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Background: Wastewater can contain a complex mixture of organic micropollutants, with both chemical analysis and effect-based methods needed to identify relevant micropollutants and detect mixture effects. Solid-phase extraction (SPE) is commonly used to enrich micropollutants prior to analysis. While the recovery and stability of individual micropollutants by SPE has been well studied, few studies have optimized SPE for effect-based methods. The aim of the current study was to develop and evaluate two standard operating procedures (SOPs) for the enrichment of micropollutants in preparation for chemical analysis and bioanalysis, one covering a broad range of chemicals and the other selective for estrogenic chemicals. Results: Pristine surface water spiked with > 600 micropollutants was used to develop a generic extraction method for micropollutants with a wide range of physiochemical properties, while water spiked with estrogenic chemicals was used to identify a selective extraction method. Three different SPE sorbents were tested, with recoveries of individual chemicals and effect in assays indicative of mutagenicity, estrogenic activity, and fish embryo toxicity assessed. The sorbent HRX at pH 7 was selected for the generic extraction method as it showed the best recovery of both individual chemicals and effect in the bioassays. The sorbent HLB at pH 3 showed optimal recovery of estrogenic chemicals and estrogenic activity. The two optimal SPE methods were applied to spiked and unspiked wastewater effluents, with the concentrations of detected chemicals and observed effects similar to those of previous studies. The long-term storage of both extracts and SPE cartridges for estrogens and estrogenic activity after extraction with the HRX and HLB methods were evaluated, with estrogenic effectiveness close to 100% after 112 days when HLB was used. Conclusions: HRX is recommended for generic extraction, while HLB is optimal for the selective extraction of estrogenic micropollutants. However, if a laboratory only wants to use a single SPE sorbent, HLB can be used for both generic and selective extraction as it yielded similar chemical and effect recovery as HRX for a wide range of micropollutants. This paper is supplemented by the final SOP that includes a variant for generic extraction and one for the extraction of estrogenic chemicals. [ABSTRACT FROM AUTHOR]

Food analysis plays an important role in preserving the integrity and quality of food. Despite these noble goals, most official methods for the analysis of nutrients (vitamins, carotenoids, etc.) antioxidants (polyphenols, etc.), and contaminants (pesticides, veterinary drugs, mycotoxins etc.) still rely on time-consuming, complex, and polluting procedures of sample preparation. To solve this discrepancy, the scientific community has frantically been working to make extraction procedures faster and safer, resorting to miniaturization, automation, low-energy consumption, and solvents/sorbents from renewable resources. This review provides an overview of the most sustainable extraction methods in food analysis, developed over the last ten years (2014–2024), including relevant examples of both liquid phase and sorbent-based techniques. Particular emphasis is placed on solutions aimed at improving the method sustainability such as smart devices, neoteric solvents, and composite sorbents, discussing the latest advancements and future trends in this sector.

Solid-phase analytical derivatization is a versatile sample preparation technique that enhances analysis accuracy, efficiency, reproducibility, and sensitivity. The technique combines the advantages of analytical derivatization and solid-phase extraction, providing a versatile approach for analysing analytes with various functional groups in complex matrices. Analytical derivatization is a technique used for functional group analysis that involves modifying the structure of an analyte to enhance sensitivity and specificity. Solid-phase analytical derivatization is a one-pot procedure that combines analytical derivatization and extraction. In the presence of acids, it can derivatize phenols, carboxylic acids, and other analytes. Furthermore, solid-phase analytical derivatization increases the reaction rate of carbonyl compounds, making it easier to extract aldehydes and ketones rapidly. This technique utilises electrophoresis, chromophores, fluorophores, and functional groups for detection and extraction. It initially began as a batch procedure but has now developed into an automated, microextraction, and derivatization method. Solid-phase analytical derivatization is highly efficient due to the significant excess of the derivatizing reagent relative to the analyte, along with the pre-impregnation of derivatizing reagents, which can speed up the process compared to traditional solution-based derivatization. This tutorial aims to provide detailed insights into the practical aspects of implementing solid-phase analytical derivatization in analytical method development and discuss the prospects and future trends.

In this work, is proposed an analytical method for the determination of nickel in natural water and sediment samples using solid-phase extraction with a mini-column of bamboo fibres modified with 5-Br-PADAP and determination by flame atomic absorption spectrometry. Applying the characterisation techniques of fresh bamboo fibre aimed to define the morphology of the fibre and its physical characteristics. Turning to the optimisation of the variables for the adsorptive process of nickel. The system allows the determination of nickel with a limit of detection (LOD) of 0.75 μg L−1 and a limit of quantitation (LOQ) of 2.50 μg L−1. The precision was expressed as a relative standard deviation (RSD) of 3.4 and 3.8% for a nickel concentration of 20.0 and 50.0 μg L−1 respectively. The value of 78.0 was determined as the value for the enrichment factor. The accuracy was confirmed with spike tests with recuperations varying from 91% to 106% and 93% to 104% for water and sediment samples, respectively, and by comparison with the certified sample. The procedure was applied for nickel determination in natural water and sediment samples. The achieved concentrations varied from 4.0–53.2 and 3.7–55.8 µg L−1 for water and sediment samples, respectively. [ABSTRACT FROM AUTHOR]

Accurate quantitative analysis of trace analytes in a complicated matrix is a challenge in modern analytical chemistry. An appropriate analytical method is considered to be one of the most common gaps during the whole process. In this study, a green and efficient strategy based on miniaturized matrix solid‐phase dispersion and solid‐phase extraction combined with capillary electrophoresis was first proposed for extracting, purifying and determining target analytes from complicated matrix, using Wubi Shanyao Pill as an example. In detail, 60 mg of samples were dispersed on MCM‐48 to obtain high yields of analytes, then the extract was purified with a solid‐phase extraction cartridge. Finally, four analytes in the purified sample solution were determined by capillary electrophoresis. The parameters affecting the extraction efficiency of matrix solid‐phase dispersion, purification efficiency of solid‐phase extraction and separation effect of capillary electrophoresis were investigated. Under the optimized conditions, all analytes demonstrated satisfactory linearity (R2>0.9983). What's more, the superior green potential of the developed method for the determination of complex samples was confirmed by the Analytical GREEnness Metric Approach. The established method was successfully applied in the accurate determination of target analytes in Wubi Shanyao Pill and thus provided reliable, sensitive, and efficient strategy support for its quality control. [ABSTRACT FROM AUTHOR]

Here, we propose a concept of immobilized sorption-colorimetric microprobes for preconcentration and sensing of colored analytical forms. Individual particles of sorbents distributed over a small area of 1 mm × 1 mm and attached to an easy-to-made strip with an adhesive layer were considered as the probes producing colorimetric responses through preconcentration of colored analytical forms. These responses were then directly recorded with a scanner at 1200 dpi, separated from a background, and processed to obtain information about the amounts of analytes. The food dyes Fast Green FCF, and Ponceau-4R were used as the proof-of-concept colored analytes. The microprobes based on silica modified with quaternary ammonium bases and on alumina were studied. Some features of the analytes' adsorption by the probes and their scanometric sensing were found. It was shown that the proposed method is applicable for the determination of 1–7 mg L−1 of the dyes. [ABSTRACT FROM AUTHOR]

Abstract In the present research, brewed tea waste (BTW) was utilized as a green, low-priced, and abundant adsorbent for separation/preconcentration of Cd(II) ions through solid-phase extraction method from water and foods for the first time. BTW was applied as a natural adsorbent, without using any chelating agent to bind Cd(II) ions or any chemical reagent for its modification. A three-layer artificial neural network model using backpropagation algorithm was utilized to explicate a prediction model for the extraction performance of Cd(II) ions by selecting the input parameters as solution pH, quantity of BTW, sample volume, eluent concentration and volume, and equilibrium time for desorption. The preconcentration factor, relative standard deviation, and detection limit were attained as 100, 3.03%, and 0.56 µg L−1, respectively. It was decided that the Langmuir isotherm model is acceptable to characterize the retention of Cd(II) ions on BTW. This result pointed out that the active binding sites on the BTW surface are homogeneously distributed. Adsorption capacity of BTW was achieved as 41.5 mg g−1 which is higher than several expensive and difficult-to-prepare adsorbents. Adsorption kinetics was elucidated by pseudo-second order kinetic model. After confirmed the accuracy of the method with spike/recovery studies, it was employed for Cd(II) determination in water (stream and sea water) and food (eggplant, lettuce, parsley, apple, and apricot) samples with high accuracy. The inferences of the study proved that the BTW offers a magnificent application prospect in the extraction of Cd(II) ions.

A remarkable growth was noticed in the development of molecularly imprinted polymers (MIPs), which have used as efficient synthetic antibodies that contain selective cavities to the target molecule. Hereunder, a novel strategy using MIP as a sorbent in solid-phase extraction was coupled to a fluorescence method for ellagic acid (EA) purification and immediate detection. The synthesis of magnetic-MIP (MMIP) using a rapid and green ultrasound technology was assessed by central composite design to determine the optimal polymerization conditions for a high-imprinting polymer. The MMIP was characterized by Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, and scanning/transmission electron microscopy, which accurately confirmed the functional, magnetic, and morphological features of MMIP. The prepared MMIP was demonstrated to be selective for EA compared to many similar phenols. The spectrofluorometric method showed a linear range from 0.05 to 2 μg·mL−1 of EA, and the limits of detection (LOD) and quantification (LOQ) were 0.005 and 0.02 μg·mL−1, respectively. Besides, the novel proposed smartphone method using the ultraviolet lamp as the excitation source presented a linear range from 0.2 to 4 μg·mL−1, a LOQ of 0.2 μg·mL−1, and a LOD of 0.07 μg.mL−1. The proposed strategy revealed high efficiency in the extraction and detection of EA in grape, redberry, and green tea. Effectively, the calculated recoveries were ranging from 80 to 102% with low values of relative standard deviation (

Abstract The adsorption efficiency of Pb(II) and Cd(II) from aqueous solutions on m-phenylenediamine-modified Amberlite XAD-4 resin was investigated. The effects of pH, adsorbent amount, initial metal concentration, eluent type and volume and flow rate on the retention of the metal ions have been studied on column studies. The optimum parameters were determined as pH 5, concentration 10 mg/L, stirring time 30 min and 0.2 g adsorbent amount and flow rate 2.5 mL/min for a quantitative adsorption. Sorption data were interpreted in terms of Langmuir and Freundlich equations, and both models were found to be fully appropriate. Each column can be used up to 10 sequential analyses without considerable change. The results indicate high metal adsorption capacity and satisfactory recovery of Pb(II) and Cd(II).

A method for multiclass determination of β-lactam antibiotics in human urine by solid-phase extraction (SPE) prior to quantification by hydrophilic interaction liquid chromatography (HILIC) was developed. Four cephalosporins, one carbapenem and four penicillins were selected among the most prescribed β-lactam drugs. A HILIC column – silica-linked zwitterionic sulfobetaine groups – proved to be valuable for analysis of these three classes of highly hydrophilic compounds, with suitable capacity factors, peak shape and resolution gained by proper selection of the chromatographic conditions. Sample extraction has been performed on Strata™-X. The quick SPE procedure entirely developed in urine successfully combined sample clean-up, avoiding protein precipitation before extraction, with recovery higher than 66% (interday RSD < 15%, n = 5), and method quantification limits in urine in the range 1–4 µg mL−1. Selectivity has been proven on blank urine samples, also in presence of several non-target pharmaceuticals, and the method was applied to the analysis of samples from four patients under β-lactams therapy.

Surface-enhanced Raman spectroscopy (SERS) is a powerful method in analytical chemistry, but its application in real-life medical settings has been limited due to technical challenges. In this work, we introduce an innovative approach that is meant to advance the automation of microfluidics SERS to improve reproducibility and label-free quantification of two widely used therapeutic drugs, methotrexate (MTX) and lamotrigine (LTG), in human serum. Our methodology involves a miniaturized solid-phase extraction (μ-SPE) method coupled to a centrifugal microfluidics disc with incorporated SERS substrates (CD-SERS). The CD-SERS platform enables simultaneous controlled sample wetting and accurate SERS mapping. Together with the assay we implemented a machine learning method based on Partial Least Squares Regression (PLSR) for robust data analysis and drug quantification. The results indicate that combining μ-SPE with CD-SERS (μ-SPE to CD-SERS) led to a substantial improvement in the signal-to-noise ratio compared to combining CD-SERS with ultrafiltration or protein precipitation. The PLSR model enabled us to obtain the limit of detection and quantification for MTX as 2.90 and 8.92 μM, respectively, and for LTG as 10.76 and 32.29 μM. We also validated our μ-SPE to CD-SERS method for MTX against HPLC and immunoassay (p-value <0.05), using patient samples undergoing MTX therapy. In addition, we achieved a satisfactory recovery rate (80%) for LTG when quantifying it in patient samples. Our results show the potential of this newly developed approach as a strategy for therapeutic drugs in point-of-care clinical settings and highlight the benefits of automating label-free SERS assays. [ABSTRACT FROM AUTHOR]

[Display omitted] • Natural kapok fiber without any pretreatment was directly used as a SPE sorbent. • In-syringe extraction device was adeptly crafted for streamlined usability. • Extraction was completed in under 3 min with simple pull–push operations. • By coupling HPLC-UV, six antidepressants in biofluids were effectively quantified. • Five greenness metrics all indicated the method's excellent greenness. Effective antidepressant monitoring is crucial for safe treatment, with liquid chromatography being the primary detection method. Due to the complexity of biofluids, meticulous sample preparation is vital to remove interferences and concentrate analytes. In this study, a novel solid-phase extraction method utilizing unprocessed kapok fiber (KF) as an eco-friendly and efficient sorbent, ingeniously incorporated within an in-syringe device for the extraction of antidepressants from biofluids was introduced. The extraction process displayed several advantages, including simplicity and rapidity (less than 3 min with minimal manual intervention), as well as the potential for automation, which represents significant advancements in sample preparation techniques. The method demonstrated excellent analytical performance when coupled with high-performance liquid chromatography-ultraviolet detection, achieving good linearity (R2 ≥ 0.991), excellent relative recovery (92.6–107.5 %), high precision in intraday and interday analyses (RSDs within 0.8–6.0 % and 1.2–7.9 %, respectively), and good sensitivity with limits of quantification between 5–10 ng/mL. Notably, given the use of a renewable and biodegradable material with KF, and a low-toxicity desorption solvent with ethanol, the developed method stands out for its environmental sustainability, aligning with green analytical chemistry principles. Its application to real biological samples validates its efficacy as a rapid and reliable tool for clinical and forensic monitoring of antidepressants. Moreover, the low cost of this method facilitated by the economical nature of KF and the reusability of syringes further enhances its practicability. This study presents a unique approach by employing natural and renewable KF as adsorbents, thereby eliminating the need for complex material synthesis and making a pioneering contribution to the field of analytical chemistry for drug analysis in complex matrices. [ABSTRACT FROM AUTHOR]

Our food preparation and eating habits have gradually changed due to the pace of business life. Which have paved the way for the rapid development of ready-made food and plastic production industries. Various packets used for storing and selling ready-made foods and disposable plastic products contain Bisphenol A (BPA) which is very dangerous for health. This substance which can be transferred to the food not only acts like a hormone in the human body but also causes various diseases such as cancer, diabetes and obesity. The sensitive determination of this substance has gained importance in foods, human body fluids and tissues. For this purpose, researchers have developed various chromatographic, electrochemical and spectroscopic methods for BPA determination. In this review, the purpose of use, usage areas, exposure routes of BPA and its harms, methods developed to determine substance in question and pros and cons of various methods are discussed.

Chiral resolution of binaphthylamine is often a toilful conundrum in the field of analytical chemistry and biomedicine. The work puts forward a selective, sensitive, and miniaturized analytical method based on molecularly imprinted polymers (MIPs) as adsorbent for miniaturized tip solid‐phase extraction (MTSPE) in the separation of binaphthylamine enantiomer. This method combines the advantages of MIPs (high selectivity), MTSPE (low consumption), and high‐performance liquid chromatography (HPLC, high sensitivity). A simple synthesis methodology of MIP (P2) was conducted through bulk polymerization with (S)‐(−)‐1,1′‐binaphthyl‐2,2′‐diamine (S‐DABN) as template together with methacrylic acid monomer, and ethylene glycol dimethacrylate as cross‐linker in proper porogen, realizing a selective recognition and efficient enrichment for S‐DABN. The method exhibited appreciable linearity (0.06–1.00 mg ml−1), low quantification limit (0.056 mg ml−1), good absolute recoveries (45.70%–69.29%), and high precision (relative standard deviations ≤ 3.54%), along with low consumption (0.50 ml sample solution and 25.0 mg adsorbent). Based on the density functional theory, computational simulation was used to make a preliminary prediction for rational design of MIPs and gave a reasonable elaboration involving the potential mechanism of templates interacting with functional monomers. The adsorption kinetics and thermodynamics were investigated to evaluate the recombination process of substrates. In addition, the selectivity of MIPs for S‐DABN was obtained by MIP‐MTSPE coupled with HPLC, which supports the feasibility of this convenient design process. The proposed method was employed for selective extraction of S‐DABN and exhibited promising potential in the application of chiral analysis. [ABSTRACT FROM AUTHOR]

Heterocyclic aromatic amines (HCAs) are highly carcinogenic and mutagenic chemicals. This study reports on the development of magnetic molecularly imprinted polymers (MMIPs) for the purification and quantification of HCAs. A novel magnetic molecularly imprinted polymer was successfully prepared using a surface molecular imprinting method using functionalized Fe particles as the magnetic cores. 2-Amino-3-methylimidazo[4,5-f]quinoline (IQ) was used as a molecular template; methacrylic acid (MAA), ethylene glycol dimethyl acrylate (EGDMA), 2, 2'-Azobis (2-methyl-propionitrile) were used as the functional monomer, crosslinker, and initiator, respectively. The use of the template/ functional monomer/crosslinking agent at a ratio of 1:4:20 resulted in a product with better adsorption properties (3.24 mg/g). The HCAs were successfully detected and quantified in processed meat samples by MISPE and LC-MS/MS. Under the final optimized detection conditions, the proposed method offered good linearity (R > 0.995) for the five HCAs with an acceptable level of precision, and an LOQ of 0.05 ng/g was successfully achieved. [ABSTRACT FROM AUTHOR]

Sample pretreatment is one of the most crucial and error-prone steps of an analytical procedure; it consents to improve selectivity and sensitivity by sample clean-up and pre-concentration. Nowadays, the arousing interest in greener and sustainable analytical chemistry has increased the development of microextraction techniques as alternative sample preparation procedures. In this review, we aimed to show two different categorizations of the most used micro-solid-phase extraction (μSPE) techniques. In essence, the first one concerns the solid-phase extraction (SPE) sorbent selection and structure: normal-phase, reversed-phase, ion-exchange, mixed-mode, molecular imprinted polymer, and special techniques (e.g., doped cartridges for specific analytes). The second is a grouping of the commercially available μSPE products in categories and sub-categories. We present every device and technology into the classifications paying attention to their historical development and the actual state of the art. So, this study aims to provide the state-of-the-art of μSPE techniques, highlighting their advantages, disadvantages, and possible future developments in sample pretreatment. [ABSTRACT FROM AUTHOR]

[Display omitted] • This paper focuses on a novel analytical method based on packed-nanofibers solid-phase extraction coupled with HPLC-FLD to determine aflatoxins G1, B1, G2, B2 in foods, which contribute vitally to the application of nanoscience and material technology on the agricultural and food chemistry and analytical field. • This study confirmed that the as-synthesized electrospun nanofibers as adsorbent displays preferable potential practical application in the simultaneous pretreatment and analysis of toxins from various samples. • Under optimized conditions, one-step sample pretreatment integrating extraction, purification, enrichment and elution, was realized. The method can simultaneously process 12 samples within 5 min on a semi-automatic array SPE processor. A novel analytical method based on nanofiber-packed solid-phase extraction (PFSPE) combined with HPLC-FLD has been successfully developed and applied to determine aflatoxin B1, B2, G1, G2 in foods. In order to effectively adsorb analytes from complex food matrices, four types of nanofibers based on skeleton of polystyrene–polyvinyl pyrrolidone were prepared by electrospinning and applied as adsorbent to home-made solid-phase extraction device. The effects of type of nanofibers, pH of sample, type and concentration of salt ion, type of activation solvent, type and volume of eluent, amount of nanofibers, and extraction time on the adsorption/desorption were investigated and optimized. Under optimal conditions, the method showed satisfactory linear relationship, with limits of detection (LODs) of 0.07–0.17 ng g−1, intra-day and inter-day RSDs for spiked samples of 1.3–8.0 % and 1.9–5.8 %, and absolute recoveries in the range of 60.1–98.4 %. The results presented the great potential to be utilized to determine AFs in foodstuffs. [ABSTRACT FROM AUTHOR]

• DLP 3D printing – using resin and C18 silica suspension for pharmaceutical analysis. • Study refines printing, material, and extraction parameters for enhanced performance. • Cost-effective, quick and inclusive: cheap 3D-printer with widely available materials. • 3D printing fabricates extraction devices – shaped as needed, with C18 silica particles. • 3D printed devices exhibit precise and accurate analytical performance. In recent years, there has been an increasing worldwide interest in the use of alternative sample preparation methods. Digital light processing (DLP) is a 3D printing technique based on using UV light to form photo-curable resin layer upon layer, which results in a printed shape. This study explores the application of this technique for the development of novel drug extraction devices in analytical chemistry. A composite material consisting of a photocurable resin and C18-modified silica particles was employed as a sorbent device, demonstrating its effectiveness in pharmaceutical analysis. Apart from estimating optimal printing parameters, microscopic examination of the material surface, and sorbent powder to resin ratio, the extraction procedure was also optimised. Optimisation included the type and amount of sample matrix additives, desorption solvent, sorption and desorption times, and proper number of sorbent devices needed in extraction protocol. To demonstrate this method's applicability for sample analysis, the solid-phase extraction followed by gas chromatography coupled with mass spectrometry (SPE-GC–MS) method was validated for its ability to quantify benzodiazepine-type drugs. This evaluation confirmed good linearity in the concentration range of 50–1000 ng/mL, with R2 values being 0.9932 and 0.9952 for medazepam and diazepam, respectively. Validation parameters proved that the presented method is precise (with values ranging in-between 2.98 %-7.40 %), and accurate (88.81 % to 110.80 %). A negative control was also performed to investigate possible sorption properties of the resin itself, proving that the addition of C18-modified silica particles significantly increases the extraction efficiency and repeatability. The cost-effectiveness of this approach makes it particularly advantageous for single-use scenarios, eliminating the need for time-consuming sorbent-cleaning procedures, common in traditional solid-phase extraction techniques. Future optimisation opportunities include refining sorbent size, shape, and geometry to achieve lower limits of quantification. As a result of these findings, 3D-printed extraction devices can serve as a viable alternative to commercially available SPE or solid-phase microextraction (SPME) protocols for studying new sample preparation approaches. [ABSTRACT FROM AUTHOR]

Some metals are needed in the regular functions of living organisms, albeit in very small amounts, so the presence of these metals becomes important (such as copper, zinc, iron, etc.). However, some of them are toxic and these toxic metals are accepted as dangerous trace metals for the environment and food in which people live. These metals (lead, mercury, cadmium, arsenic, zinc, iron, copper, manganese, chromium) can be harmful due to their conversion to toxic components at high concentrations. Therefore, in modern analytical chemistry there is a tendency to develop simple, environmentally safe, sensitive and selective methods for the determination of trace metals. Due to the low concentration of trace metals, a separation and preconcentration technique is often required. One of the most commonly used techniques is the solid phase extraction (SPE) technique. Recent tendency in the field of solid phase extraction is related to synthesis of the new sorbent materials with good performance, such as high resistance to acids and bases, selective for analytes, large surface area and high adsorption capacity. Because of the maximum adsorption capacities of graphene (G) and graphene oxide (GO) are much higher than those of the recently reported sorbents, G and GO nanosheets can be used in classical SPE of both organic compounds and metal species, with successfully. [ABSTRACT FROM AUTHOR]

Abstract Background Solid phase extraction has been an effective tool for the determination of metal ions at trace or sub trace level from environmental aquatic streams. Sensitivity, accuracy, versatility and reusability of adsorbent entitle the solid phase as effective technique for the determination of metal ions. Methods A solid phase extraction procedure has been described for the determination of Cd, Cu, and Pb by High Resolution–Continuum Source Flame Atomic Absorption Spectrometry HR-CS FAAS using a mini-column of Mucor pusillus (Lindt., 1886) immobilized on Amberlite XAD-4. Method has been optimized by changing the pH of analyte solution, solid phase dosage, volume of eluents, flow rate of sample solution and volume of the sample solutions. Results The recoveries of Cd, Cu, and Pb under the optimum conditions were 99±3%, 97±2% and 96±2%, respectively. The resulting preconcentration procedure ensured a 50-fold improvement in the sensitivity of the elements. The detections limits were 62, 74 and 235 ng/mL for Cd, Cu, and Pb before enrichment, respectively. The method was validated by analysis of tomato leaves reference materials (SRM 1573a). Conclusions The proposed enrichment method has been successfully applied for the determination of Cd, Cu, and Pb in tomato leaves and water samples with a relative error ≤8%. This method is simple, sensitive, and accurate especially for water sample, only 200 mg of sorbent are required to capture the analytes. It can be concluded that the use of Mucor pusillus (Lindt., 1886) enhanced the sorption ability of Amberlite XAD-4 resin for the retention of Cd, Cu, and Pb.

In this review, the applications of graphene and its derivatives in the chemical analysis have been described. The properties of graphene materials which are essential for their use in chemical and biochemical analysis are characterized. The materials are used in sensors and biosensors, in electrochemistry, in chromatography and in the sample preparation techniques. Chemical and electrochemical sensors containing graphene materials are useful devices for detecting some chemical and biochemical compounds. Chromatographic columns for HPLC with graphene containing stationary phases may be used for separation of polar and nonpolar components of some specific mixtures. Graphene materials could be successfully employed during sample preparation for analysis with SPE, magnetic SPE, and SPME techniques. The review of the applications of graphene (G) and its derivatives, graphene oxide (GO) and reduced graphene oxide (rGO), in chemical and biochemical analysis is proposed. The electron donor-acceptor and proton donor-acceptor interactions for the graphene based materials – analytes systems and their impact on the analysis results are discussed, particularly: i) in electrochemistry, ii) in chromatography, iii) in modern sample preparation techniques iv) in sensors of different types. The essence of the thermal stability and the nomenclature of the graphene based materials in their different applications in chemical systems of different classes was discussed (and suggested). The benefits of using SPME fibers with immobilized graphene materials have been presented in detail. [ABSTRACT FROM AUTHOR]

Green Analytical Chemistry guidelines mainly encourage the use of direct and portable methodologies to perform analytical determinations in various areas. However, this target is not possible in most cases, and it requires a sample pre-treatment. This additional step increases the number of stages of the method and the analysis cost, but also its environmental impact and risks to the operator. Therefore, the scientific community is currently focused on the development of novel green sample treatment methodologies. Thus, an update of the main novelties found in the literature about the development of green analysis methodologies for sample treatment has been carried out, highlighting those most promising and with high potential to be implemented in the laboratories of the future. Moreover, special attention has been paid to the evaluation of the relevance and potential of AGREEprep, a greenmetric tool specifically dedicated to the estimation of greenness character of sample treatment methodologies. [Display omitted] • Recent developments of green analysis methodologies for sample treatment have been reviewed. • The relevance and potential of AGREEprep greenmetric tool has been evaluated. • Today's Green Analytical Chemistry shows a 0.61 AGREEprep value. • Analytical Chemistry is in very good shape and is growing focused on the development of green extraction methodologies. [ABSTRACT FROM AUTHOR]

Despite the significant advances in analytical instruments, applying a sample preparation step before the final analysis has a great deal of importance. This fact is attributed to the complexity of the sample matrices and the existence of the analytes at trace levels. The recent trends in analytical chemistry are focused on downscaling and development of new sample preparation methods. Micro solid-phase extraction (pipette tip and spin column) and thin film solid-phase microextraction are among the relatively new miniaturized concepts, which have recently achieved much attention thanks to their unique advantages. In this review, these methods and their latest achievements, including possible configurations, different types of exploited commercial and synthesized sorbents, and their potential for automation and routine laboratory tasks are discussed. Finally, the chromatographic applications of these methods are investigated for the analysis of different analytes in various sample matrices. • An update on the state-of-the-art of PT-µSPE, SC-µSPE and TF-SPME were viewed. • Different types of commercial and synthesized sorbents used in these methods were summarized. • Configuration and automation of these methods were discussed. • Chromatographic application of these methods were investigated. [ABSTRACT FROM AUTHOR]

Green analytical chemistry concept, involving the development of analytical methodologies with an environmental concern, encourages the use of direct analysis to avoid any sample treatment that involves energy and reagent consumption and generation of wastes. However, the determination of target analytes at trace concentration levels or in complex matrices frequently requires previous extraction, pre-concentration, or clean-up steps offering thus, additional possibilities for greening classical methods. So, a green evaluation of alternative extraction techniques to currently used ones for the extraction of solid, liquid, and gaseous samples has been carried out in this study. Moreover, the incidence of the continuous increase of laboratory plastic ware consumption, employed for sample treatment, has been highlighted and discussed as a new challenge to enhance the sustainability of analytical methods. • Green extraction placed in the frame of green analytical chemistry. • Miniaturization, automation, energy and consumables saving and on-line waste treatment, as greening strategies. • The problem of single use of plastic consumables enlightened. [ABSTRACT FROM AUTHOR]

Abstract Sample pretreatment is an essential step in analytical chemistry, especially for the analysis of organic pollutants from environmental, biological and food samples. Covalent organic frameworks (COFs) are an emerging group of microporous materials. Recently, COFs have attracted increasing attentions in the field of sample pretreatment due to their advantages such as high surface area, tunable pore size, good chemical selectivity and thermal stability. This review outlined the diverse ways for the facile preparation of COFs, and also summarized the applications of COFs as novel sorbents for the extraction of diverse targeted analytes (such as polycyclic aromatic hydrocarbons, phenols, pyrethroids and pesticides) from complex samples. In addition, the deficiencies and development prospects of COF materials for sample pretreatment in the future were also discussed. This review hopefully can stimulate interdisciplinary research at the intersection of COFs and sample pretreatment. [ABSTRACT FROM AUTHOR]

Abstract: Works of researchers of the Division of Analytical Chemistry of Moscow State University on the use of hypercrosslinked polystyrenes for the preconcentration and separation of organic compounds and ions of elements for the purpose of their subsequent determination are systematized. The works are devoted to the study of the adsorption of compounds of various classes on these materials and a possibility of combining the preconcentration of substances with modern methods of chemical analysis for the determination of amines, phenols, methylxanthines, sulfonamides, tetracyclines, and other compounds and ions of elements (gold, platinum, and rare-earth elements). The issues of using hypercrosslinked polystyrenes as stationary phases in chromatography and the creation of magnetic adsorbents based on them are also discussed. [ABSTRACT FROM AUTHOR]

[Display omitted] • The review summarizes the most important roles of DESs in solid-phase (micro)extraction techniques. • The use of DESs as modifiers of sorbents, parts of sorbents, and directly as sorbents is discussed. • The use of DESs as eluting solvents and as dispersing agents is described. • The use of DESs in hyphenated extraction techniques is presented. One of the key challenges of modern analytical chemistry is the monitoring of trace amounts of contaminants using sensitive and selective instrumental techniques. Due to the variety and complexity of some samples, it is often necessary to properly prepare a sample and to perform a preconcentration of trace amounts of analytes. In line with the principles of Green Analytical Chemistry (GAC), it is important for an analytical procedure to reduce labor and time consumption and to decrease the use of volatile and hazardous solvents. Therefore, solvent-free extraction techniques, such as SPE, µSPE, SPME and their various modifications, which are mainly aimed at increasing their "greenness", have been very popular for many years. Deep eutectic solvents fit perfectly into GAC principles, which is why they have been used as extractants in liquid-phase microextraction techniques for a long time. This review is a follow-up to our recently published article on the use of deep eutectic solvents (DESs) in liquid-phase microextraction techniques and summarizes the most important applications of DES in solid-phase (micro)extraction techniques. [ABSTRACT FROM AUTHOR]

Dissolved organic matter (DOM) is ubiquitous in natural waters and plays a central role in the biogeochemistry in riverine, estuarine and marine environments. This study quantifies and characterizes solid-phase extractable DOM and trace element complexation at different salinities in the Weser and Elbe River, northern Germany, and the North Sea. Dissolved organic carbon (DOC), total dissolved nitrogen (TDN), Co and Cu concentrations were analyzed in original water samples. Solid-phase extracted (SPE) water samples were analyzed for DOC (DOCSPE), dissolved organic nitrogen (DONSPE), sulfur (DOSSPE) and trace metal (51V, 52Cr, 59Co, 60Ni, 63Cu, 75As) concentrations. Additionally, different pre-treatment conditions (acidification vs. non-acidification prior to SPE) were tested. In agreement with previous studies, acidification led to generally higher recoveries for DOM and trace metals. Overall, higher DOM and trace metal concentrations and subsequently higher complexation of trace metals with carbon and sulfur-containing organic complexes were found in riverine compared to marine samples. With increasing salinity, the concentrations of DOM decreased due to estuarine mixing. However, the slightly lower relative decrease of both, DOCSPE and DONSPE (~77%) compared to DOSSPE (~86%) suggests slightly faster removal processes for DOSSPE. A similar distribution of trace metal and carbon and sulfur containing DOM concentrations with salinity indicates complexation of trace metals with organic ligands. This is further supported by an increase in Co and Cu concentration after oxidation of organic complexes by UV treatment. Additionally, the complexation of metals with organic ligands (analyzed by comparing metal/DOCSPE and metal/DOSSPE ratios) decreased in the order Cu > As > Ni > Cr > Co and thus followed the Irving-Williams order. Differences in riverine and marine trace metal containing DOMSPE are summarized by their average molar ratios of (C107N4P0.013S1)1000V0.05Cr0.33Co0.19Ni0.39Cu3.41As0.47 in the riverine endmember and (C163N7P0.055S1)1000V0.05Cr0.47Co0.16Ni0.07Cu4.05As0.58 in the marine endmember. [ABSTRACT FROM AUTHOR]

Kava is regaining its popularity with detailed characterizations warranted. We developed an ultraperformance liquid chromatography high-resolution tandem mass spectrometry (UPLC-MS/MS) method for major kavalactones (kavain, dihydrokavain, methysticin, dihydromethysticin and desmethoxyyangonin) with excellent selectivity and specificity. The method has been validated for different matrices following the Food and Drug Administration guidance of analytical procedures and methods validation. The scope of this method has been demonstrated by quantifying these kavalactones in two kava products, characterizing their tissue distribution and pharmacokinetics in mice, and detecting their presence in human urines and plasmas upon kava intake. As expected, the abundances of these kavalactones differed significantly in kava products. All of them exhibited a large volume of distribution with extensive tissue affinity and adequate mean residence time (MRT) in mice. This method also successfully quantified these kavalactones in human body fluids upon kava consumption at the recommended human dose. This UPLC-MS/MS method therefore can be used to characterize kava products and its pharmacokinetics in animals and in humans. [ABSTRACT FROM AUTHOR]

In the present work, a novel infrared-assisted extraction coupled to headspace solid-phase microextraction (IRAE-HS-SPME) followed by gas chromatography-mass spectrometry (GC-MS) was developed for rapid determination of the volatile components in green tea. The extraction parameters such as fiber type, sample amount, infrared power, extraction time, and infrared lamp distance were optimized by orthogonal experimental design. Under optimum conditions, a total of 82 volatile compounds in 21 green tea samples from different geographical origins were identified. Compared with classical water-bath heating, the proposed technique has remarkable advantages of considerably reducing the analytical time and high efficiency. In addition, an effective classification of green teas based on their volatile profiles was achieved by partial least square-discriminant analysis (PLS-DA) and hierarchical clustering analysis (HCA). Furthermore, the application of a dual criterion based on the variable importance in the projection (VIP) values of the PLS-DA models and on the category from one-way univariate analysis (ANOVA) allowed the identification of 12 potential volatile markers, which were considered to make the most important contribution to the discrimination of the samples. The results suggest that IRAE-HS-SPME/GC-MS technique combined with multivariate analysis offers a valuable tool to assess geographical traceability of different tea varieties. [ABSTRACT FROM AUTHOR]

LNA-i-miR-221, a 13-mer oligonucleotide, is a new miR-221 inhibitor that could be used as a novel drug for multiple myeloma. Herein, an ion-pair reversed phase liquid chromatography–tandem mass spectrometry (LC–MS/MS) method has been developed and validated for the quantification of LNA-i-miR-221 in rat plasma. Plasma samples were prepared with an initial phenol/chloroform/isoamyl alcohol liquid–liquid extraction followed by a solid phase extraction. Chromatographic separation was performed with a gradient system on a HALO C18 column using hexafluoro-2-propanol/triethylamine buffer and methanol as mobile phase at a flow rate of 0.4 mL/min. Under these conditions LNA-i-miR-221 and the analogue internal standard are co-eluted at 1.2 min. The detection was carried out in multiple reaction monitoring (MRM) mode using a negative electrospray ionization (ESI) interface. The assay showed a good linearity within the calibration range 10–10000 ng/mL. The precision, accuracy, and recovery values were found to be <15% (<20% at LLOQ), 100 ± 15%, and 97.6–103.7%, respectively. This method was successfully applied to measure the concentrations of LNA-i-miR-221 in plasma samples following the intravenous administration during a 4-week toxicity study in rats. [ABSTRACT FROM AUTHOR]

Ambient mass spectrometry provides great convenience for fast screening, and has showed promising potential in analytical chemistry. However, its relatively low sensitivity seriously restricts its practical utility in trace compound analysis. In this review, we summarize the sampling and analyte enrichment strategies coupled with nine modes of representative ambient mass spectrometry (desorption electrospray ionization, paper vhspray ionization, wooden-tip spray ionization, probe electrospray ionization, coated blade spray ionization, direct analysis in real time, desorption corona beam ionization, dielectric barrier discharge ionization, and atmospheric-pressure solids analysis probe) that have dramatically increased the detection sensitivity. We believe that these advances will promote routine use of ambient mass spectrometry. [ABSTRACT FROM AUTHOR]