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Based on the diazotization-coupling reaction, a new, simple, and sensitive spectrophotometric method for determining of a trace amount of (BPF) is presented in this paper. Diazotized metoclopramide reagent react with bisphenol F produces an orange azo-compound with a maximum absorbance at 461 nm in alkaline solution. The experimental parameters were optimized such as type of alkaline medium, concentration of NaOH, diazotized metoclopramide amount, order additions, reaction time, temperature, and effect of organic solvents to achieve the optimal performance for the proposed method. The absorbance increased linearly with increasing bisphenol F concentration in the range of 0.5-10 μg mL-1 under ideal conditions, with a correlation coefficient of 0.9931 and a detection limit of 0.15 μg mL-1. The effect of different temperatures and different extraction time was studied on the leaching out and the data indicates that as time and temperature rising, the concentration of BPF leached out of all thermal papers increased. To confirm that extracts from thermal papers contained BPF, samples containing the analytic were subjected to high-performance liquid chromatography (HPLC-UV detector) analysis. The analysis was carried out on a C18 column with a mobile phase of acetonitrile/water (55/45v:v), and the detection was conducted spectrophotometrically at 230 nm. The retention time of standard BPF was determined to be 5.649 min and the peak eluting time for most thermal papers extract was at 5.6 minutes, demonstrating that BPF was present in the thermal papers. The method was applied to quantify the proposed analyses in a variety of samples with excellent results.

This study evaluated the physicochemical characteristics and the production of bioactive compounds of Pereskia aculeata Mill. at different harvest times. Here, we performed a qualitative evaluation of the chemical profile by paper spray mass spectrometry (PSMS), the phenolic acid and flavonoid profile by high-performance liquid chromatography (HPLC), antioxidant activity, total carotenoids, total phenolic compounds, total flavonoids, total anthocyanins, color characteristics, total soluble solids (TSS), total solids (TS), pH, and total titratable acidity (TTA). The chemical profile was not affected, with the exception of 4,5-dimethyl-2,6-octadiene and azelaic acid, which was only identified in the leaves harvested during the winter. The content of four phenolic acids and three flavonoids were analyzed; out of these, no significant amounts of ellagic acid and quercetin were detected. There was no difference in production of bioactive compounds between seasons, reflecting the antioxidant activity, which also did not differ. Brightness, chroma, and leaf pH were the only physicochemical characteristics that did not vary between seasons.

This study evaluated the physicochemical characteristics and the production of bioactive compounds of Pereskia aculeata Mill. at different harvest times. Here, we performed a qualitative evaluation of the chemical profile by paper spray mass spectrometry (PSMS), the phenolic acid and flavonoid profile by high-performance liquid chromatography (HPLC), antioxidant activity, total carotenoids, total phenolic compounds, total flavonoids, total anthocyanins, color characteristics, total soluble solids (TSS), total solids (TS), pH, and total titratable acidity (TTA). The chemical profile was not affected, with the exception of 4,5-dimethyl-2,6-octadiene and azelaic acid, which was only identified in the leaves harvested during the winter. The content of four phenolic acids and three flavonoids were analyzed; out of these, no significant amounts of ellagic acid and quercetin were detected. There was no difference in production of bioactive compounds between seasons, reflecting the antioxidant activity, which also did not differ. Brightness, chroma, and leaf pH were the only physicochemical characteristics that did not vary between seasons. [ABSTRACT FROM AUTHOR]

Abstract: A simple and sensitive high performance liquid chromatographic (HPLC) method with UV detection was developed for the determination of new diethanolamine derivative complexing agents. The quantitation of three complexing agents was accomplished as their Cu(II) complexes and their separation on a reversed phase C18 column using 0.01M tetrabutyl ammoniumhydroxide and methanol as isocratic mobile phase. The limit of detection (LOD) ranges from 0.1 to 2.0mg/l and the method has a wide linear range, from LOD to 150mg/l. The method was successfully applied for the analysis of lake water and wastewater effluent from pulp and paper mill spiked with studied complexing agents. [Copyright &y& Elsevier]

The aim of this study was to establish the provenance of materials used in the manufacturing process of the Kościuszko banknotes. The applied methodology is mostly based on Raman investigations carried out using portable and benchtop instruments. Raman analysis allowed to identify smalt, an optical brightener typically used in paper production in the Netherlands. This result was also confirmed by X‐ray fluorescence spectrometry and scanning electron microscopy coupled with energy dispersive X‐ray spectrometry. The Raman investigation of ink and dyes was supported by Fourier transform infrared spectroscopy analysis and high‐performance liquid chromatography. The detection of typical local dyes such as reseda (Reseda luteola L.) and madder (Rubia tinctorum L.) suggested that the paper was dyed in Poland. The results also indicate the use of charcoal with an admixture of traces of bone black. Finally, a two‐step manufacturing process was identified. The paper was imported and then dyed and printed in Poland, instead of the original assumption, which was that the paper was manufactured and mass dyed abroad and the banknotes were later printed in Poland. [ABSTRACT FROM AUTHOR]

A pre-column derivatization method for the sensitive determination of aliphatic amines using the labeling reagent 1,2-benzo-3,4-dihydrocarbazole-9-ethyl chloroformate (BCEOC) followed by HPLC with fluorescence detection and APCI/MS identification in positive-ion mode has been developed. The chromophore of 2-(9-carbazole)-ethyl chloroformate (CEOC) reagent was replaced by the 1,2-benzo-3,4-dihydrocarbazole functional group, which resulted in a sensitive fluorescence derivatizing reagent, BCEOC, that could easily and quickly label amines. Derivatives were stable enough to be efficiently analyzed by HPLC and showed an intense protonated molecular ion corresponding m/z [M+H]+ with APCI/MS in positive-ion mode. The collision induced dissociation of the protonated molecular ion formed characteristic fragment ions at m/z 264.1, m/z 246.0 and m/z 218.1, corresponding to the cleavages of CH2CH2O-CO, CH2CH2-OCO, and N-CH2CH2O bonds. Studies on derivatization conditions demonstrated that excellent derivatization yields close to 100% were observed with a 3 to 4-fold molar reagent excess in acetonitrile solvent, in the presence of borate buffer (pH 9.0) at 40°C for 10 min. In addition, the detection responses for BCEOC derivatives were compared with those obtained with CEOC and FMOC as labeling reagents. The ratios IBCEOC/ICEOC and IBCEOC/IFMOC were, respectively, 1.40-2.76 and 1.36-2.92 for fluorescence responses (here, I was the relative fluorescence intensity). Separation of the amine derivatives had been optimized on an Eclipse XDB-C8 column. Detection limits calculated from an 0.10 pmol injection, at a signal-to-noise ratio of 3, were 18.65-38.82 fmol (injection volume 10 µL) for fluorescence detection. The relative standard deviations for intraday determination (n=6) of standard amine derivatives (50 pmol) were 0.0063-0.037% for retention times and 3.36-6.93% for peak areas. The mean intra- and inter-assay precision for all amines were <5.4% and 5.8%, respectively. The recoveries of amines ranged from 96 to 113%. Excellent linear responses were observed with correlation coefficients of >0.9994. The established method provided a simple and highly sensitive technique for the quantitative analysis of trace amounts of aliphatic amines from biological and natural environmental samples. [ABSTRACT FROM AUTHOR]

Vitamin A deficiency is the leading cause of preventable blindness in children and increases the risk of disease and death from severe infections. In addition, fat soluble vitamin A and associated retinoids directly regulate the expression of genes involved in fatty acid metabolism. Conventional methods for measuring vitamin A involve venipuncture, centrifugation and refrigeration all of which make measuring vitamin A in nutritional surveys expensive. We aimed to develop a simple and robust system for measurement of retinol (biomarker for vitamin A) using dried blood spot (DBS) samples. Low recoveries and inconsistent results reported by others were found to be due to poor extraction efficiency rather than retinol instability. Maintaining acid conditions during extraction resulted in recoveries >95% with <6.5% of coefficient of variation. Using isocratic high performance liquid chromatography, separation was achieved in <3.5 min. Detector response was linear ( R 2 =0.9939) within a range of 0.05–2 μg/mL, with a limit of quantification of 0.05 μg/mL. Retinol in DBS was shown to be stable (>95%) at room temperature for up to 10 weeks. DBS values for retinol were highly correlated with venous blood samples from 24 healthy subjects ( r =0.9724) and were consistent with results from a commercial laboratory. This simple and reliable method for the determination of vitamin A status should prove particularly valuable for population studies and large clinical trials. [ABSTRACT FROM AUTHOR]

• An instrument-free strategy for semiquantitative naked-eye determination of food colorants (FCs) was developed. • Filter paper-based colorimetric analysis was applied to naked-eye detection of FCs. • FCs indicator papers could be facilely prepared via one-step polycondensation of silane coupling agents onto filter papers. • Visual colorimetric determination of FCs in real-world beverages was achieved with high reliability. A filter paper-based colorimetric strategy for instrument-independent visual detection of artificial food colorants (FCs) was developed in this study. Indicator papers were prepared via the one-step polycondensation of silane coupling agents onto glass microfiber filter papers, and colorimetric cards with a fine one-to-one correspondence between their colors and FCs concentrations were straightforward obtained by the extraction of FCs with indicator papers by virtue of electrostatic interaction and hydrophobic effect. Filter papers post-modified via such a simple way were proved to be of improved binding class selectivity and colorimetric sensitivity, allowing for in-situ colorimetric assay of FCs in an unprecedently wide range of applicable pH (1.0–12.0) with high reliability and fine versatility. Finally, the semiquantitative naked-eye determination of FCs (Allura red, brilliant blue and sunset yellow) in real-world drink samples was experimentally confirmed to be feasible by comparison with the findings of UV–vis absorption spectra, HPLC and mass spectra. [ABSTRACT FROM AUTHOR]

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[Display omitted] • Aflatoxins represent highly toxic secondary metabolites of fungi. • Sample preparation relies on liquid–liquid or solid-phase extraction. • Chromatographic methods ensure advanced purification of analytes. • Optical methods, mass spectrometry and electrochemical techniques are used for detection. • Sensitivity, selectivity, time, procedure complexity, influence the choice of the method. Aflatoxins represent secondary metabolites of fungi, being characterized by a high degree of toxicity. They are classed as poisonous mycotoxins, hence the interest in the control of their level. 20 fungal metabolites compose the class of aflatoxins, that structurally derive from difuranocoumarin. Aspergillus flavus and Aspergillus parasiticus are the main species producing fungal metabolites in cereals, peanuts and animal feeds. Aflatoxins B1, B2, G1, G2, M1 and M2 are the most often encountered. Sample preparation techniques are crucial steps in aflatoxin analysis: they rely on liquid–liquid extraction or solid-phase extraction. Chromatographic methods ensure separation, advanced purification of analytes, which are subsequently quantified through detection techniques. The latter encompass optical methods, mass spectrometry and electroassay. Many analytical methods like ELISA, fluorescence polarization immunoassay, lateral flow immunoassay or PCR impart selectivity by using biorecognition elements: enzymes, antibodies or a DNA sequence. Given the high toxicity and presence of aflatoxins in food and agricultural products, their determination is an essential element in food safety. The analysis method is chosen according to the nature of the sample (type of matrix), the available equipment, the concentration range in which the toxin's level is placed, sensitivity and detection limit, precision, selectivity, required analysis time, personnel training. The present paper provides a comprehensive view, and critically compares the performances of aflatoxin analysis methods, encompassing extraction, separation and detection techniques. [ABSTRACT FROM AUTHOR]

Highlights: [•] Gellan hydrogel is proposed as a new method for wet cleaning of paper artworks. [•] Gellan hydrogel has been used to clean four different paper samples. [•] Every sample has been fully characterized before and after cleaning. [•] For our studies a multitechnique approach has been used. [Copyright &y& Elsevier]

Primary aromatic amines (PAAs) are a class of hazardous substances where many compounds are classified as carcinogen, mutagen, and reproduction toxin (CMR). PAAs can be taken up by dermal exposure. In the polyurethane industry, a valid and trustworthy method for the quantification of PAAs in the presence of isocyanates that could interfere is of great interest, especially on workplaces where a regular contact to PAAs cannot be excluded. The aim of this work is the development, validation, and verification of a novel sampling device to quantify selectively the PAA load on work surfaces. We describe the synthesis of Cell-ßALA-PEMSA analytical papers and their characterization by infrared spectroscopy and thermogravimetric analysis. The recovery of TDA and MDA spiked on these filters is satisfactory. An excellent selectivity of Cell-ßALA-PEMSA papers towards PAAs in the presence of isocyanates of almost 100% was found by wipe tests of amine/isocyanate contaminated surfaces. First positive field tests were achieved at certain areas in a Polyurethane Technical Application Department where surface contamination with PAAs was expected, and the Cell-ßALA-PEMSA analytical papers were superior to an established method of surface sampling. However, recovery of these amines from surfaces shows a large variability, and more work is required to address influencing surface properties. [ABSTRACT FROM AUTHOR]

Alkalophilic Cellulosimicrobium cellulans CKMX1 isolated from mushroom compost is an actinomycete that produces industrially important and environmentally safer thermostable cellulase-free xylanase, which is used in the pulp and paper industry as an alternative to the use of toxic chlorinated compounds. Strain CKMX1 was previously characterized by metabolic fingerprinting, whole-cell fatty acids methyl ester analysis, and 16S rDNA and was found to be C. cellulans CKMX1. Crude enzyme (1027.65 U/g DBP) produced by C. cellulans CKMX1, having pH and temperature optima of 8.0 and 60 °C, respectively, in solid state fermentation of apple pomace, was used in the production of bleached wheat straw pulp. Pretreatment with xylanase at a dose of 5 U/g after pulping decreased pulp kappa points by 1.4 as compared with the control. Prebleaching with a xylanase dose of 5 U/g pulp reduced the chlorine charge by 12.5%, increased the final brightness points by approximately 1.42% ISO, and improved the pulp strength properties. Xylanase could be substituted for alkali extraction in C–Ep–D sequence and used for treating chemically bleached pulp, resulting in bleached pulp with higher strength properties. Modification of bleached pulp with 5 U of enzyme/g increased pulp whiteness and breaking length by 1.03% and 60 m, respectively; decreased tear factor of pulp by 7.29%; increased bulk weight by 3.99%, as compared with the original pulp. Reducing sugars and UV-absorbing lignin-derived compound values were considerably higher in xylanase-treated samples. Cellulosimicrobium cellulans CKMX1 has a potential application in the pulp and paper industries. [ABSTRACT FROM AUTHOR]

To date there have been no reports of methods to determine Tinopal CBS-X. We developed a rapid and simple method to determine the Tinopal CBS-X content in rice noodles and rice papers using HPLC equipped with fluorescence detection. Heating the rice noodles and rice papers to 80°C after adding 75% methanol solution induced the release of Tinopal CBS-X from processed rice products. Tinopal CBS-X was separated using an isocratic mobile phase comprising 50% acetonitrile/water containing 0.4% tetrabutyl ammonium hydrogen sulphate at pH 8.0. The samples suspected to be positive by HPLC analysis were then confirmed by LC-MS/MS analysis. This study also investigated the Tinopal CBS-X content of three rice noodle products and two rice papers. The limits of quantification for rice papers and rice noodles were 1.58 and 1.51 µg kg–1, respectively, and their correlation curves showed good linearity withr2 ≥ 0.9997 and ≥ 0.9998, respectively. Moreover, rice papers had recoveries of 70.3–83.3% with precision ranging from 5.0% to 7.9%, whereas rice noodles had slightly lower recoveries of 63.4–78.7% and precisions of 8.5–11.5%. Only one rice noodle product contained Tinopal CBS-X, at around 2.1 mg kg–1, whereas it was not detected in four other samples. Consequently, Tinopal CBS-X from rice noodles and rice papers can be successfully detected using the developed pre-treatment and ion-pairing HPLC system coupled with fluorescence detection. [ABSTRACT FROM AUTHOR]

Employing high performance liquid chromatography, quantitative estimation of neem compounds, NfC and NC, was carried out in treated insects, Callosobruchus analis, and in contact media, in comparison with an IGR, Diflubenzuron (Dimilin). Adult specimens of Callosobruchus analis were treated with impregnated filter paper mimicking an absorbent surface and treated glass mimicking a non-absorbent surface of grain storing containers. In the case of filter paper impregnation, the recovery of NfC was 4.57 μg/10 μl and 1.28 μg/10 μl in treated insect samples, and 0.71 μg/10 μl and 0.50 μg/10 μl in treated filter paper samples after 24 and 144 h of treatment, respectively. Recovery of NC was 0.71 μg/10 μl after 24 h and no trace was found after 144 h in treated insect samples, whereas treated filter paper samples showed 0.21 μg/10 μl and 0.07 μg/10 μl recovery after 24 and 144 h of treatment, respectively. The recovery of Dimilin was 0.14 μg/10 μl and 0.08 μg/10 μl in treated insect samples, and 0.36 μg/10 μl and 0.14 μg/10 μl in treated filter paper samples after 24 and 144 h of treatment, respectively. In the case of the glass film method, NC treated insects showed 1.42 μg/10 μl and 0.71 μg/10 μl recovery, while the glass rinsed samples showed 0.71 μg/10 μl and 0.07 μg/10 μl recovery after 24 and 144 h of treatment, respectively. Dimilin treated C. analis showed 0.84 μg/10 μl and 0.33 μg/10 μl recovery after 24 and 144 h of treatment, while the glass rinsed samples showed 0.12 μg/10 μl recovery after 24 h and no trace was found after 144 h of treatment. NfC extract showed no significant effect by this method and therefore samples were not analysed. [ABSTRACT FROM AUTHOR]

Abstract: A simple, sensitive, selective and reproducible method based on liquid chromatography was developed for the determination of chloroquine (CQ) and its active plasma metabolite desethylchloroquine (DECQ) in finger-pricked capillary blood spot onto filter paper (DBS) and whole blood samples. Both were separated from the internal standard quinine on a reversed phase C18 column, with the mobile phase consisting of a mixture of 1% diethylamine, acetonitrile and methanol (20:55:25, v:v:v) running at a flow rate of 1.0ml/min. Retention times of QN, DECQ and CQ were 4.5, 5.7 and 6.4min, respectively. Ultraviolet detection was at the wavelength 256nm. Sample preparation was done by extraction with hexane and tert-butyl methyl ether (1:1, v:v). Good precision and accuracy were obtained for both within-day repeatability and day-to-day reproducibility. Limit of quantification (LOQ) for both CQ and DECQ was accepted as 50ng/ml using 80μl DBS sample and 25ng/ml using 150μl whole blood sample. The mean recoveries for CQ, DECQ and internal standard for both whole blood and DBS were between 74 and 87%. The method was successfully applied for a pharmacokinetic study of CQ and DECQ in patients with Plasmodium vivax. Excellence correlation (r =0.997) was observed between the analysis of both CQ and DECQ in paired whole blood and DBS samples. [Copyright &y& Elsevier]

More than 99% radiolabelling of benzyl penicillin with 99mTc was achieved using SnCl2.2H2O as reducing agent. The optimised conditions for the radiolabelling of 99mTc- benzyl penicillin were 200 μg ligand (benzyl penicillin), 25 μg stannous chloride as a reducing agent, pH 6, room temperature and 10 min incubation time. The radiochemical purity, stability and charge on 99mTc labelled benzyl penicillin were determined by paper chromatography, ITLC, HPLC and electrophoresis techniques, respectively. Biodistribution and scintigraphy studies of 99mTc-benzyl penicillin were performed in normal mice and rabbit, respectively. [ABSTRACT FROM AUTHOR]

Mitomycin-C is used for the treatment of different types of tumours. In present work, a reliable method was developed for radiolabeling of Mitomycin-C with Tc for diagnostic purpose. Tc-Mitomycin-C was obtained with radiochemical yield of 100 % by adding 200 µg Mitomycin-C, 1 mL (15 mCi) of pertechnetate in 25 μg SnCl·2HO at pH 7. Labeling efficiency was determined by paper chromatography and ITLC. The charge on Tc-Mitomycin-C was determined by electrophoresis technique. HPLC analyses were performed for the determination of purity of Mitomycin-C and radiochemical purity of labeled complex. Evaluation of Tc-Mitomycin-C, in vitro stability, biodistribution and scintigraphic images in normal mice were performed. [ABSTRACT FROM AUTHOR]

Human biosynthetic insulin is a polypeptide hormone that plays an important and essential role in control of the level of carbohydrate, protein, and fat metabolism in the blood. Human pancreatic insulin was labeled with Tc to form a new radiopharmaceutical with a labeling yield of 99 ± 1% under optimum conditions: 0.1 mL insulin, pH 7, 25 μg stannous chloride, 1 mL (19 mCi) of pertechnetate, room temperature, and 10 min reaction time. The Tc-insulin complex was examined using paper chromatography, ITLC, electrophoresis, and HPLC. In addition, in vitro and in vivo study of Tc-insulin complex was performed at different time intervals. [ABSTRACT FROM AUTHOR]

Preliminary analysis of flavonoid chromatographic migration profiles of endemic/endangered species ofRauvolfiaL from Southern Western Ghats of India were carried out. Paper chromatogram showed maximum separation in the solvent system of forestral. In the paper chromatogram, number of flavonoid spots varied from 9 to 12 in the five taxa studied. The main aglycones detected in high performance liquid chromatography (HPLC) analysis were flavones apigenin and luteolin, flavonol kaempferol, myricetin, quercetin and anthocyanidins such as delphinidin and cyanidin. Flavonol Quercetin was detected in all the five species ofRauvolfiagiving a chemotaxonomic significance to its presence at the generic level. The two speciesRauvolfia serpentinaandRauvolfia tetraphyllacould be regarded as the most primitive in the evolutionary line with respect to the flavonoid pattern.Rauvolfia densiflorahas the most advanced pattern of flavonoids. The dendrogram generated by unweighted pair group method with arithmetic average (UPGMA) cluster analysis of chemo metric data showed a clear grouping of five species in three clusters. Flavonoid profiles were efficiently used for the identification ofRauvolfia beddomei, which due to morphological similarity, was erroneously suspected to be the medicinally significant speciesRauvolfia micrantha. Flavonoid profiling using paper chromatography, in the solvent system of forestral could suggest an easy and quick procedure for identifying adulteration by substitution inRauvolfiaspecies. [ABSTRACT FROM AUTHOR]

Timely access to topic-relevant datasets is of paramount importance for the development of any successful strategy (food waste reduction strategy), since datasets illuminate opportunities, challenges and development paths. PhInd is the first comprehensive database on polyphenol content in plant-based by-products from the agri-food sector or the wastewater sector and was developed using peer-reviewed papers published in the period of 2015–2021. In total, >450 scientific manuscripts and >6000 compound entries were included. Database inclusion criteria were polyphenol contents = determined using HPLC/UHPLC quantitative methods. PhInd can be explored through several criteria which are either 'open' or checkboxes. Criteria are given in subsections: (a) plant source; (b) by-product industrial processing; (c) pre-treatment of by-products before the isolation of polyphenols; and (d) the extraction step of polyphenols. Database search results could be explored on the website directly or by downloading Excel files and graphs. This unique database content is beneficial to stakeholders—the food industry, academia, government and citizens. [ABSTRACT FROM AUTHOR]

AbstractPsychoactive substances pose significant challenges and dangers to society due to their impact on perception, mood, and behavior, leading to health and life disturbances. The consumption of these substances is largely influenced by their legal status, cultural norms, and religious beliefs. Continuous development and chemical modifications of psychoactive substances complicate their control, detection, and determination in the human body. This paper addresses the terminological distinctions between psychoactive and psychotropic substances and drugs. It provides a comprehensive review of analytical methods used to identify and quantify 25 psychoactive substances in various biological matrices, including blood, urine, saliva, hair, and nails. The analysis categorizes these substances into four primary groups: stimulants, neuroleptics, depressants, and hallucinogens. The study specifically focuses on chromatographic and spectrophotometric methods, as well as other novel analytical techniques. Methodology includes a review of scientific articles containing validation studies of these methods and innovative approaches to psychoactive substance determination. Articles were sourced from the PubMed database, with most research originating from the twenty first century. The paper discusses the limits of detection and quantitation for each method, along with current trends and challenges in the analytical determination of evolving psychoactive substances. [ABSTRACT FROM AUTHOR]

Research was carried out on the isolation of betulin and suberin from the debarking waste of the Arkhangelsk Pulp and Paper Mill pulpwood, ground on an abrasive crusher. Betulin was extracted from various fractions of technical bark with 86% ethanol under exposure to microwave electromagnetic field (EMF) (microwave extraction). Suberin was isolated from the extracted bark by hydrolysis with an aqueous KOH solution under microwave heating conditions as well. The maximum yields of betulin and suberin were achieved when using coarse bark fractions (3–4.5 mm), which were essentially crushed birch bark. The resulting products were identified by IR and NMR spectroscopy and by gas chromatography combined with mass spectrometry (GC/MS). The contents of the components in the bark extracts were determined by HPLC analysis. The extractives were dominated by triterpenoid betulinol (70–72%), with betulinic acid, lupeol, and erythrodiol being present less abundantly. Fatty, dibasic carboxylic acids, and hydroxy acids, dominated by 2-hydroxydecanedioic (2-hydroxysebacic) acid, were identified among the suberin monomers. The content of ferulic acid, a natural antioxidant, was determined in the product from different fractions of the bark (from 2.65 to 11.27 g/kg). The suberin obtained from fine bark fractions differs in the composition from that obtained from coarse fractions. Ribofuranose and xylose were detected in the product obtained from the 1–2 mm bark fraction but were absent in that from the 2–3 mm fraction; lanosterol was present in the suberin from fine fraction of the bark, and cycloartenol, in that from coarse fraction. [ABSTRACT FROM AUTHOR]

In this study, reversed-phase HPLC procedure was conducted for the synchronized amount of water-soluble such vitamins as thiamine (B1), riboflavin (B2), niacin (B3) pyridoxine (B6), and cobalamin (B12) in four Meat Based Ethnic Foods (MBEF) of Turkey. In this paper, we investigated MBEF Kelle-Paça, Arnavut Ciğeri, Erzurum Cağ Kebabı, Keşkek respectively. In this paper, rapid and a simple method was constructed for the determination of some water-soluble vitamins (B1, B2, B3, B4, B12), by High-performance liquid chromatography. The B2, B3, B4, B6, and B12 content was determined high in Arnavut Ciğeri 498.68 µg/portion, 2.9857 µg/portion, 24.607 µg/portion, 2.2149 µg/portion, 178.36 µg/portion respectively a significant amount B6 ingredient in Erzurum Cağ Kebab 1.5320 µg/portion. The results of investigation showed that among these meat based ethnic foods are rich sources of vitamins Arnavut Ciğeri. In the food sector, the successful implementation of a simple, low-cost, and time-efficient approach is used to determine these vitamins. We have indicated our meat based ethnic foods are healthy and available. And also, the most commonly used method in the determination of vitamins of the B-groups is RP-HPLC is most suitable procedure. The procedures validation indicated that it is extremely sensitive, selective, and linear. [ABSTRACT FROM AUTHOR]

Formaldehyde, the simplest molecule of the aldehyde group, is a gaseous compound at room temperature and pressure, is colorless, and has a strong, pungent odor. It is soluble in water, ethanol, and diethyl ether and is used in solution or polymerized form. Its maximum daily dosage established by the EPA is 0.2 μg g−1 of body weight whereas that established by the WHO is between 1.5 and 14 mg g−1: it is in category 1A of carcinogens by IARC. From an analytical point of view, formaldehyde is traditionally analyzed by HPLC with UV-Vis detection. Nowadays, the need to analyze this compound quickly and in situ is increasing. This work proposes a critical review of methods for analyzing formaldehyde in food using sensing methods. A search carried out on the Scopus database documented more than 50 papers published in the last 5 years. The increase in interest in the recognition of the presence of formaldehyde in food has occurred in recent years, above all due to an awareness of the damage it can cause to human health. This paper focuses on some new sensors by analyzing their performance and comparing them with various no-sensing methods but focusing on the determination of formaldehyde in food products. The sensors reported are of various types, but they all share a good LOD, good accuracy, and a reduced analysis time. Some of them are also biodegradable and others have a very low cost, many are portable and easy to use, therefore usable for the recognition of food adulterations on site. [ABSTRACT FROM AUTHOR]

A power transformer outage has a dramatic financial consequence not only for electric power systems utilities but also for interconnected customers. The service reliability of this important asset largely depends upon the condition of the oil-paper insulation. Therefore, by keeping the qualities of oil-paper insulation system in pristine condition, the maintenance planners can reduce the decline rate of internal faults. Accurate diagnostic methods for analyzing the condition of transformers are therefore essential. Currently, there are various electrical and physicochemical diagnostic techniques available for insulation condition monitoring of power transformers. This paper is aimed at the description, analysis and interpretation of modern physicochemical diagnostics techniques for assessing insulation condition in aged transformers. Since fields and laboratory experiences have shown that transformer oil contains about 70% of diagnostic information, the physicochemical analyses of oil samples can therefore be extremely useful in monitoring the condition of power transformers.

Ibrutinib (IBR) is a tyrosine kinase inhibitor investigated for treating solid and non-solid tumors. Considering the advantages that a topical application of IBR could generate in terms of dose reduction and side effects in skin cancer treatment, this paper presents a simple and selective HPLC method for determining IBR concentration in in vitro skin permeation studies to support the development of topical formulations. The method uses a reversed-phase C18 column and a mobile phase composed of acetonitrile and 0.01 mol/L phosphoric acid at pH 3.5 (35:65 v/v), flowing at 1.0 mL/min. The oven temperature was set at 35 °C, the injection volume was 20 μL, and UV drug detection was performed at 259 nm. The validation procedure certified that this method was selective for IBR determination even when extracted from human or porcine skin matrices. The method was linear over a range of 0.2 to 15.0 μg/mL, precise, robust, and accurate, with recovery rates from the skin layers higher than 89.5 ± 5.9% for the porcine skin and higher than 92.0 ± 0.2% for the human skin. The limits of detection and quantification were 0.01 and 0.02 μg/mL, respectively. The method showed, therefore, to be adequate for use in further skin permeation studies employing IBR topical formulations. [ABSTRACT FROM AUTHOR]

Objective: The objective of this paper was to assess the airborne mold contamination, secondary metabolite profiles, and cytotoxicity of the dominant fungal species isolated from the air in selected rooms at a Zoological Garden. Materials and methods: Fungal concentrations were measured with MAS-100 air samplers. The collected airborne fungi were identified using a combination of morphological and molecular methods. The cytotoxicity of 84 strains belonging to two Penicillium and Aspergillus genera was determined using the quantitative colorimetric MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium salt) assay. The mycotoxins were detected using high-performance liquid chromatography (HPLC) with a mass spectrometry detector. Results: The ITS gene was amplified and sequenced to identify the 132 species. For mycotoxicological and cytotoxicity analyses, 52 Penicillium isolates and 32 Aspergillus representatives were selected. Cytotoxicity was confirmed in 97.6% of cases analyzed. Using the LC-MS/MS method, 42 out of 84 strains produced at least one of the following toxins: ochratoxin A, ochratoxin B, patulin, gliotoxin, roquefortine C, griseofulvin, sterigmatocystin, fumonisin B2, moniliformin, and mycophenolic acid. Conclusions: Analytical methods for assessing the presence of mycotoxins in fungal isolates collected directly from the air have proven to be an effective tool. Our research provides new information on the occurrence of potentially toxin-producing molds within a zoo. [ABSTRACT FROM AUTHOR]

Extra virgin olive oil is one of the healthiest vegetable oils and it is the best source of fats in the Mediterranean Diet. Olive tree cultivation and olive oil consumption spread all over the world and since extra virgin olive oil is also one of the most expensive oils, often undergoes fraudulent practices by mixing it with lower grade oils. Improved knowledge of olive oils and technology may give rise to a frequent extra virgin counterfeiting by mixing authentic extra virgin olive oils with the so-called soft- or mild-deodorised oils: these are virgin oils, deodorised in a soft way to distillate unpleasant compounds so that oils can be blended with real extra virgin oils and be illegally sold as if they were fully authentic. The aim of this paper is to describe an approach that takes into consideration the ultraviolet absorbency of each triglyceride in soft-deodorised oils or micro- or ultrafiltered oils and their blends with authentic extra virgin oils. Further data elaboration by principal component analysis allowed us to clearly distinguish false extra virgin oils from authentic. Furthermore, chromatographic separation enables us to calculate the ECN42 without performing a new HPLC separation according to the Official method, as required by the law in force. [ABSTRACT FROM AUTHOR]

Dried blood spots have been used as alternatives to traditional plasma and serum samples. We have now developed new devices, named volumetric absorptive paper disc (VAPD) and mini-disc (VAPDmini), to collect accurate volumes of dried blood spots in a simple manner and without the need for additional instruments. VAPD consists of a filter paper disc and a filter paper sheet with holes slightly larger than the disc. The disc is fixed in one such hole without direct contact with the filter sheet. VAPDmini is a scaled-down version of the same device. When several drops of whole blood are applied, the disc becomes saturated and any excess sample is absorbed by the surrounding filter sheet. Accuracy and precision of sampling were assessed by determining the levels of clozapine and its metabolites as target analytes by liquid-liquid extraction and high-performance liquid chromatography with coulometric detection. In addition, differences in analyte recovery were within ±15% for all analytes in samples with 30–60% hematocrit, suggesting that VAPD and VAPDmini are insensitive to hematocrit for the analytes tested. The devices were also validated for analyte concentrations in the range 50–1000 ng/mL, and the limit of detection and lower limit of quantification were 5–17 ng/mL and 15–51 ng/mL, respectively. Intra- and inter-day precision ranged from 3% to 13%, whereas accuracy ranged from a −14% to 12% bias. Analytes were stable in the devices for at least 2 weeks at room temperature. Collectively, these results indicate that sampling using VAPD and VAPDmini is comparable to conventional hole punch sampling of entire dried blood spots, even for samples obtained from patients treated with clozapine. Importantly, the devices were also found to be suitable for sample self-collection. [ABSTRACT FROM AUTHOR]

A reliable reversed-phase high performance liquid chromatographic (HPLC) method has been developed for simultaneous determination of p-benzoquinone dioxime (BQD) and its related impurity p-nitrosophenol (NSP). Separation was achieved on a Kromasil C 18 column by using methanol-water-NH 4 Ac-NH 3 solution (pH=7.0, 50 mM) (30/50/20, v/v/v) as the mobile phase, and detection was operated by UV absorption at a wavelength of 305 nm. The method was seen to have good linearity, accuracy, and precision for the concentration range and to be an attractive choice for the quality control of BQD for industrial use. Moreover, the HPLC-UV-vis fingerprint of BQD has been established, and successfully applied to quality control of industrial BQD in laboratories of some rubber factories in China. Chromatographic fingerprints of intermediates would become an effective strategy for accelerating the progress of fine chemical industry. [ABSTRACT FROM AUTHOR]

Kava is the traditional intoxicating beverage of the Pacific with mild sedative and muscle relaxant effects, which are attributed to a group of compounds known as kavalactones. This paper aims to evaluate the quality of kava sold in the local markets of Fiji through the quantification of the six major kavalactones in kava root bundles and powdered kava packages using ethanolic extracts and HPLC. It was found in this work that kava root bundles contain mainly noble kava roots with a total kavalactone content of 8–13%; kavain had the highest concentration among kavalactones and kavain, methysticin, and yangonin together represented 69–71% of the total kavalactone content. Adulteration via mixing noble kava roots with those of non-noble kava with a relatively high dihydrokavain and dihydromethysticin content has also been observed. Powdered kava products were found to contain lower amounts of kavalactones (3–5%) with a less favorable kavalactone profile than those of root bundles, possibly due to mixing roots, rhizomes, and/or basal stems. The findings of this work, namely the variation in kavalactone content and profile in marketed products, indicate the need for rigorous quality control and quality indicators on kava commodities. Suggestions to include quantitative measures in the previously proposed chemical standardization code are also presented. [ABSTRACT FROM AUTHOR]

Some parts of agro-wastes (pomace meal) are used for animal food containing variability in composition (proteins, dietary fibres, carbohydrates, polyphenols, minerals). Paper aim was to evaluate some nutraceutical bioactive compounds from pomace meal for use as animal feed additives. Studied meals are pomace obtained from solid remains of grapes and sea buckthorn after juice pressing, as well as flaxseed and rapeseed after oil pressing. HPLC methods were used to determine some carbohydrates (glucose, fructose, sucrose, maltose), organic acids (oxalic, citric, tartaric, malic), flavonoids (catechin, epicatechin, rutin, quercetin, luteolin) and phenolic acids (gallic, vanillic, caffeic, p-coumaric, ferulic). The content of total polyphenolic compounds and the antioxidant activity (DPPH and ABTS assays) of the pomace meals were evaluated by spectrophotometry. The results obtained show that the carbohydrates quantities (mg/100 g) in pomace meals were between 2943.31 (grapeseed) and 3210.11 (rapeseed). Sea buckthorn contains the most important amount of total organic acids of 8078.89 mg/100 g. Also, the highest quantities (mg/100 g) of total polyphenolic compounds were found in grapeseed (10789) and flaxseed (8537), respectively. These findings indicate a good source of carbohydrates, organic acids and polyphenols (phenolic acids and flavonoids) therefore these meals can be used as animal feed additives. [ABSTRACT FROM AUTHOR]

This review highlights the advantages of high-precision liquid chromatography with an electrochemical detector (HPLC-ECD) in detecting and quantifying biological samples obtained through intracerebral microdialysis, specifically the serotonergic and dopaminergic systems: Serotonin (5-HT), 5-hydroxyindolacetic acid (5-HIAA), 3,4-dihydroxyphenylacetic acid (DOPAC), dopamine (DA), 3-metoxytryptamin (3-MT) and homovanillic acid (HVA). Recognized for its speed and selectivity, HPLC enables direct analysis of intracerebral microdialysis samples without complex derivatization. Various chromatographic methods, including reverse phase (RP), are explored for neurotransmitters (NTs) and metabolites separation. Electrochemical detector (ECD), particularly with glassy carbon (GC) electrodes, is emphasized for its simplicity and sensitivity, aimed at enhancing reproducibility through optimization strategies such as modified electrode materials. This paper underscores the determination of limits of detection (LOD) and quantification (LOQ) and the linear range (L.R.) showcasing the potential for real-time monitoring of compounds concentrations. A non-exhaustive compilation of literature values for LOD, LOQ, and L.R. from recent publications is included. [ABSTRACT FROM AUTHOR]

Currently, natural plant extracts, which include biologically active substances, are increasingly used to produce medicines and cosmetics. In connection with the dangers of a radioecological crisis, special attention is paid to finding ways to protect against the effects of chronic exposure to low-intensity ionizing radiation in natural conditions. Currently, there is no ideal and safe radioprotective agent available, and we are seeing a great effort to find these agents from natural sources. Poplar extract is possible for use as a radioprotective shield from γ-radiation. Samples of protective screens were made from poplar extract on paper and showed a significant radioprotective effect. Phenolic compounds and flavonoids are widely present in plants as a second metabolite and are considered for research depending on their benefits for human health, healing and preventing many disorders. The main biologically active properties of flavonoids include antioxidant, anti-inflammatory, antitumor, rejuvenating, antibacterial and viral, neuroprotective and radioprotective action. The aim of this work was - the study of Flavonoids in an extract obtained from poplar buds and the possibility of their use for protection against radiation. Materials and methods. The object of research is the vegetative organs of poplar (buds). In the process of work, experimental studies were carried out on the extraction and separation of natural compounds, identification of flavonoids, and study of the chemical composition of biologically active complexes of poplar and preparations based on them. Research results. Data from these studies provide the identification of flavonoids by spectroscopy and quantification of flavonoids in poplar bud extract and can contribute to the optimization of radioprotection procedures. The main components found in the poplar buds dry extract are 2',6'-dihydroxy-4'-methoxychalcone - are 2',6'-dihydroxy-4'-methoxychalcone - 2.67 %, 3,4-dihydro-2',6'-dihydroxy-4'-methoxychalcone - 2.33 %, pinobaxin - 1.91 %, chrysin - 0.76 %, pinostrobin - 0.04 %, pinocembrin - 0.61 %, tectochrysin - 0.54 % and galangin - 0.18 % of dry material. The results showed that the power of the penetrating radiation decreases with increasing the thickness of the protective screen. The power of penetrating radiation decreased from 78 % at the layer of 0.5 mm to 10 % at 3 mm layer thickness. Further increasing the thickness of the protective screen (>3 mm), doesn't affect the dose rate. Conclusions. The composition of the poplar buds' ethanol extract was investigated. Samples of protective screens made on the basis of poplar extract on paper showed a significant radioprotective effect on low-intensity ionizing radiation. [ABSTRACT FROM AUTHOR]

Chitosan is a linear biopolymer composed of D-glucosamine and N-acetylglucosamine units. The percentage of D-glucosamine in the polymeric chain can vary from one sample to another and is expressed as the degree of deacetylation (DDA). Since this parameter has an impact on many properties, its determination is often critical, and potentiometric titration is a common analytical technique to measure the DDA. Cross-linking with glutaraldehyde is one of the most explored modifications of chitosan; however, the determination of the DDA for the resulting reticulated chitosan resins can be challenging. In this paper, we report a new, rapid, and efficient method to determine the DDA of glutaraldehyde-cross-linked chitosan resins via HPLC. This method relies on the use of 2,4-dinitrophenylhydrazine (DNPH) as a derivatizing agent to measure the level of reticulation of the polymer (LR) after the reticulation step. In this study, we prepare three calibration curves (with an R2 value over 0.92) for three series of reticulated polymers covering a large range of reticulation levels to demonstrate that a correlation can be established between the LR established via HPLC and the DDA obtained via titration. The polymers are derived from three different chitosan starting materials. These standard calibration curves are now used on a routine basis in our lab, and the HPLC method has allowed us to change our DDA analysis time from 20 h to 5 min. [ABSTRACT FROM AUTHOR]