Microextraction Procedure Research Articles

Optimization of a solidified floating organic drop microextraction procedure through an experimental design for the simultaneous determination of four non‐steroidal anti‐inflammatory drugs in river water

AbstractTo simultaneously determine the non‐steroidal anti‐inflammatory drugs ketoprofen, nimesulide, diclofenac and ibuprofen in river water, a simple and cost‐effective solidified floating organic drop microextraction method coupled with high‐performance liquid chromatography was developed. Through multivariate optimization, the variables extracting volume, dispersive volume, sample pH and ionic strength were optimized by a full factorial design 24 and Doehlert matrix. The optimized experimental conditions were 30 μL of extracting solvent (1‐dodecanol), 300 μL of dispersive solvent (acetonitrile) and sample pH of 2. The optimized method showed low limits of detection (0.05 to 0.09 μg L−1), satisfactory recoveries (up to 118%) and enrichment factors ranging from 67 to 197. The optimized method applied in river water samples showed low matrix effects, making it possible to apply this method successfully for the quantification of four NSAIDs in river water samples.

Development, optimization and comparison of solid-liquid and liquid-liquid microextraction for the determination of four flavonols in Schinus molle L. using high-performance liquid chromatography coupled with second-order data modeling.

Flavonoids are particularly interesting because they have a broad spectrum of biological effects, including antioxidant and free radical scavenging activities. In this work, solid-liquid microextraction and dispersive liquid-liquid microextraction enhanced by ultrasound were developed and compared with the conventional method (Soxhlet extraction) to optimize the extraction of four flavonoids: rutin, quercitrin, quercetin, and myricetin in samples of Schinus molle (Aguaribay). During the development of the analytical method, different chemometric tools were used to optimize the microextraction procedure. In addition, an analytical method based on high-performance liquid chromatography with diode array detector (HPLC-DAD) and secondorder calibration using multivariate curve resolution-alternating least square (MCR-ALS) is presented to quantify the flavonoids with limits of quantification between 0.011 and 0.082µgmL-1. Finally, solid-liquid microextraction using 4.00mL water/ethanol (54.3:45.7%), 14s vortex, and 45min was selected as the most suitable method due to its high recovery rate and environmental friendliness (with a greenness score of 0.78). After the optimization step, the concentrations found in the plant samples were 1825.3, 632.6, 110.2, and 18.9µgg-1 for rutin, quercitrin, quercetin, and myricetin, respectively. The present work is the first achievement of simultaneously determining these four analytes with exceptional sensitivity, demonstrating lower LOQs compared to previous reports.

Chromatographic determination of oxytetracycline in milk product samples using liquid-liquid microextraction procedure

Miniaturized procedures for chemical analysis give the possibility of a significant reduction in quantities of organic solvents used during isolation and determination processes. Liquid-liquid microextraction (LLME) using butanol as an extractant was investigated to selectively isolate oxytetracycline (OTC) antibiotic residues from dairy products. The optimal conditions of LLME were established after deproteinization of the samples. The isolation procedure for OTC was performed using 700 µL of butanol. The extracts were analysed by HPLC-UV and LC-MS/MS. A satisfactory analyte recovery was achieved in the range 97.6%–98.9%. The concentration of the linearity range of the studied antibiotic should allow its determination at the level of MRL values. The limit of detection during HPLC-UV and LC-MS/MS determination of OTC in milk samples was 9.9·10−8 mol L−1 (47.85 µg kg−1) and 5.7·10−9 mol L−1 (2.75 µg kg−1), respectively. The precision (1.7%–8.6%) of the methods using LLME isolation of OTC varied depending on the kind of sample and the chromatographic technique used. The developed methods were applied to the analysis of milk and cottage cheese to estimate the presence and detection of OTC content.

Application of 1-octanol in the extraction and GC-FID analysis of volatile organic compounds produced in biogas and biohydrogen processes

Information about the volatile organic compounds generated in biogas and hydrogen production bioreactors is essential to elucidate the metabolic routes and varying yields of CH4 and H2 processes. In this work, the determination of 12 compounds (acetone, methanol, ethanol, 1-propanol, 1-butanol, and acetic, propanoic, butyric, isovaleric, valeric, caproic, and lactic acids) was performed by gas chromatography, after a vortex-assisted liquid–liquid microextraction (VALLME) procedure using 1.2 mL of crude sample and 400 µL of 1-octanol. Optimization of the separation process was performed, considering the solvent viscosity. The analytical curves were validated using ANOVA, demonstrating satisfactory precision and accuracy. Selectivity was confirmed by GC–MS analysis, which allowed the detection of glycerol, 1,3-propanediol, and 1,3-butanediol in some samples. Methanol levels exceeded the upper limit of quantification, with acetic acid and ethanol being the predominant compounds in the analyzed reactors. An additional investigation was conducted to assess potential interferences for lactic acid. The developed method employs a biodegradable extraction solvent, without any need for a dispersing solvent, and involves a single chromatographic run, without any derivatization steps.

Boosting miniaturization in clinical analysis: determination of bisphenols in human serum and urine by miniaturized stir bar sorptive dispersive microextraction.

In this work, a miniaturized and sustainable method for the determination of endocrine-disrupting bisphenols in human serum and urine employing the miniaturized stir bar sorptive dispersive microextraction (mSBSDME) approach has been developed. As bisphenols are conjugated in the human body to their glucorinated and sulfated forms, an enzymolysis employing a commercial mixture of β-glucuronidase and arylsulfatase was carried out prior to the microextraction procedure to determine their total content. A magnetic covalent organic framework (COF) was employed as thesorbent to carry out the extraction of the analytes from the biological matrixes, showing good extraction performance dueto its hydrophobic, π-π, and dipole-dipole interactions with the analytes. As instrumental detection, liquid chromatography-tandem mass spectrometry (LC-MS/MS) was employed to achieve good sensitivity and selectivity. The method was validated for both matrixes, showing good linearity at least up to 100 ng mL-1, limits of detection in the low ng mL-1 range, good precision values (relative standard deviations below 15%), and good accuracy (relative recoveries between 80 and 127%). In order to show the applicability of the developed method, five samples from female volunteers were analyzed with the final aim of offering a practical tool for monitoring the female population's exposure to these highly endocrine-disrupting compounds. This new procedure enhances the implementation of miniaturized sample preparation approaches in biological samples for clinical analysis, giving special relevance to the sustainability of the method.

Green liquid supra molecular solvent (SUPRA) phase for fast and selective liquid-liquid micro-extraction of Co2+ ions from aqueous samples

The limitation of Liquid-liquid micro-extraction (LLME) procedures can be the need for the use of a dispersive solvent which should be soluble in both of aqueous and organic phases. In this research, a new method named SUPRA-based LLME, is introduced which uses supra molecular solvent (SUPRA), as an environmentally friendly solvent, for quantitative and selective extraction of Co2+ ions from its aqueous solution via liquid-liquid micro-extraction process. The aqueous immiscible SUPRA phase, composed of vesicles of decanoic acid was synthesized via ex-situ procedure and used as a single liquid phase. In order to make the SUPRA phase selective, N, Nʹ-disalicylidene-3, 4-diaminotoluene (H2dst) was synthesized and completely dissolved in the SUPRA phase. Then the lipophilic and selective prepared liquid sorbent, as liquid SUPRA phase, was used for the facile and selective LLME of Cobalt (II) ions from aqueous samples. Experimental studies showed that there was not any need of dispersing solvent and so liquid SUPRA phase could easily dispersed in the aqueous phase and then separated by centrifugation as the supernatant phase. Then the effects of some important variables on the extraction efficiency were also investigated and optimized. The results showed that under optimal conditions, efficient extraction of Cobalt (II) ions was achieved, about 99 % ± 2.7 (n = 10), in a short time of extraction (10 min), and the linear range of calibration curve was from 500 to 2500 μg L−1 of Cobalt(II) with correlation coefficient of 0.999. Also detection limit and pre-concentration factor were 150 μg L−1 and 35.2, respectively. Although the experimental conditions were optimized for extraction of only Co2+ ions, the selectivity study showed a high tendency of selective liquid SUPRA phase toward extraction of both of Co2+ and Ni2+ ions. The matrix effects on the SUPRA-based LLME of Co2+ ions from matrix samples, factory wastewater and sea-water, were studied and least matrix effects were observed.

Development of “water-lean” solvent-based air-assisted liquid–liquid microextraction; application in the extraction of some phenolic compounds from water and wastewater samples prior to GC-FID analysis

In the present study, an efficient, robust, and reliable air–assisted liquid–liquid microextraction procedure was introduced based on a “water-lean” solvents for the extraction and preconcentration of phenolic compounds from spring water and petrochemical, Songun mine, and municipal wastewater samples. For this purpose, various hydrophobic water-lean solvents composed of organic solvents consisting of carbon tetrachloride, dichloromethane, 1,1,2-trichloro-1,2,2-trifluoroethane, and chloroform with amines including n-butylamine, di-n-butylamine, iso-propylamine, n-hexylamine, diethylamine, pyridine, aniline, toluidine, and benzylamine) were prepared and they were used as the new extraction media. The selected compounds (phenol, 1-naphthol, 2-naphthol, 4- chlorophenol, o-cresol, 2-nitrophenol, and 2-nitroso-1-naphthol) were extracted from sample solution containing sodium chloride (5 %, w/v) using 200 µL of a water-lean solvent composed of dichloromethane: butylamine (1:1) by performing the sucking/injection cycles for four times. The effect of several parameters on the extraction efficiency of the method, consisting of type and volume of water-lean solvent, extraction numbers, pH, and ionic strength, were examined and optimized by “one-variable-at-one-time” strategy. High enrichment factors (315–420), respectable extraction recoveries (63–84 %), low limits of detection (0.23–0.56 ng mL−1) and quantification (0.77–1.86 ng mL−1), and broad linearity of the calibration curve (1.86–500 ng mL−1) demonstrated satisfactory performance of the present approach. The relative standard deviation for the extraction of 50 and 100 ng mL−1 of each phenol (n = 6) were ≤ 6.3 % for intra- and inter-day precisions. Eventually, the proposed method was efficaciously performed for extraction and determination of the selected analytes in various water and wastewater samples and phenol and 4-chlorophenol were found in the samples at ng mL−1 level.

Design of a novel deep eutectic solvent for microextraction of Lissamine green B from food Samples: A green approach

The extraction of Lissamine Green B (LGB) from food matrices poses a challenge due to its low concentration and interference from other matrix compounds. In this study, a novel green approach utilizing a deep eutectic solvent (DES) for dispersive liquid microextraction (GDES- DLLME) of LGB is presented. The DES, formulated from eco-friendly components and synthesized through mechanochemical methods for the first time, presents a sustainable alternative to traditional solvents. The DES characterization was implemented via 1H and 13C Nuclear Magnetic Resonance spectroscopy (NMR) analysis. The microextraction procedure was optimized for maximum efficiency, considering factors such as extraction time, DES composition, and sample pH, THF volume, NaCl amount, sample volume etc. The developed method was then applied to various food samples using spectrophotometric detection for the quantitative analysis of LGB, including water samples, beverages and foods. Furthermore, analytical performance values such as limit of detection (LOD), limit of quantification (LOQ), relative standard deviation (RSD), and preconcentration factor (PF) were calculated as 0.76 ng/mL, 2.56 ng/mL, % 4.6, and 22.5 respectively. The results demonstrated the effectiveness of simply generated DES as an extraction solvent and enabled sensitive and selective determination of LGB in complex food matrices. This eco-friendly method is promising for food safety and quality control applications, providing a sustainable solution for the analysis of LGBs in food.

Rapid and eco-friendly microextraction procedure based on green hydrophobic deep eutectic solvent for simultaneous determination of five sex hormones from cosmetic samples

Hormones, which are among the endocrine disruptors, are used in many fields and their use in cosmetic products has recently attracted considerable attention. Despite the negative health consequences, there is no detailed guidance that limits the use of these endocrine disruptors. This study aimed to develop a green hydrophobic deep eutectic solvent (HDES)-based microextraction method for the detection and quantification of sex hormones (progesterone, β-estradiol, estrone, ethinylestradiol, and testosterone) in different cosmetic products. The best value for extraction recovery was obtained by using DL-menthol and dodecanoic acid as green HDES in a 4:1 mole ratio. Optimization parameters such as HDES volume, pH, sample volume, centrifugation time, mixing type, and mixing time were investigated for cosmetic samples to be used as real samples. Furthermore, the extraction recovery values ranged from 85.7 % to 101.3 % and the detection limit was between 2.33–3.30 ng mL−1. Additionally, three different greenness methods, namely ComplexGAPI, AGREEprep, and BAGI, were used to evaluate how green the proposed method is in this study. The microextraction procedure developed in this study was successfully applied to five different cosmetic samples that will be used as real samples to detect and determine sex hormones.

Development of an ionic liquid-based microextraction system (ILBME) for sensitive spectrophotometric analysis of neodymium(III) ions in environmental samples

ABSTRACT Introducing a precise, sensitive and simple system for determining neodymium(III) ions in aquatic samples could enhance the capabilities of routine instruments, particularly in terms of detection limits. Coupling a powerful preconcentration system, such as ionic liquid-based microextraction (ILBME), with a spectrophotometer can successfully achieve this goal. A sensitive and simple microextraction method based on a task-specific ionic liquid, designated [PDmim][Cl2], is described, in which the imidazolium-based ionic liquid served dual roles as both the chelating agent and the extraction phase. The ionic liquid was synthesized and characterized before being applied in microextraction procedure. The optimized microextraction results indicate that neodymium concentrations up to 5.10 µg L−1 can be successfully determined. The method characteristics, including the limit of detection (LOD), limit of quantification (LOQ), intra-day and inter-day relative standard deviations (RSDs), preconcentration factor (PF), enrichment factor (EF) and linear dynamic range (LDR), were found to be 1.53 µg L−1, 5.10 µg L−1, 3.83%, 4.44%, 123, 111.1 and 5.0–125.0 µg L−1, respectively. For method validation, the standard addition method using standard reference material (SRM) was employed, and the recovery range from real samples analyses was between 99.3% and 101.0%.

Development of a green microextraction procedure for determining polyaromatic hydrocarbons in electronic equipment plastics

The global proliferation of electronic devices, driven by technological advancements, has led to the release of organic pollutants from the plastic components of these devices, particularly in indoor environments. Among these pollutants, polycyclic aromatic hydrocarbons (PAHs), which are emitted into the air from plastic components, play a critical role in the field of indoor environment pollution. Consequently, effectively monitoring the PAH content in plastics used in electronic equipment is crucial for preventing indoor contamination.In this study we aimed to develop a fast, inexpensive, easy, and environmentally friendly analysis method for determining PAH content in plastic equipment. A dispersive liquid liquid microextraction (DLLME) combined with solidified organic drop (SFO) microextraction technique was developed.Considering the eleven number of parameters that can affect the signal in the DLLME-SFO method, Plackett Burmann's design was applied to select the most three impactful parameters for 18 PAH species. A Box-Behnken experimental design was also applied to optimize the identified parameters. The optimal conditions for the most influential parameters such as solvent type, pH, and the sample weight were identified as 1-dodecanol, 12 and 0.24 g, respectively.The proposed method was validated under these optimized conditions, yielding low detection limits ranging from 0.004 to 0.11 ng mL−1. The calibration curves were linear with correlation coefficients above 0.98 and relative standard deviation (RSD) values ranging from 2.4% to 20%. This method was successfully applied to analyze PAH content in the plastic components of electronic devices. The extraction technique developed in this study is a newly developed technique and has not been previously used to analyze organic pollutants that may be present in electronic equipment plastic.

Handshake of deep eutectic solvent and ionic liquid: Two liquid-liquid microextraction procedures for plant analysis

Plants are subjects of interest due to the secondary metabolites in their extracts which are promising as new pharmaceuticals. Phytochemistry do not have united system of sample preparation or analysis still due to different structure of plant cells, wide broad range of chemical properties and concentrations of bioactive compounds. Such challenges can be addressed in a green chemistry manner using new approaches through smart materials in routine monitoring and researches. Liquid smart materials, such as ionic liquids (ILs) and deep eutectic solvents (DESs) are attractive due to flexible properties, lots of extraction approaches, recycle potential, and direct compatibility with powerful analytical methods.In this study DES-based microextraction procedure with pH-switching was developed. Four choline chloride DESs were suggested as selective extraction phases for polar compounds from acetonitrile extracts. Method was successfully tested on four plants (Iris sibirica L., Hypericum perforatum L., Scutellaria baicalensis G, Citrus reticulata B.). Developed procedure was optimized and validated for the choline chloride – urea (1:2 mol/mol) DES that demonstrated better results in extraction. LOD for rutin was found as 0.05 mg ml−1. For low-polar compound, imidazolium ionic liquid-based dispersive liquid-liquid microextraction procedure was developed. 1-hexyl-3-methylimidazolium salts have demonstrated desired selectivity. The main factors influencing the extraction efficiency have been identified and optimized by design of experiment on two model plants (Iris sibirica L. and Scutellaria baicalensis G.). Validation procedures were done for thymol. LOD for thymol was found as 0.021 mg ml−1.The methods were compared with each other and traditional methanol extraction. The selectivity of the smart materials supports each other, usage of such extraction phases provides same or better results as obtained with methanol.

A capsule phase microextraction protocol combined with GC–MS/MS for the determination of polychlorinated biphenyls in water samples

Due to the adverse effects of polychlorinated biphenyls (PCBs) on human health and ecosystems, their careful monitoring is necessary. In this work, capsule phase microextraction (CPME) combined with gas chromatography-tandem mass spectrometry (GC–MS/MS) was used to extract and determine eight PCBs in water samples. As an extraction device for the CPME procedure, two permeable microporous polypropylene tubes were employed. They contained sol–gel carbowax 20 M (sol–gel CW 20 M) sorbent and a cylindrical magnet. The adsorption and desorption conditions (i.e., type of capsule, sample volume, extraction time, stirring rate, ionic strength, type and volume of eluent, and desorption time) of the microextraction procedure were studied. Under optimum conditions, the extraction was achieved within 20 min using 20 mL of sample at a stirring rate of 1000 rpm, while the elution was performed by immersing the CPME device in 500 μL of acetone for 5 min. Accordingly, the analytical method was validated in terms of linearity, sensitivity, selectivity, enhancement factor, accuracy, and precision, and its greenness and applicability were evaluated. The obtained limits of quantification were equal to 0.010–0.050 μg L−1. The relative recoveries were equal to 91.4 and 110.6 % for intra-day and 88.0–111.2 % for inter-day study, while the relative standard deviation values were better than 10.9 %. Finally, the developed method was used for the analysis of real water samples, proving good fitness-for-purpose.

Application of zwitterionic ionic liquid-based capsule phase microextraction for the HPLC-UV determination of doxycycline in human urine samples

Herein, we describe the utilization of an ionic liquid (IL)/Carbowax 20 M−functionalized sol–gel sorbent for the capsule phase microextraction of doxycycline in authentic human urine samples. This green sample preparation method combines stirring and filtration in a single, standalone sample preparation device, streamlining the sample preparation process. Additionally, it provides rapid extraction kinetics and high extraction efficiency. The experimental conditions (i.e. sorbent type, sample pH and volume, extraction time, ionic strength, elution solvent, and volume) affecting the extraction efficiency of the analyte were studied and optimized. The method was linear in the range of 0.1 – 5.0 μg/mL with a coefficient of determination higher than 0.995. The achieved LOD was found to be 0.02 μg/mL while the lower limit of quantitation (LLOQ) was 0.1 μg/mL. The IL/Carbowax 20 M−functionalized microextraction capsules were reusable at least 30 times for urine samples. The relative recoveries (% RR) ranged between 93.4 – 115.9 % while the precision (expressed as % RSD) was better than 8.1 % in all cases. The robustness of the microextraction procedure and the instrumental HPLC method were separately investigated using Plackett-Burman experimental designs. The analytical protocol demonstrated cost-effectiveness, ease of handling, and speed, leading to increased sample throughput. The green character of the developed method was evaluated using the Green Analytical Procedure Index (GAPI) and Blue Applicability Grade Index (BAGI). Finally, the method’s applicability was demonstrated by analyzing authentic human urine samples after oral administration of a doxycycline-containing pharmaceutical formulation.

Development of Analytical Strategy for the Determination of Cadmium by Flame Atomic Absorption Spectrometry After Dithizone/Deep Eutectic Solvent Probe Based Liquid Phase Microextraction

Liquid phase microextraction (LPME) with a dithizone/deep eutectic solvent (DTZ-DES)-based probe was employed for the determination of trace cadmium by flame atomic absorption spectrometry (FAAS). All extraction parameters were univariately optimized to achieve the highest efficiency and the limits of detection and quantification were 3.5 and 11.8 ng mL−1. Good linearity was obtained from 10 to 200 ng mL−1 with a regression coefficient (R2) of 0.9979. The sensitivity of FAAS system was improved 26.9-fold by the microextraction procedure. The accuracy and applicability of the method were investigated with recovery experiments carried out using corn silk tea extracts. The recovery values with matrix matching calibration were from 81.3 to 114.3%, demonstrating that this environmentally friendly method is applicable for determination of cadmium in tea samples with good accuracy.

Primary alcohol-induced coacervation in alkyl polyglucoside micellar solution for supramolecular solvent-based microextraction and chromatographic determination of phthalates in baby food

This study reports for the first time the phenomenon of supramolecular solvent formation based on alkyl polyglucoside as an amphiphile and primary alcohol as a coacervation agent. The physical properties (density, kinematic viscosity, phase diagram for ternary system) of the supramolecular solvent were investigated, and a mechanism for its formation was proposed. A green and simple microextraction procedure for preconcentration and determination of phthalates in baby foods packaged in plastic packaging was developed as proof-of-concept example. The microextraction procedure assumed separation of analytes from solid phase sample in micellar solution of decyl glucoside and in situ formation of supramolecular solvent for analytes preconcentration after addition of n-heptanol. The determination of phthalates in obtained extracts was implemented by high-performance liquid chromatography with UV–Vis detection. The limits of detection, calculated from a blank test based on 3σ, were determined to be 10 μg kg−1 for dimethyl phthalate, diethyl phthalate, di-n-butyl phthalate, and di-n-octyl phthalate. The developed procedure did not require filtration of sample suspension, and assumed the use of green and biodegradable substances for the supramolecular solvent formation across a wide pH range.

Dispersive solid phase extraction of some sulfonamide antibiotics from milk combined with dispersive liquid-liquid microextraction

A covalent organic framework based dispersive solid phase extraction was developed for extraction of several antibiotics from raw cow's milk samples. For this purpose, first, the milk proteins were precipitated by zinc sulfate and after centrifugation, the analytes were extracted by the sorbent. Then, the analytes were desorbed by a proper eluent and were more concentrated by a microextraction procedure. The extractant was used for the analysis of the analytes by high-performance liquid chromatography-diode array detector. Based on the results, acceptable extraction recoveries (62–71 %) and sensitive limits of detection and quantification in the ranges of 0.11–0.19 and 0.37–0.63 ng mL−1, respectively, were obtained. The method can analyze the analytes in broad concentration range. The introduced approach was used in the analysis of fifteen raw cow's milk samples. The obtained data showed that all samples were free of the analytes. According to these results, the method can be considered an efficient procedure for extracting the analytes from raw milk samples.

Determination of metformin from micro-liter plasma and blood glucose test strip using eco-friendly micro-extraction procedures for point-of-care diagnostics

Metformin is commonly used in the treatment of type 2 diabetes and polycystic ovary syndrome. Beyond these common applications, it also holds promise in treating chronic pain, and as an antiaging and anticancer agent. In addition, it has cardiovascular protective and neuroprotective effects. However, elevated concentrations of metformin in the plasma, such as in patients with renal impairment or with conditions that can disrupt lactate clearance, could cause metformin-associated lactic acidosis. Moreover, metformin can cause a deficiency of vitamin-B12 and folic acid and impact one-carbon metabolism negatively. This study employs micro-extraction procedures to extract metformin from the human plasma and blood glucose test strips followed by detection using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). Under the optimized micro-extraction procedures and by using an eco-friendly base and solvent, the proposed method required only 10 µL of the human plasma and a small piece of the blood glucose test strip for metformin analysis. The method exhibits a linear range of 0.05–5 μg mL−1 with a coefficient of determination (r2) of 0.999 and a limit of detection of 0.01 μg mL−1. The relative standard deviation (RSD) and relative error (RE) were both below 6.7 %. The test strip is a disposable product; its reuse before disposal could increase its additional applicability. Furthermore, major blood proteins and their modifications could be identified using this tiny volume of blood by mass spectrometry after protein digestion. The proposed technique could be invaluable in point-of-care diagnostics, enabling rapid monitoring of metformin plasma concentration and major plasma proteins to help patients mitigate the risk of metformin-associated lactic acidosis. To reduce organic waste in clinical applications, micro-extraction is a simple and efficient protocol for sample preparation using minute volumes of blood samples.

Natural deep eutectic solvent for the simultaneous derivatization and microextraction of isoniazid from human plasma

BackgroundPersonalized medicine is a rapidly revolving field that offers new opportunities for tailoring disease treatment to individual patients. The main idea behind this approach is to carefully select safe and effective medications and treatment plant based on each patient's unique pharmacokinetic profile. Isoniazid is a first-line anti-tuberculosis drug that has interindividual variability in its metabolic processing, leading to significant differences in plasma concentrations among patients receiving equivalent doses. This variability necessitates the creation of individualized treatment regimens as part of personalized medicine to achieve more effective therapy. ResultsIn this work, a deep eutectic solvent-based liquid-liquid microextraction approach for the separation and determination of isoniazid in human plasma by high-performance liquid chromatography with UV–Vis detection was developed for the first time. A new natural deep eutectic solvent based on thymol as a hydrogen bond donor and 4-methoxybenzaldehyde as a hydrogen bond acceptor was proposed as the extraction solvent. The developed microextraction procedure assumed two simultaneous processes during the mixing of the sample and extraction solvent: the derivatization of the polar analyte in the presence of 4-methoxybenzaldehyde (component of the natural deep eutectic solvent) with the formation of a hydrophobic Schiff base (1); mass transfer of the Schiff base from the sample phase to the extraction solvent phase (2). Under optimal conditions, the limits of detection and quantification were 20 and 60 μg L−1, respectively. The RSD value was <10 %, the extraction recovery was 95 %. SignificanceIn this work, the possibility of isoniazid derivatization in the natural deep eutectic solvent phase with the formation of the Schiff base was presented for the first time. The approach provided the separation and preconcentration of polar isoniazid without the use of expensive derivatization agents and solid-phase extraction cartridges. The formation of the Schiff base was confirmed by mass spectrometry.

Sexual hormones monitoring in surface waters and wastewaters from Northern Italy by thin film microextraction coupled with HPLC-MS/MS.

The occurrence of sex steroid hormones, viz. oestrogens and progestins, in aquatic ecosystems is of global concern due to their role as endocrine disrupting chemicals, even at low concentration (μg L-1 or less). Thus, it is essential to monitor these organic pollutants to get a realistic picture of their presence and to control their contamination levels in environmental water bodies. In this respect, we have explored the use of self-prepared polymeric films as novel sorptive phase for the microextraction of 17β-estradiol, 17α-ethinylestradiol, estrone, progesterone, medroxyprogesterone acetate and hydroxyprogesterone. The thin film microextraction procedure has been developed, evaluating different film compositions, sample volumes and elution conditions to recover the sorbed analytes. The overall method provides good reproducibility (RSD < 12%) and recoveries higher than 60%. The final method has been applied to environmental monitoring in surface waters (river and lake samples) and urban wastewater treatment plant effluents and influents from Northern Italy, to get a contamination snapshot of this highly urbanized area.