosage forms.
- Author
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Elmansi, Heba, El-Awady, Mohamed I., Barghash, Sona, El-Razeq, Sawsan Abd, and Belal, Fathalla
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DOSAGE forms of drugs ,ANTI-infective agents ,ANTI-inflammatory agents ,CROMOLYN sodium ,HYDROCHLOROTHIAZIDE ,CIPROFLOXACIN ,MICELLAR electrokinetic chromatography - Abstract
A fast reliable micellar electrokinetic methodology was investigated for the concurrent quantitation of six antimicrobial and anti-inflammatory drugs, namely, ciprofloxacin, dexamethasone, metronidazole, ornidazole, spiramycin and tinidazole. The method has the merits of rapidity, precision, and sensitivity. The separation was carried out in less than 7 min by applying a basic background electrolyte consisting of 25 mM disodium tetraborate buffer, pH 9 containing 50 mM SDS at 25 kV using photodiode array detector at 230 and 315 nm. The internal standard used during analysis was cromolyn sodium and validation was carried out following ICH guidelines. The proposed method showed linear response over the range from 0.5 to 10.0 μg mL
−1 reaching limits of detection and limits of quantitation in the ranges of 0.09–0.2 μg mL−1 and 0. 27–0.6 respectively. The method's greenness was estimated using the GAPI tool where excellent greenness was concluded. Co-formulated or single-ingredient commercial preparations were investigated and the results were statistically evaluated. [ABSTRACT FROM AUTHOR]- Published
- 2023
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13. Collection of Partition Coefficients in Hexadecyltrimethylammonium Bromide, Sodium Cholate, and Lithium Perfluorooctanesulfonate Micellar Solutions: Experimental Determination and Computational Predictions.
- Author
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Saranjam, Leila, Nedyalkova, Miroslava, Fuguet, Elisabet, Simeonov, Vasil, Mas, Francesc, and Madurga, Sergio
- Subjects
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MICELLAR solutions , *SODIUM cholate , *MICELLAR electrokinetic chromatography , *PARTITION coefficient (Chemistry) , *K-means clustering , *BROMIDES , *SOLVATION , *PROPANOLS - Abstract
This study focuses on determining the partition coefficients (logP) of a diverse set of 63 molecules in three distinct micellar systems: hexadecyltrimethylammonium bromide (HTAB), sodium cholate (SC), and lithium perfluorooctanesulfonate (LPFOS). The experimental log p values were obtained through micellar electrokinetic chromatography (MEKC) experiments, conducted under controlled pH conditions. Then, Quantum Mechanics (QM) and machine learning approaches are proposed for the prediction of the partition coefficients in these three micellar systems. In the applied QM approach, the experimentally obtained partition coefficients were correlated with the calculated values for the case of the 15 solvent mixtures. Using Density Function Theory (DFT) with the B3LYP functional, we calculated the solvation free energies of 63 molecules in these 16 solvents. The combined data from the experimental partition coefficients in the three micellar formulations showed that the 1-propanol/water combination demonstrated the best agreement with the experimental partition coefficients for the SC and HTAB micelles. Moreover, we employed the SVM approach and k-means clustering based on the generation of the chemical descriptor space. The analysis revealed distinct partitioning patterns associated with specific characteristic features within each identified class. These results indicate the utility of the combined techniques when we want an efficient and quicker model for predicting partition coefficients in diverse micelles. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
14. Green and white MEKC for determination of different anti-diabetic binary mixtures and their triple-combo pill.
- Author
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Ahmed, Aya R., Korany, Mohamed A., Galal, Shereen M., and Ragab, Marwa A. A.
- Subjects
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MICELLAR electrokinetic chromatography , *BINARY mixtures , *SODIUM sulfate , *PILLS , *EMPAGLIFLOZIN , *CINNAMON , *LINAGLIPTIN - Abstract
The work introduces green and white sustainable micellar electrokinetic chromatography (MEKC) procedure that could analyze therapeutically related drugs, empagliflozin (EMP), linagliptin (LIN) and metformin (MET) which are antidiabetic drugs with different mechanism of action, in their different pharmaceutical combinations. The method not only comply with the green analytical concepts, but also it is in line with sustainable analytical concepts as it is economic by applying the same operating conditions to analyze different pharmaceuticals in quality control (QC) labs which is a crucial step in QC labs and research centers to save time, effort, and money. Moreover, the method functionality regarding its scope with its achieved levels of accuracy, precision, low detection, and quantitation limits is tested using white assessment tool and compared with reported methods. The proposed MEKC coupled with a diode array detector (DAD) has been developed and validated for micro estimation of EMP and LIN in their low critical concentrations with MET in a ratio of (EMP: MET, 1:40) and (LIN: MET, 1:200). Separation was achieved within 6 min using fused silica capillary (40 cm × 50 µm id) using 20 mM Tris buffer (pH 10) in presence of 50 mM sodium dodecyl sulphate and 10% v/v methanol. The concentration ranges of the studied anti-diabetic drugs were 10–500, 10–100 and 2.5–100 µg. mL−1 for MET, EMP and LIN, respectively. The developed method is the first MEKC for concurrent determination of EMP, LIN and MET with high separation efficiency, low solvent consumption and regard as an easy green and white analytical tool. Moreover, Greenness and whiteness assessment were done via the most widely used Analytical Eco-Scale, the innovative AGREE tool and the RGB 12 algorithm. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
15. Simultaneous Separation and Determination of Nine Active Ingredients in Sanyetangzhiqing by Cyclodextrin-Modified Micellar Electrokinetic Capillary Electrophoresis-Diode Array Detector.
- Author
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Wang, Shanshan, Zhou, Rui, Du, Kunze, Shang, Ye, He, Jun, Li, Jin, Yao, Yaqi, and Chang, Yan-xu
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MICELLAR electrokinetic chromatography , *CHLOROGENIC acid , *ANTILIPEMIC agents , *DETECTORS , *PHENOLIC acids , *QUALITY control - Abstract
A simple and sensitive strategy using cyclodextrin-modified micellar electrokinetic chromatography with diode array detector was developed and applied for the simultaneous separation and determination of nine components in Sanyetangzhiqing (SYTZQ), a hypoglycemic and hypolipidemic agent. Several important parameters affecting separation performance were evaluated and optimized using single variable methods. Under the optimal conditions, baseline separation of the nine components, including four flavonoids (hyperoside, isoquercitrin, quercetin-3-O-glucuronoside, and astragalin), four phenolic acids (chlorogenic acid, rosmarinic acid, salvianolic acid B, and lithospermic acid), and a monoterpenoids (paeoniflorin), were achieved in less than 16 min. The correlation coefficients of the calibration curves were over 0.9996 for all the analytes. Intraday and interday precisions ranged from 0.4% to 4.8% and 1.7% to 5.0%, respectively. Recoveries of analytes varied from 95.3% to 105%. Validation results as well as the application to analyse SYTZQ samples demonstrated the applicability of the proposed method and thus provided an effective tool for the quality control of SYTZQ. Moreover, with the advantages of short time consuming, low energy consumption, high efficiency, and low cost, this method has laid a foundation for the determination and quality evaluation of multicomponents in Chinese herbal compounds. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
16. In‐capillary screening and quantifying the antioxidants of Yangxinshi Tablet using field‐enhanced sample injection‐micellar electrokinetic chromatography.
- Author
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Zhou, Rui, Wang, Lei, Liu, Wenping, Li, Jin, He, Jun, Yao, Yaqi, Yuan, Hongwei, and Chang, Yanxu
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MICELLAR electrokinetic chromatography , *MICELLAR liquid chromatography , *MEDICAL screening , *CAFFEIC acid , *ANTIOXIDANTS , *CHROMATOGRAPHIC analysis - Abstract
An in‐capillary 2,2′‐azinobis‐(3‐ethylbenzthiazoline‐6‐sulphonate) as oxyradicals combining field‐enhanced sample injection with micellar electrokinetic chromatography was developed for screening and determination of the major antioxidants in Yangxinshi Tablet. To obtain simultaneous separation and detection of radicals and analytes, relevant factors were optimized separately. Under the optimum conditions, four compounds including salvianolic acid B, hyperoside, puerarin, and caffeic acid were identified as the major antioxidants. All validation results covering recovery, precision, and stability demonstrated good applicability of the method. On this basis, the total antioxidant activity was successfully evaluated in terms of the decreased peak area of radicals. There was a correlation coefficient of 0.8974 between the total contents of major antioxidants and the total antioxidative activity of the sample. Therefore, these four compounds were selected as combinatorial markers for the quality evaluation of Yangxinshi Tablet. It was concluded that the established method presented a powerful potential to screen and quantify active ingredients in the complex preparation of Chinese medicine. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
17. Analytical Quality by Design-Compliant Development of a Cyclodextrin-Modified Micellar ElectroKinetic Chromatography Method for the Determination of Trimecaine and Its Impurities.
- Author
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Marzullo, Luca, Gotti, Roberto, Orlandini, Serena, Slavíčková, Patricie, Jireš, Jakub, Zapadlo, Michal, Douša, Michal, Nekvapilová, Pavla, Řezanka, Pavel, and Furlanetto, Sandra
- Subjects
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MICELLAR electrokinetic chromatography , *MONTE Carlo method , *RESPONSE surfaces (Statistics) , *CAPILLARY electrophoresis , *SODIUM dodecyl sulfate , *QUALITY control - Abstract
In 2022, the International Council for Harmonisation released draft guidelines Q2(R2) and Q14, intending to specify the development and validation activities that should be carried out during the lifespan of an analytical technique addressed to assess the quality of medicinal products. In the present study, these recommendations were implemented in Capillary Electrophoresis method development for the quality control of a drug product containing trimecaine, by applying Analytical Quality by Design. According to the Analytical Target Profile, the procedure should be able to simultaneously quantify trimecaine and its four impurities, with specified analytical performances. The selected operative mode was Micellar ElectroKinetic Chromatography employing sodium dodecyl sulfate micelles supplemented with dimethyl-β-cyclodextrin, in a phosphate-borate buffer. The Knowledge Space was investigated through a screening matrix encompassing the composition of the background electrolyte and the instrumental settings. The Critical Method Attributes were identified as analysis time, efficiency, and critical resolution values. Response Surface Methodology and Monte Carlo Simulations allowed the definition of the Method Operable Design Region: 21–26 mM phosphate-borate buffer pH 9.50–9.77; 65.0 mM sodium dodecyl sulfate; 0.25–1.29% v/v n-butanol; 21–26 mM dimethyl-β-cyclodextrin; temperature, 22 °C; voltage, 23–29 kV. The method was validated and applied to ampoules drug products. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
18. Capillary Electrophoresis Method for Simultaneous Quantification of Hypocholesterolemic Drugs in Binary Mixture Formulation: Fast, Green, and Cost-Effective Alternative to HPLC.
- Author
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de Souza, Antonio Marcos Callejo, Fajardo, Frank Alonso Gavilano, Rashid, Anas, Tavares, Marina Franco Maggi, and Prado, María Segunda Aurora
- Abstract
A fast and sustainable environment-friendly micellar electrokinetic chromatography coupled with a diode array detector was investigated and validated in accordance with ICH requirements for the simultaneous quantification of ezetimibe and simvastatin in a tablet binary mixture formulation. Drugs' separation from their internal standard and degradation products was achieved using the optimized electrophoretic conditions: 50 µm i.d. × 30 cm fused-silica capillary, background electrolyte composed of 20 mmol L
−1 sodium tetraborate buffer solution (pH 9, adjusted with o-phosphoric acid), 30 mmol L−1 sodium dodecyl sulfate, 12% acetonitrile; with detection at 238 nm and voltage of + 30 kV. Drugs were separated in less than 6 min. The method was linear with determination coefficients 0.9956 and 0.9920 for ezetimibe and simvastatin, respectively; and precise (intra-day 1.05% and 0.38%; inter-day 1.20% and 0.69%) for ezetimibe and simvastatin, respectively. Accuracy was tested through recovery and mean values (101.0 ± 0.77% for ezetimibe and 100.4 ± 0.35% for simvastatin) were obtained. The proposed method is the first that determined ezetimibe and simvastatin in presence of their degradation products. This method can be successfully used in quality control laboratories as an alternative to HPLC technique for the simultaneous quantification of ezetimibe and simvastatin in their combined drug products and could also be used as a stability-indicating method. The proposed method greenness profile was confirmed using Green Analytical Procedure Index and Analytical GREEnness tools with a final score of 11 and 0.81, respectively. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
19. Investigation of Imidazolium-Based Ionic Liquids as Additives for the Separation of Urinary Biogenic Amines via Capillary Electrophoresis.
- Author
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Kaczmarczyk, Natalia, Treder, Natalia, Kowalski, Piotr, Plenis, Alina, Roszkowska, Anna, Bączek, Tomasz, and Olędzka, Ilona
- Subjects
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BIOGENIC amines , *CAPILLARY electrophoresis , *MICELLAR electrokinetic chromatography , *IONIC liquids , *HOMOVANILLIC acid , *TETRAFLUOROBORATES , *SOLID phase extraction , *CAPILLARY liquid chromatography - Abstract
Ionic liquids (ILs), such as imidazoles, can be used to prevent the sorption of analytes onto the walls of the capillary. Prior works have confirmed that coating the capillary wall with a cationic layer can increase its surface stability, thereby improving the repeatability of the separation process. In this study, micellar electrokinetic chromatography (MEKC) is employed to evaluate how two ILs with different anions—namely, 1-hexyl-3-methylimidazolium chloride [HMIM+Cl−] and 1-hexyl-3-methylimidazolium tetrafluoroborate [HMIM+BF4−]—affect the separation efficiency for biogenic amines (BAs) such as metanephrine (M), normetanephrine (NM), vanilmandelic acid (VMA), and homovanillic acid (HVA) in urine samples. To this end, solid-phase extraction (SPE) is employed using different sample pH values, with the results demonstrating that HVA and VMA is easily extracted at a sample pH of 5.5, while a sample pH of 9.0 facilitated the extraction of M and NM. In the applied SPE protocol, selected analytes were isolated from urine samples using hydrophilic–lipophilic-balanced (HLB) columns and eluted with methanol (MeOH). The validation data confirmed the method's linearity (R2 > 0.996) for all analytes within the range of 0.25–10 µg/mL. The applicability of the optimized SPE-MEKC-UV method was confirmed by employing it to quantify clinically relevant BAs in real urine samples from pediatric neuroblastoma (NBL) patients. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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- View/download PDF
20. Quantitative estimation of enzymatic released specific oligosaccharides from Hericium erinaceus polysaccharides using CE-LIF.
- Author
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Deng, Yong, Zhao, Jing, and Li, Shaoping
- Subjects
HERICIUM erinaceus ,OLIGOSACCHARIDES ,POLYSACCHARIDES ,MICELLAR electrokinetic chromatography ,LASER-induced fluorescence - Abstract
Polysaccharides exhibit multiple pharmacological activities which are closely related to their structural features. Therefore, quantitatively quality control of polysaccharides based on their chemical characteristics is important for their application in biomedical and functional food sciences. However, polysaccharides are mixed macromolecular compounds that are difficult to isolate and lack standards, making them challenging to quantify directly. In this study, we proposed an improved saccharide mapping method based on the release of specific oligosaccharides for the assessment of Hericium erinaceus polysaccharides from laboratory cultured and different regions of China. Briefly, a polysaccharide from H. erinaceus was digested by β -(1-3)-glucanase, and the released specific oligosaccharides were labeled with 8-aminopyrene-1,3,6-trisulfonic-acid (APTS) and separated by using micellar electrokinetic chromatography (MEKC) coupled with laser induced fluorescence (LIF), and quantitatively estimated. MEKC presented higher resolution compared to polysaccharide analysis using carbohydrate gel electrophoresis (PACE), and provided great peak capacity between oligosaccharides with polymerization degree of 2 (DP2) and polymerization degree of 6 (DP6) in a dextran ladder separation. The results of high performance size exclusion chromatography coupled with multi-angle laser light scattering and refractive index detector (HPSEC-MALLS-RI) showed that 12 h was sufficient for complete digestion of polysaccharides from H. erinaceus. Laminaritriose (DP3) was used as an internal standard for quantification of all the oligosaccharides. The calibration curve for DP3 showed a good linear regression (R
2 > 0.9988). The limit of detection (LOD) and limit of quantification (LOQ) values were 0.05 μg/mL and 0.2 μg/mL, respectively. The recovery for DP3 was 87.32 (±0.03)% in the three independent injections. To sum up, this proposed method is helpful for improving the quality control of polysaccharides from H. erinaceus as well as other materials. [Display omitted] • Specific oligosaccharides were released from polysaccharides by selected enzyme. • Quantitative saccharide mapping method was firstly developed based on CE-LIF. • This method was superior to PACE, especially the feasibility of quantification. [ABSTRACT FROM AUTHOR]- Published
- 2023
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- View/download PDF
21. Separation and Detection of Tyrosine and Phenylalanine‐derived Oxidative Stress Biomarkers Using Microchip Electrophoresis with Electrochemical Detection.
- Author
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Weerasekara, Dhanushka B. and Lunte, Susan M.
- Subjects
- *
MICROCHIP electrophoresis , *MICELLAR electrokinetic chromatography , *OXIDATIVE stress , *TYROSINE , *REACTIVE nitrogen species , *OXYGEN reduction - Abstract
A method for the determination of selected aromatic amino acid biomarkers of oxidative stress using microchip electrophoresis with electrochemical detection is described. The separation of the major reaction products of phenylalanine and tyrosine with reactive nitrogen and oxygen species was accomplished using ligand exchange micellar electrokinetic chromatography with a PDMS/glass hybrid chip. Electrochemical detection was achieved using a pyrolyzed photoresist film working electrode. The system was evaluated for the analysis of the products of the Fenton reaction with tyrosine and phenylalanine, and the reaction of peroxynitrite with tyrosine. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
22. Understanding nonlinear composition dependency of enantioselectivity in chiral separation using mixed micelle.
- Author
-
Suzuki, Nozomu
- Subjects
- *
MICELLAR electrokinetic chromatography , *SURFACE tension measurement , *CRITICAL micelle concentration , *CHIRAL recognition , *CAPILLARY electrophoresis , *FLUORESCENCE spectroscopy , *MOLECULAR recognition - Abstract
[Display omitted] Mixtures of chiral and achiral building blocks of supramolecules exhibit interesting cooperative phenomena, indicated by the nonlinear composition dependence of the chiral properties. However, the nonlinear composition dependence of the enantioselectivity of mixed micelles is not well understood. It was hypothesized that in-depth understanding can be achieved by carefully investigating the composition dependence of the properties. In this work, the nonlinear composition dependence of the enantioselectivity was found for the mixed micelle of achiral and chiral N -acyl amino acids by micellar electrokinetic chromatography (MEKC). Capillary electrophoresis, circular dichroism (CD) spectroscopy, surface tension measurement, and fluorescence spectroscopy were used to investigate the mechanisms. Four mechanisms that could be causing the nonlinearity were investigated: (i) synergistic and antagonistic interactions of the surfactants; (ii) the chiral transfer from chiral to achiral surfactant; (iii) differences in the retention factor; and (iv) cooperative chiral recognition of the chiral and achiral surfactant. The investigation of the composition dependency of critical micelle concentration (CMC) and molar circular dichroism revealed that the effect of (i) and (ii) was negligibly small. The newly derived equations for (iii) and (iv) revealed that (iii) and (iv) have a major or medium effect on the nonlinear enantioselectivity. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
23. Development of transient trapping micellar electrokinetic chromatography coupled with mass spectrometry for steroids analysis.
- Author
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Manmana, Yanawut, Liu, Chenchen, Koino, Hiroshi, Sueyoshi, Kenji, Kitagawa, Fumihiko, Kubo, Takuya, and Otsuka, Koji
- Subjects
- *
MICELLAR electrokinetic chromatography , *ELECTROSPRAY ionization mass spectrometry , *ELECTRO-osmosis , *CAPILLARY electrophoresis , *MICELLAR solutions , *SODIUM dodecyl sulfate - Abstract
An on‐line sample preconcentration technique based on transient trapping (tr‐trapping) in micellar electrokinetic chromatography (MEKC) was applied for steroid detection with UV (tr‐trapping‐UV) and electrospray ionization mass spectrometry detection (tr‐trapping‐ESI‐MS). ESI‐MS was used to improve the sensitivity in MEKC. The MEKC separation was carried out using volatile ammonium formate as a background solution to facilitate the coupling with ESI‐MS. The partial introduction of a sodium dodecyl sulfate (SDS) micellar solution before the introduction of a sample solution to the capillary provided the effective preconcentration of analytes. At the same time, the SDS micelle would not enter the ESI‐MS system, so its interference in ESI‐MS detection was suppressed under the optimal condition, then five steroids can be separated by the developed method. In tr‐trapping‐ESI‐MS, an acidic condition of pH 3.5 was employed to suppress the electroosmotic flow, which can avoid micellar solution migrating to the MS instrument. The developed method showed that the micellar solution requires a twofold slower time than the sample to migrate along the column, which can prohibit the cause of the problem with the MS instrument and interference signal of SDS in the steroid's detection. The tr‐trapping‐ESI‐MS protocol showed up to 540‐fold enhancements of the peak intensity and 50‐fold improvement of the limit of detection compared with capillary zone electrophoresis using androsterone as a model sample. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
24. Simultaneous determination of ten nucleosides and bases in Ganoderma by micellar electrokinetic chromatography
- Author
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Feiya Sheng, Songsong Wang, Xiao Luo, Jianbo Xiao, Linfeng Hu, and Peng Li
- Subjects
Ganoderma ,Nucleosides ,Bases ,Micellar electrokinetic chromatography ,Quality assessment ,Nutrition. Foods and food supply ,TX341-641 - Abstract
Ganoderma (lingzhi) is a famous herbal medicine and edible supplement in oriental countries for a long history. In this study, a simple micellar electrokinetic chromatography (MEKC) method was established for the analysis of nucleosides and bases, the major bioactive components in Ganoderma for the first time. By optimizing the borate concentration, the sodium dodecyl sulfate (SDS) concentration and the pH value of running buffer, 10 nucleosides and bases achieved an ideal separation. In real sample analysis, the developed method was successfully used to determine the 10 target analytes in 23 batches of Ganoderma samples from different regions. Results indicated that contents of 10 investigated analytes in each sample showed obvious variation. The principal components analysis (PCA) and hierarchical cluster analysis (HCA) analysis classified the samples into three groups, and the HCA tree visualized the relationships which was mainly contributed by geographical partition. The results indicated geographical origin to be an important factor that affect the accumulation of nucleosides and bases in Ganoderma. In summary, this study provides a simple and practical strategy for quality assessment and cultivation reference of Ganoderma.
- Published
- 2022
- Full Text
- View/download PDF
25. Analytical quality by design-based development of a capillary electrophoresis method for Omeprazole impurity profiling.
- Author
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Modroiu, Adriana, Marzullo, Luca, Orlandini, Serena, Gotti, Roberto, Hancu, Gabriel, and Furlanetto, Sandra
- Subjects
- *
CAPILLARY electrophoresis , *MICELLAR electrokinetic chromatography , *OMEPRAZOLE , *SODIUM dodecyl sulfate , *CROSS-entropy method , *RESPONSE surfaces (Statistics) - Abstract
Omeprazole (OME) is a proton pump inhibitor used to treat gastroesophageal reflux disease associated conditions. The current study presents an Analytical Quality by Design-based approach for the development of a CE method for OME impurity profiling. The scouting experiments suggested the selection of solvent modified Micellar ElectroKinetic Chromatography operative mode using a pseudostationary phase composed of sodium dodecyl sulfate (SDS) micelles and n -butanol as organic modifier in borate buffer. A symmetric three-level screening matrix 37//16 was used to evaluate the effect of Critical Method Parameters, including Background Electrolyte composition and instrumental settings, on Critical Method Attributes (critical resolution values, OME peak width and analysis time). The analytical procedure was optimized using Response Surface Methodology through a Central Composite Orthogonal Design. Risk of failure maps made it possible to define the Method Operable Design Region, within which the following optimized conditions were selected: 72 mM borate buffer pH 10.0, 96 mM SDS, 1.45 %v/v n -butanol, capillary temperature 21 °C, applied voltage 25 kV. The method was validated according to ICH guidelines and robustness was evaluated using a Plackett-Burman design. The developed procedure enables the simultaneous determination of OME and seven related impurities, and has been successfully applied to the analysis of pharmaceutical formulations. [Display omitted] • A CE method for the analysis of Omeprazole and its impurities was set up. • Analytical Quality by Design principles were employed to develop the procedure. • The knowledge space was explored through a 37//16 symmetric screening matrix. • In Response Surface Methodology a Central Composite Orthogonal Design was used. • Probability maps allowed the Method Operable Design Region to be defined. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
26. A simple and green offline-online capillary electrophoresis stacking strategy for the simultaneous determination of hydrophobic compounds in complicated samples using sodium dodecyl sulfate as the solubilizer and pseudophase.
- Author
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Qin, Yaxin, Gao, Wei, Xu, Jian, Ping, Li, Tong, Shengqiang, Liu, Biao, and Chu, Chu
- Subjects
- *
SODIUM dodecyl sulfate , *SOLID phase extraction , *POLYACRYLAMIDE gel electrophoresis , *HYDROPHOBIC compounds , *CAPILLARY electrophoresis , *COMPLEX matrices , *CROSS-entropy method , *MICELLAR electrokinetic chromatography - Abstract
Capillary electrophoresis is a powerful analytical method featured with high separation efficiency, minimal sample requirements, and reduced organic solvents consumption. However, its low sensitivity hinders its wide application in determination of trace analytes especially for the weakly ionized hydrophobic compounds. Offline and Online capillary electrophoresis stacking methods are more favored to enhance detection sensitivity of analytes. The determination of two sesquiterpenes and an alkaloid from the dried root of Lindera aggregata merged as an example for developing a simple, sensitive and green method for the simultaneous determination of two hydrophobic compounds in complicated matrix samples. An offline-online capillary electrophoresis stacking strategy by integrating micro matrix solid phase dispersion with field-amplified sample stacking and micelle to cyclodextrin stacking has been developed for the simultaneous determination of dehydrocostus lactone, linderane, norisoboldine in complex matrices. The optimized parameters were set at 65 mM sodium dihydrogen phosphate, 35 % methanol, 180 s for sample injection and 210 s for cyclodextrin injection, 20 mM sodium dodecyl sulfate of sample matrix for online stacking; 1:1 sample to MCM-48, 180 s grinding time, and 1000 μL of 20 mM sodium dodecyl sulfate elution for offline procedure. Under the optimum conditions, the method showed good linearity with correlation coefficients (R2 ≥ 0.9927), low limits of detection within the range of 25–50 ng mL−1, satisfactory repeatability and reproducibility below 3.98 %, and acceptable recoveries between 94 % and 97 %. The developed method was successfully applied to two real samples, the root of L. aggregata and rat feces. Sodium dodecyl sulfate is firstly used as an eluent in micro matrix solid phase dispersion and plays a dual role throughout the analytical procedure, including extraction solvent in sample preparation and micelle pseudophase during online stacking. It brings great procedure convenience to the method. The sensitivity of this method can improve up to 1283-folds compared with the normal mode. Moreover, the overall strategy indicates satisfied green potential evaluated by greenness assessment tools. [Display omitted] • Developed a sodium dodecyl sulfate based offline-online CE stacking method. • To determine dehydrocostus lactone, linderane, norisoboldine simultaneously. • Sodium dodecyl sulfate serves as both solubilizer and pseudophase in this strategy. • The sensitivity improved up to 1283-folds compared with the normal mode. • It demonstrated satisfied green potential evaluated by greenness assessment tools. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
27. Capillary electrophoresis-UV analysis using silica-layer coated capillary for separation of seven phenolic acids and caffeine and its application to tea analysis
- Author
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Pattamaporn Hemwech, Apinya Obma, Sasinun Detsangiamsak, Supa Wirasate, Pimchai Chaiyen, Prapin Wilairat, and Rattikan Chantiwas
- Subjects
Caffeine ,Capillary electrophoresis ,Micellar electrokinetic chromatography ,Phenolic acids ,Silica coated capillary ,Tea ,Science ,Technology - Abstract
Abstract This work presents an innovative silica-layer coated capillary with comparison study of the silica-layer coated capillary and the fused-silica capillary for the separation of seven phenolic acids viz. p-hydroxyphenylacetic acid (PHPA), p-coumaric acid (PCA), p-hydroxybenzoic acid (PHBA), caffeic acid (CFA), (3,4-dihydroxyphenyl)acetic acid (DHPA), gallic acid (GLA), and 2,3,4-trihydroxybenzoic acid (THBA), together with caffeine (CF), by capillary electro-chromatography (CEC) and micellar electrokinetic chromatography (MEKC), respectively. The running buffer was 25.0 mM borate at pH 9.0, with addition of 50.0 mM sodium dodecyl sulfate for the MEKC mode. The non-coated capillary could not separate all seven phenolic acids by CEC or MEKC. This was achieved using the coated capillary for both CEC and MEKC. The innovative coated capillary with CEC had plate number N ≥ 2.0 × 104 m−1 and resolution R s ≥ 1.6 for all adjacent pairs of peaks. The capillary was also able to separate GLA and THBA which are structural isomers. Although MEKC mode provided comparable efficiency and selectivity, the reduced EOF of the coated capillary led to longer separation time. The linear calibration range of the seven phenolic acids and caffeine were different but the coefficients of determinations (r2) were all > 0.9965. The precisions of the relative migration times and peak area ratios of analyte to internal standard were 0.1–1.8% and 1.8–6.8%, respectively. There were no statistical differences in the efficiency of separation of the phenolic acids and caffeine for three coated capillaries. It was applied to the analysis of caffeine and phenolic acids in brewed tea using tyramine as the internal standard. The tea samples were diluted prior to analysis by CEC. The separation was less than 15 min. Caffeine, gallic acid and p-coumaric acid were detected and quantified. Caffeine and gallic acid contents were 10.8–15.0 and 2.6–4.8 mg g−1 dry tea leaves, respectively. p-Coumaric acid was detected in only one of the samples with a content of 0.4 mg g−1. Percent recoveries of spiked diluted samples were 90 ± 9 to 106 ± 13%, respectively. Article highlights Silica-layer coated capillary is first reported for simultaneous separation of seven phenolic acids by non-MEKC analysis. Performance between coated, and non-coated capillaries with analysis by CEC and MEKC were compared. Plate number, resolution, capillary reproducibility, and electroosmotic flow mobility are investigated. Graphical abstract
- Published
- 2021
- Full Text
- View/download PDF
28. Determination of four naphthalenediols in cosmetic samples by sweeping-micellar electrokinetic chromatography and a comparison with HPLC.
- Author
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Wang, Qian, Li, Xiaobin, Zheng, Zhihan, Liu, Huitao, and Gao, Yuan
- Subjects
MICELLAR electrokinetic chromatography ,MICELLAR liquid chromatography ,HIGH performance liquid chromatography ,DETECTION limit ,OINTMENTS ,STANDARD deviations - Abstract
A sweeping micellar electrokinetic chromatography (sweeping-MEKC) method was developed for the determination of 1,7-naphthalenediol, 2,3-naphthalenediol, 1,5-naphthalenediol and 2,7-naphthalenediol in cosmetics. Several parameters affecting sweeping-MEKC method were studied systematically and the separation conditions were optimized as 20 mM NaH
2 PO4 –110 mM SDS and 40% (v/v) MeOH (pH 2.4), with −22 kV applied voltage and UV detection at 230 nm. The sample matrix is 60 mmol L−1 NaH2 PO4 and sample introduction was performed at 3 psi for 6 s. Separation of the four naphthalenediols was completed in less than 17 min. Limit of detection (LOD) and limit of quantitation (LOQ) are 0.0045∼0.0094 μg mL−1 and 0.015∼0.031 μg mL−1 . Linear relationship (r2 > 0.999) is satisfactory at the range of 0.1–10 μg mL−1 . The developed method has been successfully applied to the determination of the four naphthalenediols in real cosmetic samples, with recoveries in foundation, sun cream and lotion in the range of 92.3%∼106.8% and relative standard deviation (RSD) less than 4.15%. A HPLC method described in the National Standards of the People's Republic of China was carried out for the comparison with the proposed method. The results showed that the proposed sweeping-MEKC method has the advantages of fast, low cost with comparative sensitivity. [ABSTRACT FROM AUTHOR]- Published
- 2022
- Full Text
- View/download PDF
29. Comparison of the Performance of Different Bile Salts in Enantioselective Separation of Palonosetron Stereoisomers by Micellar Electrokinetic Chromatography.
- Author
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Hu, Shaoqiang, Sun, Tao, Li, Rui, Zhang, Dongdong, Zhang, Yonghua, Yang, Zhuo, Feng, Ge, and Guo, Xuming
- Subjects
- *
MICELLAR electrokinetic chromatography , *BILE salts , *STEREOISOMERS , *CHIRAL recognition , *SODIUM cholate , *DIASTEREOISOMERS - Abstract
Bile salts are a category of natural chiral surfactants which have ever been used as the surfactant and chiral selector for the separation of many chiral compounds by micellar electrokinetic chromatography (MEKC). In our previous works, the application of sodium cholate (SC) in the separation of four stereoisomers of palonosetron (PALO) by MEKC has been studied systematically. In this work, the parameters of other bile salts, including sodium taurocholate (STC), sodium deoxycholate (SDC), and sodium taurodeoxycholate (STDC) in the separation of PALO stereoisomers by MEKC were measured and compared with SC. It was found that all of four bile salts provide chiral recognition for both pairs of enantiomers, as well as achiral selectivity for diastereomers of different degrees. The structure of steroidal ring of bile salts has a greater impact on the separation than the structure of the side chain. The varying separation results by different bile salts were elucidated based on the measured parameters. A model to describe the contributions of the mobility difference of solutes in the aqueous phase and the selectivity of micelles to the chiral and achiral separation of stereoisomers was introduced. Additionally, a new approach to measure the mobility of micelles without enough solubility for hydrophobic markers was proposed, which is necessary for the calculation of separation parameters in MEKC. Under the guidance of derived equations, the separation by SDC and STDC was significantly improved by using lower surfactant concentrations. The complete separation of four stereoisomers was achieved in less than 3.5 min by using 4.0 mM of SDC. In addition, 30.0 mM of STC also provided the complete resolution of four stereoisomers due to the balance of different separation mechanisms. Its applicability for the analysis of a small amount of enantiomeric impurities in the presence of a high concentration of the effective ingredient was validated by a real sample. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
30. Capillary Electrophoresis Mass Spectrometry: Developments and Applications for Enantioselective Analysis from 2011–2020.
- Author
-
Shamsi, Shahab A. and Akter, Ferdoushi
- Subjects
- *
CAPILLARY electrophoresis , *MICELLAR electrokinetic chromatography , *CAPILLARY electrochromatography - Abstract
It is now more than 25 years since the first report of enantioselective analysis by capillary electrophoresis-mass spectrometry (CE-MS) appeared. This article reviews the power of chiral CE-MS in resolving issues on the use of chiral selector incompatibility with MS and poor detectability encountered for chiral compounds by UV detection. The review begins with the general principles, requirements, and critical aspects of chiral CE-MS instrumentation. Next, the review provides a survey of MS-compatible chiral selectors (CSs) reported during the past decade, and the key achievements encountered in the time period using these CSs. Within the context of the strategies used to combine CE and MS, special attention is paid to the approaches that feature partial filling technique, counter-migration techniques, and direct use of CS, such as molecular micelles. In particular, the development and application of moving and fixed CS for EKC-MS, MEKC-MS, and CEC-MS demonstrate how various chiral compounds analyses were solved in a simple and elegant way during the 2010–2020 review period. The most noteworthy applications in the determination of chiral compounds are critically examined. The operating analytical conditions are detailed in the Tables, and the authors provide commentary on future trends of chiral separations by CE-MS. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
31. Determination of the Monoclonal Antibody Tocilizumab by a Validated Micellar Electrokinetic Chromatography Method.
- Author
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Zayed, Sahar and Belal, Fathalla
- Abstract
Tocilizumab is a monoclonal antibody used in the treatment of several inflammatory and autoimmune diseases as well as cancers. Tocilizumab improves clinical outcomes and reduce mortality rates in patients with COVID-19 disease. A novel, simple and reliable method was developed to determine tocilizumab using micellar electrokinetic chromatography (MEKC). Separation of tocilizumab and the internal standard, methotrexate, was achieved with a background electrolyte consisting of phosphoric acid buffer and sodium dodecyl sulfate (SDS) with UV detection at 195 nm. The method was linear in the concentration range from 10 to 250 µg/mL with correlation coefficient greater than 0.995. The method was successfully applied to the analysis of human and rat plasma samples with good recoveries. Sample preparation involved protein precipitation followed by dilution of the supernatant. The intra‐ and inter-day precisions were less than 5%, the accuracy varied from − 2.71 to 3.84%. The proposed method has acceptable analytical performance and could be applied in future clinical and pharmacokinetic studies including anticancer therapy. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
32. Khellin and visnagin in different organs of Ammi visnaga and Ammi majus.
- Author
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Adımcılar, Veselina, Beyazit, Neslihan, and Erim, F. Bedia
- Subjects
MICELLAR electrokinetic chromatography ,FLOWER seeds ,TRADITIONAL medicine - Abstract
Ammi visnaga and Ammi majus are plants that have long been used in traditional medicine. Nowadays, both herbs are commercially marketed as alternative medicines in different formulations. The main active ingredients of A. visnaga are known as khellin and visnagin. Information on the quantitative amounts of both bioactive substances in the different organs of the plant is lacking. This study aims to determine the amounts of these two active substances in the five organs of both plants from Turkey and provide information to the pharmaceutical industry. For this purpose, a fast and reliable micellar electrokinetic chromatography method was applied. It was found that Ammi visnaga, flowers, seeds, and leaves are good sources of both khellin and visnagin. Ammi majus only contains khellin in its seeds and flowers. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
33. Purines recognition and quantitative analysis by surface-enhanced Raman spectroscopy.
- Author
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Shi, Xiao-Yang, Li, Yun-Chuan, Yu, Lei, Xiao, Bo-Huai, Qian, Gong-Ming, and Guo, Jing
- Subjects
- *
MICELLAR liquid chromatography , *SERS spectroscopy , *MICELLAR electrokinetic chromatography , *PURINES , *CAPILLARY electrophoresis , *HIGH performance liquid chromatography , *QUANTITATIVE research - Abstract
[Display omitted] • A simple method for the quantitative analysis of purines in beer has been developed. • The SERS probe prepared using a simple electrochemical treatment method on a Ag wire, exhibits a Raman enhancement factor of ∼106. • A linear relationship between SERS intensity and purine concentration in the range of 10−5 to 10−1 mg/mL was obtained for quantification of purines. • The recovery rate of each purine base using the SERS probe exceeds 80% for market beer. The common quantification methods of purines, including high-performance liquid chromatography, micellar electrokinetic chromatography, reverse phase ion pair chromatography, and capillary zone electrophoresis, have been used for the analysis of purines. These conventional techniques are limited by long operation times, large sample volumes, requirements for pretreatment and separation processes, or sophisticated, bulky and expensive equipment. Here, we have developed a simple method to prepare a probe for the quantitative analysis of purines using the surface-enhanced Raman scattering (SERS) method. The SERS probe is a rough Ag wire obtained with simple electrochemical treatment, which is optimized to reach the maximum SERS signal enhancement. The Raman enhancement factor (EF) of Ag wire after roughening can reach ∼106. Under optimized conditions, the rough Ag wire is capable of recognizing four purine bases (namely, guanine, adenine, hypoxanthine, and xanthine) in the range of 10−5 to 10−1 mg/mL with a linear relationship between SERS intensity of signature peak and purine concentration. The recovery rate of each purine base is higher than 80% in the mixture of four purines. The overall method was successfully applied to the monitoring of the level of purines in marketplace beer beverages. The novel wire-based SERS sensor used with portable Raman spectroscopy is prospective in diet safety and personalized point-of-care medical detection. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
34. Validated green micellar electrokinetic capillary chromatography for simultaneous determination of simvastatin and sitagliptin phosphate binary mixture in pharmaceutical formulation.
- Author
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Kamal, Miranda F., Morshedy, Samir, Saad, Dina A., and Moneeb, Marwa S.
- Subjects
- *
ELECTROKINETICS , *ATHEROSCLEROTIC plaque , *CARDIOVASCULAR disease diagnosis , *LIPOPROTEINS - Abstract
Diabetics are liable to fatal atherosclerotic cardiovascular diseases. It is clinically attributed to their imbalanced plasma lipoproteins. Fixed‐dose combination "polypill" of simvastatin (10 mg) and sitagliptin phosphate (100 mg) is mainly indicated for the treatment of diabetic dyslipidemia. Novel green micellar electrokinetic capillary chromatographic method has been developed for simultaneous determination of simvastatin and sitagliptin phosphate in binary synthetic mixtures and their pharmaceutical formulation. Separation was achieved using a deactivated fused silica capillary (50 cm effective length × 50 μm id) through a background running electrolyte of 100 mM borate buffer (pH 9.1) and 100 mM sodium dodecyl sulfate. Diode array detection was set at 238 and 210 nm for simvastatin and sitagliptin phosphate, respectively. All experimental parameters were closely varied and optimized. Both drugs declared good linearities over the range of 10–100 μg/mL. Proposed study was validated according to International Council for Harmonization guidelines. It was applied to the assay of laboratory‐made binary mixtures and marketed tablets. Electrophoretic assay was compared with a reported spectrophotometric one. Satisfactory t‐test and F‐ratio indicated insignificant differences between both methods. Moreover, it is the first capillary electrophoretic simultaneous assay for simvastatin and sitagliptin phosphate, and fits a linear correlation with the green analytical attributes. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
35. Open-Channel Separation Techniques for the Characterization of Nanomaterials and Their Bioconjugates for Drug Delivery Applications
- Author
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Lee, Jiwon, Coreas, Roxana, Zhong, Wenwan, and Kumar, Challa S.S.R., editor
- Published
- 2019
- Full Text
- View/download PDF
36. Determination of the Nucleoside Reverse Transcriptase Inhibitors Lamivudine, Stavudine, and Didanosine in Human Urine by Micellar Electrokinetic Chromatography Using the Ionic Liquid-Based Cationic Surfactant 1-Tetradecyl-3-Methylimidazolium Bromide.
- Author
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Xu, Lei, Lu, Jing, Meng, Weiqi, and Cui, Fengjuan
- Subjects
- *
NUCLEOSIDE reverse transcriptase inhibitors , *MICELLAR electrokinetic chromatography , *LAMIVUDINE , *CATIONIC surfactants , *NUCLEOSIDE synthesis , *BROMINE - Abstract
Micellar electrokinetic chromatography (MEKC) with ultraviolet detection was employed for the simultaneous determination of the nucleoside reverse transcriptase inhibitors lamivudine, stavudine and didanosine with the ionic liquid-based cationic surfactant 1-tetradecyl-3-methylimidazolium bromide ([C14MIm]Br) as the pseudostationary phase. The composition, pH, and concentration of running buffer, surfactant concentration, separation voltage, and injection time were optimized. In comparison with conventional cationic surfactants, improved separation was observed using [C14MIm]Br. The applicability of the method was demonstrated by the analysis of human urine. The method exhibited wide linear ranges with limits of quantitation of 0.5, 0.3, and 1.0 μg/mL for lamivudine, stavudine, and didanosine, respectively. The intra-day and inter-day accuracies were from 91.5% to 114.0%. The precision, expressed as relative standard deviation (RSD), was less than 12.6% for the peak area. The recoveries of the analytes in the samples were between 91.8% and 97.3%. This approach is convenient, rapid, and economical for these analytes in biological samples. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
37. A sweeping-micellar electrokinetic chromatography method for the detection of three chlorophenols in cosmetic samples.
- Author
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Zheng, Zhihan, Li, Xiaobin, Gao, Fangfang, Liu, Huitao, and Gao, Yuan
- Subjects
MICELLAR liquid chromatography ,MICELLAR electrokinetic chromatography ,CHLOROPHENOLS ,SODIUM dodecyl sulfate ,CHROMATOGRAPHIC analysis ,OINTMENTS ,SIGNAL-to-noise ratio - Abstract
A sweeping micellar electrokinetic chromatography (sweeping-MEKC) enrichment model was established for the determination of three chlorophenols (CPs) in cosmetics, namely, bithionol, pentachlorophenol (PCP), and 2,4,6-trichlorophenol (2,4,6-TCP). The optimum electrophoretic conditions were 20 mM NaH
2 PO4 -80 mM sodium dodecyl sulfate (SDS) and 30% (v/v) acetonitrile (pH 2.3). The optimum on-line concentration conditions were as follows: sample matrix, 100 mM NaH2 PO4 ; pressure injection at 20.67 kPa (3 psi) for 25 s. The linear range of bithionol, PCP, and 2,4,6-TCP are 0.20–4.00 μg mL−1 , 0.10–2.00 μg mL−1 , and 0.05–2.00 μg mL−1 respectively, with correlation coefficient (r) over 0.9972. The limits of detection (LOD) based on three times the signal-to-noise ratio (S/N = 3) are in the range of 0.0061–0.024 μg mL−1 . Recoveries for the three CPs in powder and lotion samples are between 79.7 and 110.2% with relative standard deviation (RSD) of 1.38–5.54% and 92.2–121.3% with RSD of 0.72–6.09%, respectively. The proposed method can provide reference for the determination of trace CPs in different sample matrix. [ABSTRACT FROM AUTHOR]- Published
- 2021
- Full Text
- View/download PDF
38. Simultaneous separation and determination of four active ingredients in Picria fel‐terrae Lour. and its preparations by micellar electrokinetic chromatography.
- Author
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Wang, Hua, Yang, Yuhang, Guo, Jing, Wang, Mengli, Zhang, Hongfen, Zhang, Guangbin, Chang, Ruimiao, and Chen, Anjia
- Abstract
Introduction: Picfeltarraenins IA, IB and IV and acteoside are the four bioactive ingredients of Picria fel‐terrae Lour. Their pharmacological effects include central inhibitory, cardiovascular, anti‐inflammatory, anti‐pyretic, analgesic, anti‐bacterial, antioxidative and anti‐tumor effects. Objective: We aimed to develop an efficient micellar electrokinetic chromatography (MEKC) method modified with mixed organic solvents for the simultaneous separation and determination of the four components in Picriae Herba and its formulations. Methods: Method optimization was carried out by investigating influences of significant factors on the separation, and this method was successfully applied for the determination of the four components in Picriae Herba and its formulations. Results: The optimal running buffer was composed of 20 mM sodium tetraborate, 40 mM sodium cholate, 10% (v/v) methanol and 10% (v/v) isopropanol (pH 9.76). The separation voltage was 18 kV, the temperature was 25°C and the detection wavelength was 266 nm. Under the optimal separation conditions, the baseline separation of four components was achieved in less than 14 min. The correlation coefficients of the calibration curves were 0.9984–0.9995 for the analytes. The intraday and interday precision ranged from 1.5% to 2.5% and from 1.4% to 5.0%, respectively. Recoveries of analytes varied from 96.6% to 104.1%. Conclusion: The method was proved suitable for the determination of four components in Picriae Herba and its formulations. Good performance was obtained under optimal conditions, and the method provides an effective tool for the quality control of Picriae Herba and its formulations. A micellar electrokinetic chromatography (MEKC) modified with mixed organic solvents method employing methanol and isopropanol for the simultaneous separation and determination of Picfeltarraenins IA and IB, picfeltarraenin IV and acteoside in Picriae Herba was established. The method was successfully applied to the determination of four components in Picriae Herba and its formulations. In addition, the method provides an effective reference of the quality control of Picriae Herba and its formulations. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
39. Ionic Liquids in Electrophoretic Separation and Preconcentration Processes.
- Author
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Bessonova, E. A., Kartsova, L. A., and Moskvichev, D. O.
- Subjects
- *
MICELLAR electrokinetic chromatography , *IONIC liquids , *ELECTROPHORETIC deposition , *CAPILLARY electrophoresis , *BLOOD plasma , *PLANT extracts , *AMINO acids - Abstract
Ionic liquids (ILs) are widely used in separation methods such as chromatography and capillary electrophoresis due to their unique properties. This review discusses the prospects for using imidazole-based ILs as electrophoretic system modifiers in capillary zone electrophoresis and micellar and microemulsion electrokinetic chromatography for the determination of biologically active substances (amino acids, catecholamines, steroid hormones, and polyphenolic antioxidants). New approaches to selective electrophoretic determination and efficient online preconcentration of analytes with the participation of imidazolium ILs are considered; the application of developed approaches to the analysis of natural objects (urine, blood plasma, and plant extracts) is exemplified. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
40. Micellar Electrokinetic Chromatographic Analysis of Historic Dyes and Their Photofading Products.
- Author
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Dervishian, Aimee, Goodwin, Justin, King, Connor, and Copper, Christine
- Abstract
Since the early 20th century, the Monroe Chemical Company's Putnam Fadeless Dyes were used by consumers to dye numerous types of textiles. In this work, we describe a novel micellar electrokinetic chromatographic (MEKC) method employing sodium cholate and acetonitrile in the background electrolyte that can be used to analyze these dyes. Specifically, Putnam Fadeless Dyes were successfully extracted from linen samples colored with them and the components of each dye were separated and detected using MEKC. These results compared favorably to MEKC data from standard dye solutions. Dyed linen samples were also exposed to simulated sunlight and MEKC was used to analyze dyes extracted from them. The resulting data showed that photofading altered the amount of dye in the fabric but not its chemical composition. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
41. Comparison of aqueous and non-aqueous capillary electrophoresis for the determination of four benzalkonium chloride homologues in compound chemical disinfectants.
- Author
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Yao K, Jiang R, Wang P, Zhang J, Shao B, and Ding X
- Abstract
A new method was established for the simultaneous analysis of four homologous benzalkonium chlorides (dodecyldimethylbenzyl ammonium chloride, tetradecyldimethylbenzyl ammonium chloride, hexadecyldimethylbenzyl ammonium chloride, and octadecyldimethylbenzyl ammonium chloride) in compound chemical disinfectants using non-aqueous capillary electrophoresis (CE) based on a micellar electrokinetic chromatography mode with direct ultraviolet detection. The separation was performed on an uncoated fused quartz capillary with a total length of 60.2 cm and a diameter of 25 μm. The separation buffer consisted of a mixture of methanol/acetonitrile (60:40, v/v) containing 70 mmol/L sodium acetate, 60 mmol/L trifluoroacetic acid and 20 mmol/L sodium dodecyl sulfate. The sample buffer was a methanol solution containing only 2 mmol/L trifluoroacetic acid. The separation voltage was set at 8 kV with a working current of approximately 2.3 μA. The detection wavelength was 214 nm. Under optimal conditions, the limit of detection and limit of quantification for these four benzalkonium chlorides (BACs) were 1.0 mg/L and 5.0 mg/L, respectively. Good linearities were observed in the concentration ranges from 5.0 to 100.0 mg/L, with correlation coefficients above 0.999 for all compounds. The recoveries of these four BACs ranged from 92.5 % to 109.1 % with relative standard deviations below 4.7 %. With the new method, all four BACs could be analyzed in a single injection. In contrast, the aqueous CE method in the National Standard GB/T 26369-2020 only allowed for the simultaneous analysis of the first three homologous. The new method demonstrated the improved peak shape compared to the aqueous CE method and then was successfully applied to the analysis of 19 commercially available samples, such as object table disinfectants, hand sanitizers, and disinfectant wipes, which claimed to contain quaternary ammonium compound. The results obtained using the new method were compared with those of the aqueous CE of the National Standard Method, and no statistically significant differences were observed. The new method is simple in pre-treatment and provides accurate results, making it highly suitable for routine analysis., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 Beijing Center for Disease Pvevention and Control.)
- Published
- 2024
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42. Effect of Modifiers on the Electrophoretic Separation and Intercapillary Preconcentration of Biologically Active Compounds.
- Author
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Kravchenko, A. V. and Kartsova, L. A.
- Subjects
- *
BIOACTIVE compounds , *CAPILLARY electrophoresis , *SEPARATION (Technology) , *MICELLAR electrokinetic chromatography , *IONIC liquids , *ELECTROPHORETIC deposition , *HYDROPHILIC interaction liquid chromatography - Abstract
The use of modifiers in the electrophoretic separation of multicomponent mixtures makes it possible to significantly expand the analytical capabilities of capillary electrophoresis. Modifiers of electrophoretic systems, different in nature and properties, can perform different functions: form stationary and pseudo-stationary phases, prevent the adsorption of analytes on the walls of a quartz capillary, help to reduce the limits of detection for analytes during preconcentration, etc. In this review, various versions of the application of modifiers to the electrophoretic separation and preconcentration of analytes of different nature are considered on an example of imidazolium ionic liquids, which can act as stationary and pseudo-stationary phases, and also directly participate in the online preconcentration of analytes of hydrophilic and hydrophobic nature. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
43. Analysis of Natural Dyes from Historical Objects by High Performance Liquid Chromatography and Electromigration Techniques.
- Author
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Zasada-Kłodzińska, Daria, Basiul, Elżbieta, Buszewski, Bogusław, and Szumski, Michał
- Subjects
- *
HIGH performance liquid chromatography , *NATURAL dyes & dyeing , *ELECTRODIFFUSION , *MICELLAR electrokinetic chromatography , *DYES & dyeing - Abstract
Based on material published between 1989 and 2018 in this paper high performance liquid chromatography and electromigration techniques used in studies of natural dyes that can be found in historical objects are rewieved. Different aspects of analysis have been discussed: the stationary and mobile phase, the choice of sample solvent, methods of extraction and detection, including sensitivity parameters, such as LOD and/or LOQ. The discussed dyes have been divided into three categories (a) red antraquinone dyes along with dyes extracted from bark and tree juices, (b) yellow flavonoid dyes and saffron and (c) blue indigoid dyes. The main markers (chromophores or auxochromes) typical for each dye source were presented which allows to identify specific species of source plants and animals. The first part of the study involved the analysis of most critical findings when it comes to HPLC or represented an significant analytical approach. The second part of the study is focused on different aspects of electromigration techniques application in analysis of natural dyes with special attention paid on such parameters as the running buffer/mobile phase composition and sample solvent. Detection methods along with LOD and LOQ comparison in HPLC and electromigration techniques were also discussed. Methods of sample preparation, such as hydrolysis and extraction, used in HPLC and electromigration techniques were also briefly discussed. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
44. Study Findings on Electrokinetics Discussed by Researchers at Pontifical Catholic University (Determination of vitamins K1 and K3 in green tea and in pharmaceutical supplements by capillary micellar electrokinetic chromatography).
- Subjects
MICELLAR electrokinetic chromatography ,MENADIONE ,ELECTROKINETICS ,GREEN tea ,RESEARCH personnel - Abstract
Researchers at Pontifical Catholic University in Rio de Janeiro, Brazil have developed a method for determining the levels of vitamins K1 and K3 in green tea and pharmaceutical supplements using capillary micellar electrokinetic chromatography (MEKC). The method was optimized for electrophoretic separation and achieved better peak efficiency. The researchers found that the method provided reliable and sensitive measurements of the vitamins with low solvent consumption and minimal waste generation. Comparative tests with a reference method based on liquid chromatography yielded agreement of results. [Extracted from the article]
- Published
- 2024
45. Patent Issued for Uniformly pressing micro-valve system for controlling path of fluids in miniaturized capillary connections and methods of fabrication (USPTO 11931741).
- Subjects
CAPILLAROSCOPY ,FLUID control ,CAPILLARY electrophoresis ,CAPILLARIES ,MICELLAR electrokinetic chromatography ,PATENTS ,BIOENGINEERING - Abstract
Princeton Biochemicals Inc. has been granted a patent for a micro-valve system that regulates fluid flow in miniaturized capillary connections. The system utilizes two small diameter capillaries connected by a flexible plastic tube, which is protected by thicker plastic tubes. A uniform-pressure pressing system is employed to block fluid passage within the capillaries, with the opening and closing mechanism controlled by applying or releasing external pressure. This innovation addresses the challenges of sample preparation in bioanalysis and has potential applications in chromatography and electrophoresis. The patent provides a comprehensive description of the micro-valve system, including its components and claims. [Extracted from the article]
- Published
- 2024
46. Comparison of the Performance of Different Bile Salts in Enantioselective Separation of Palonosetron Stereoisomers by Micellar Electrokinetic Chromatography
- Author
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Shaoqiang Hu, Tao Sun, Rui Li, Dongdong Zhang, Yonghua Zhang, Zhuo Yang, Ge Feng, and Xuming Guo
- Subjects
chiral separation ,micellar electrokinetic chromatography ,capillary electrophoresis ,palonosetron hydrochloride ,bile salts ,Organic chemistry ,QD241-441 - Abstract
Bile salts are a category of natural chiral surfactants which have ever been used as the surfactant and chiral selector for the separation of many chiral compounds by micellar electrokinetic chromatography (MEKC). In our previous works, the application of sodium cholate (SC) in the separation of four stereoisomers of palonosetron (PALO) by MEKC has been studied systematically. In this work, the parameters of other bile salts, including sodium taurocholate (STC), sodium deoxycholate (SDC), and sodium taurodeoxycholate (STDC) in the separation of PALO stereoisomers by MEKC were measured and compared with SC. It was found that all of four bile salts provide chiral recognition for both pairs of enantiomers, as well as achiral selectivity for diastereomers of different degrees. The structure of steroidal ring of bile salts has a greater impact on the separation than the structure of the side chain. The varying separation results by different bile salts were elucidated based on the measured parameters. A model to describe the contributions of the mobility difference of solutes in the aqueous phase and the selectivity of micelles to the chiral and achiral separation of stereoisomers was introduced. Additionally, a new approach to measure the mobility of micelles without enough solubility for hydrophobic markers was proposed, which is necessary for the calculation of separation parameters in MEKC. Under the guidance of derived equations, the separation by SDC and STDC was significantly improved by using lower surfactant concentrations. The complete separation of four stereoisomers was achieved in less than 3.5 min by using 4.0 mM of SDC. In addition, 30.0 mM of STC also provided the complete resolution of four stereoisomers due to the balance of different separation mechanisms. Its applicability for the analysis of a small amount of enantiomeric impurities in the presence of a high concentration of the effective ingredient was validated by a real sample.
- Published
- 2022
- Full Text
- View/download PDF
47. A simple and efficient sequential electrokinetic and hydrodynamic injections in micellar electrokinetic chromatography method for quantification of anticancer drug 5‐fluorouracil and its metabolite in human plasma.
- Author
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Semail, Nadhiratul‐Farihin, Noordin, Siti Salmah, Keyon, Aemi Syazwani Abdul, Waras, Maisarah Nasution, Saad, Bahruddin, Kamaruzaman, Sazlinda, Mohamad Zain, Nur Nadhirah, Azizi, Juzaili, Aziz, Mohd Yusmaidie, and Yahaya, Noorfatimah
- Abstract
A simple and sensitive preconcentration strategy using sequential electrokinetic and hydrodynamic injection modes in micellar electrokinetic chromatography with diode array detection was developed and applied for the separation and determination of anticancer agent, 5‐fluorouracil and its metabolite, 5‐fluoro‐2′‐deoxyuridine, in human plasma. Sequential injection modes with increased analyte loading capacity using the anionic pseudo‐stationary phase facilitated collection of the dispersed neutral and charged analytes into narrow zones and improved sensitivity. Several important parameters affecting sample enrichment performance were evaluated and optimized in this study. Under the optimized experimental conditions, 614‐ and 643‐fold and 782‐ and 803‐fold sensitivity improvement were obtained for 5‐fluorouracil and its metabolite when compared with normal hydrodynamic and electrokinetic injection, respectively. The method has good linearity (1–1,000 ng/ml) with acceptable coefficient of determination (r2 > 0.993), low limits of detection (0.11–0.14 ng/ml) and satisfactory analyte relative recovery (97.4–99.7%) with relative standard deviations of 4.6–9.3% (n = 6). Validation results as well as the application to analysis of human plasma samples from cancer patients demonstrate the applicability of the proposed method to clinical studies. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
48. Dispersive liquid-liquid microextraction followed by sweeping micellar electrokinetic chromatography-tandem mass spectrometry for determination of six breast cancer drugs in human plasma.
- Author
-
Mlinarić, Zvonimir, Turković, Lu, and Sertić, Miranda
- Subjects
- *
MICELLAR liquid chromatography , *LIQUID chromatography-mass spectrometry , *MASS spectrometry , *ANTINEOPLASTIC agents , *BREAST cancer , *DRUG monitoring , *MATRIX effect - Abstract
• The first CE-MS method for quantitation of six breast cancer drugs was developed. • Protein precipitation with dispersive liquid-liquid microextraction was employed. • Compatibility and optimization of MEKC and MS techniques are discussed. • The sweeping MEKC-MS/MS method was fully validated according to the ICH guidelines. • Application to patient plasma proved suitable for therapeutic drug monitoring. Herein, we have developed a novel method of aqueous-sample dispersive liquid-liquid microextraction (AqS-DLLME) followed by sweeping micellar electrokinetic chromatography-tandem mass spectrometry (MEKC-MS/MS) for simultaneous determination of breast cancer drugs letrozole, anastrozole, palbociclib, ribociclib, abemaciclib, and fulvestrant in human plasma. Coupling of MEKC to MS was possible due to the use of ammonium perfluorooctanoate (APFO) as a volatile surfactant. The MEKC and MS conditions were optimized to achieve a fast, sensitive, selective, and green analysis enabling full separation of the analytes within 16 min. Electrophoretic buffer was 125 mM APFO at apparent pH 10.5 in 32 % MeOH, while sheath liquid was 70 % MeOH with 0.2 % formic acid, delivered at 10 µL/min. Excellent extraction recoveries from plasma ranging from 89.4 to 104.9 % were obtained with a combination of protein precipitation and DLLME. The developed method was validated according to the ICH guidelines. Remarkable selectivity, accuracy (bias < 6.7 %), precision (RSD < 15.8 %), and stability (bias < 10.4 %) with insignificant matrix effect (RSD < 14.0 %) and no carry-over were obtained over a wide range of concentrations. Linearity with inter-day slope RSD lower than 8.7 % was demonstrated. With this method, very low concentrations could be detected after the injection of only 68.7 nL of the sample. The method was applied to plasma samples from six women currently receiving breast cancer treatment. Determined concentrations of the drugs of interest agreed with concentrations found in clinical studies, thus proving the suitability of the developed method for therapeutic drug monitoring as a superior alternative to published LC-MS methods. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
49. Capillary electrophoresis separations with deep eutectic solvents as greener separation media: A proof-of-concept study.
- Author
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Ding, Sihui, Xu, Yu, Xue, Song, Li, Ang, and Zhang, Qi
- Subjects
- *
CAPILLARY electrophoresis , *MICELLAR electrokinetic chromatography , *EUTECTICS , *NAPHTHALENE derivatives , *SOLVENTS , *HYDROPHOBIC interactions , *ISOMERS - Abstract
• The first successful application of DESs as separation media in CE. • A comprehensive assessment of the fundamental aspects of this DES-type CE medium. • The first observation of Tween micelles in a DES. • The DES-type CE medium can be used for establishing both CZE and MEKC systems. Capillary electrophoresis (CE) has conventionally been classified into aqueous and non-aqueous categories based on the types of buffer solvents employed. Traditionally, non-aqueous CE has always been associated with the use of organic solvents, which are considered hazardous to health and environmentally detrimental. In this work, we introduce deep eutectic solvents (DESs) as CE separation media for the first time, presenting a novel and environmentally friendly approach to CE separations. The DES employed consists of proline and urea (Proline:Urea, PU), both of which are naturally occurring compounds that are readily available, cost-effective, and environmentally benign. Various fundamental aspects of the DES-type CE media were investigated, including thermal property, viscosity, electroconductivity, Joule heating effect, and compatibility with detectors. A simulated complex mixture of ten naphthalene-based compounds with varied charges and sizes was separated using the DES-based medium in capillary zone electrophoresis (CZE) mode. Moreover, we also established a DES-based micellar electrokinetic chromatography (MEKC) system utilizing Tween-20 as the surfactant. Six structurally similar naphthalene derivatives (isomers) that couldn't be resolved by CZE were effectively separated due to their strong hydrophobic interaction with Tween-20 micelles within the DES medium. Given that DESs are "designer" solvents with highly tunable properties and environmentally friendly characteristics, this study demonstrates the potential of employing DESs as an alternative to organic solvents for greener CE separations. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
50. On-line concentration and separation of multiple derivatized monosaccharides from edible fruit with cyclodextrin-encapsulated sweeping by micellar electrokinetic chromatography.
- Author
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Jin, Huang-Fei, Shi, Ying, Shen, Qian-Xue, Cao, Jun, and Ye, Li-Hong
- Subjects
- *
MICELLAR electrokinetic chromatography , *MONOSACCHARIDES , *SODIUM dodecyl sulfate , *COMPLEX matrices , *FRUIT , *EDARAVONE - Abstract
• An on-line enrichment method using γ-CD encapsulated sweeping-MEKC was presented. • Monosaccharides were derivatized with 1-phenyl-3-methyl-5-pyrazolone. • The method can on-line preconcentrate trace monosaccharides in Jujube. • The SEFs ranged from 53 to 82 compared with typical injection. An on-line enrichment and separation of multiple derivatized monosaccharides with cyclodextrin-encapsulated sweeping (CDES) by micellar electrokinetic chromatography (MEKC) was presented. Five monosaccharides (L-(−)-Mannose, D-(+)-Glucose, D-(−)-Ribose, D-(+)-Xylose, and L-(+)-Rhamnose) were derivatized with 1-phenyl-3-methyl-5-pyrazolone, subsequently concentrated and separated by MEKC. The optimized conditions were as follows: 50 mM phosphoric acid (PA), 100 mM sodium dodecyl sulfate (SDS), and 30 % (v/v) methanol in background solution; 140 s injection of sample solution containing 50 mM CD and 100 mM PA, followed by 90 s injection of 40 mM SDS solution. Under the optimized conditions, the correlation coefficients ≥ 0.9953, and the limits of detection ranged from 4.2 to 7.4 ng/mL. Relative standard deviation values ranged from 0.24–4.23 %, and sensitivity enrichment factors were in the range of 53–82 compared with typical injection (50 mbar, 3 s). The CDES-MEKC method was successfully applied to Jujube with good recoveries of 84.22–104.33 %. The method provides new ideas for the on-line enrichment and detection of trace monosaccharides and even other target analytes in foods with complex matrices. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
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