Thin Film Solid Phase Microextraction Research Articles

Exploring advanced strategies in SPME-HPLC-DAD: Enhancing analytical precision and diverse applications in modern era

In analytical chemistry, the synergy between innovative sample preparation techniques and advanced chromatographic methods has paved the way for unprecedented advancements in the analysis of complex samples. Solid Phase Microextraction (SPME) stands out as a powerful tool for extraction, and preconcentration. When coupled with High-Performance Liquid Chromatography (HPLC) equipped with a Diode Array Detector (DAD), the integrated SPME-HPLC-DAD system emerges as a sophisticated analytical platform, offering enhanced sensitivity, selectivity, and versatility for various applications. Desorption is accomplished by either depositing organic solvent in the desorption chamber or else by flowing the mobile phase through the desorption chamber specificity. An ordinary description, along with a visual illustration, has been thoroughly provided for concepts of developed well-known enhanced thin film SPME cartridges (Figure 2). The tabular representation is also available with proper description like technique name, targeted analyte, column used, mobile phase used, %RSD, extraction recovery, LOD, and data acquired R2 also considered Based on the information available in the present study. Discussed SPME with HPLC-DAD brings a great turning point by successfully utilization in biomedical sciences, environmental monitors, food safety, and clinical analysis This cost-effective, readily available technique is both environmentally friendly and stable, allowing for rapid, reliable, and accurate measurements across a wide range of analyte concentrations, thanks to the utilization of hyphenated techniques. The different strategies of SPME with HPLC -DAD and possible future apllications have been incorporated in the review. The understanding of these techniques is still limited and challenging.

Easy and fast synthesis of MnCo-LDH yolk-shell spheres porous composites applied electrospinning nanofibers highly effective for extracting triazole fungicides

Today, the wide utilization of triazole fungicides due to environmental damage and its side effects has raised global concern. Thus, in this investigation, polyacrylonitrile/MnCo-layered double hydroxides nanofiber was synthesized and applied as an effective and novel adsorbent at thin-film solid-phase micro-extraction technique for the quick and concurrent extraction of five triazole fungicides in fruit and vegetable samples before quantitative analysis by high-performance liquid chromatography-ultraviolet. The incorporation of MnCo-layered double hydroxides with porous structure and abundant functional groups in a polymer medium improves the extraction efficiency of nanofibers owing to hydrogen bonding and π-π interactions formed between analytes and synthesized nano-adsorbent. Various important elements that affect the extraction efficiency of the intended analytes were optimized using a time-variable approach. Under the optimum conditions, the limit of detection and quantification range from 0.1 to 0.15 and 0.3–0.5 ng mL−1, respectively.

Determination of urinary androgens in women with polycystic ovary syndrome using LC-QqQ/MS and the application of thin film solid-phase microextraction (TF-SPME)

Hyperandrogenism is one of the most pronounced symptoms of Polycystic Ovary Syndrome (PCOS) and seems to play a key role in the pathogenesis of this complex disorder. Nevertheless, there is still a lack of consistent results regarding common steroid predictors of PCOS. Therefore, a liquid chromatography tandem mass spectrometry (HPLC-QqQ/MS) method was developed and validated to determine the concentrations of four classic androgens: androstenedione (An-dione), testosterone (T), 5α-dihydrotestosterone (DHT) and androsterone (An) in urine samples obtained from women with PCOS and healthy controls. The limits of detection were between 0.04 and 0.09 ng/mL, while the limits of quantification ranged from 0.1 to 0.3 ng/mL respectively. As a pre-treatment procedure prior to analysis, hydrolysis using β-glucuronidase and thin film solid-phase microextraction (TF-SPME) was applied. The methodology was employed to perform targeted metabolomics of urinary steroids in women with PCOS and healthy controls. All measured androgens: An-dione (p < 0.0001), T (p = 0.0001), DHT (p < 0.0001) and An (p = 0.0002) showed significantly higher concentrations in the urine of women with PCOS. The largest difference in the mean concentration was found for DHT, which was 2.8 times higher in the PCOS group (13.9 ± 14.1 ng/mg creatinine) in comparison to healthy controls (4.9 ± 3.4 ng/mg creatinine). The results of receiver operating characteristic curve indicated that determination of the panel of three urinary androgens: T+DHT+An-dione with, under the study assumptions, was the best predictor of PCOS diagnosis (AUC of ROC curve = 0.91 (95 % CI: 0.8212–0.9905). The application of an LC-MS/MS-based analysis, together with highly sensitive extraction techniques like TF-SPME, is a suitable approach to perform fast assays and obtain reliable results - crucial in the search for valuable and significant steroids predictors of PCOS.

Thin-film solid-phase microextraction of pesticides from cereal samples using electrospun polyvinyl alcohol/modified chitosan/porous organic framework nanofibers

In this study, a coating of electrospun polyvinyl alcohol/modified chitosan/hydroxy-containing porous organic framework (PVA/MCS/HC-POF) was fabricated and applied as a novel sorbent for thin-film solid-phase microextraction of pesticides from cereal samples, followed by HPLC-UV. The successful fabrication of PVA/MCS/HC-POF was confirmed through characterization tests. The functional group of MCS and a large number of hydroxyl groups on the HC-POF structure contributed to the co-extraction of pesticides. Under the optimum conditions, the calibration plots were linear within the range of 5.0–800 ng mL−1 (r2 ≥ 0.978), and the limits of detection were obtained below 4.0 ng mL−1. The method's precision was investigated through intra-day, inter-day, and film-to-film RSD (%) measurements, all of which were less than 6.5 %, 8.2 %, and 10.0 %, respectively. Furthermore, satisfactory recoveries ranging from 63.3 % to 79.0 % were obtained. Accordingly, the proposed method can be considered a suitable alternative for measuring trace amounts of pesticides in cereal samples.

Application of Sorbent-Based Extraction Techniques in Food Analysis.

This review presents an outline of the application of the most popular sorbent-based methods in food analysis. Solid-phase extraction (SPE) is discussed based on the analyses of lipids, mycotoxins, pesticide residues, processing contaminants and flavor compounds, whereas solid-phase microextraction (SPME) is discussed having volatile and flavor compounds but also processing contaminants in mind. Apart from these two most popular methods, other techniques, such as stir bar sorptive extraction (SBSE), molecularly imprinted polymers (MIPs), high-capacity sorbent extraction (HCSE), and needle-trap devices (NTD), are outlined. Additionally, novel forms of sorbent-based extraction methods such as thin-film solid-phase microextraction (TF-SPME) are presented. The utility and challenges related to these techniques are discussed in this review. Finally, the directions and need for future studies are addressed.

Hybrid materials based on deep eutectic solvents for the preconcentration of formaldehyde by SPME in coffee beverages

Coffee is one of the most widely consumed beverages. It can be prepared from green or roasted beans or from instant coffee. Unfortunately, in addition to the aroma obtained in the coffee roasting process, among others, formaldehyde can be produced. In this study, thin-film solid-phase microextraction was used to preconcentrate trace amounts of formaldehyde in different types of coffee with different roasting levels. For this purpose, 18 hybrid materials based on deep eutectic solvents were synthesized and tested as sorbents in thin-film solid-phase microextraction. The coffee samples were brewed, and then formaldehyde present in them was derivatized using the Nash reagent. The sample preparation procedure was optimized for selected DES-based sorbent using a central composite design method and validated. Formaldehyde was determined in almost all samples of second-crack coffee (roasted at 240 °C) at 0.17–0.75 ng mL−1 and in darker-colored instant coffees at 0.18–0.54 ng mL−1.

Thin films using the greenly prepared metal-organic framework MIL-100(Fe) and recycled polystyrene supported onto cellulose for the microextraction of personal care products from waters and cosmetics

The metal–organic framework MIL-100(Fe), prepared with a sustainable route, was integrated in recycled polystyrene for the preparation of thin film devices using cellulose paper as support. The resulting device was used in a thin film solid-phase microextraction method (TF-SPME) in combination with high performance liquid chromatography and photodiode array detection (HPLC-PDA) for determining 7 personal care products (PCPs) in cosmetics and swimming pool waters. A thorough optimization was performed during the preparation of the devices, studying the MOF loading and the number of layers of MIL-100(Fe)/PS supported over the cellulose paper for the TF device, together with proper optimization of several analytical microextraction aspects, such as the extraction mode and the nature of the desorption solvent. Besides, an experimental design 2k with two levels and 3 factors was applied for the optimization of the remaining parameters of the method, namely extraction time, volume of the desorption solvent, and desorption time. The entire TF-SPME-HPLC-PDA method showed adequate analytical performance features, with limits of detection down to 7.5 µg·L-1 and intermembrane precision values lower than 11 % (checked intra-day) and 19 % (checked inter-day). Several cosmetics and swimming pool waters were successfully analyzed, thus demonstrating the applicability of these thin film devices in complex samples. Besides, the proposed method was assessed by applying the main green metrics currently used.

Keggin-type polyoxometalate embedded polyvinylidene fluoride for thin film microextraction of organophosphorus pesticides.

The present research is the first report on the application of Keggin-type phosphotungstic acid/polyvinylidene fluoride membrane. This compound as a simple, cost-effective and novel sorbent was used for the extraction and pre-concentration of two organophosphorus pesticides in real samples in the thin film solid-phase microextraction (TFME) method. TFME as one of the sub-branches of solid phase microextraction resolves the problems of SPME methods, including their limited absorption capacity. These extraction methods have a high surface-to-volume ratio, which improves their sensitivity compared to other geometries. Under optimal conditions, the limit of detections (LODs), the limit of quantifications (LOQs), and relative standard deviation (RSD) of this method varied in the ranges of 0.29-0.31μg L-1, 0.96-1.0μgL-1, and 3.9%-6.2%, respectively. This method showed a linear dynamic range (LDR) of 1.0-500μgL-1 with a coefficient of determination (r2) above 0.9978. This promising method was used to analyze malathion and diazinon.

Growth of bimetallic Ni-Co MOFs on a skeleton of electrospun PAN nanofibers and coating on a thin film for SPME of amitriptyline and nortriptyline in urine and plasma samples

In this research, composited bimetallic organic framework-polyacrylonitrile (Ni-Co MOFs-PAN) was applied for thin-film solid phase microextraction (TF-SPME) of tricyclic antidepressant (TCA) drugs from biological samples. The separation and quantification of the analytes were accomplished by HPLC-UV. First, seeded nanofibers with organic ligands were electrospun on a sheet of foil. Then, with the uniform in-situ solvothermal growth of Ni-Co MOFs on the skeletal surface of nanofibers, the nanoparticles were successfully attached to the surfaces without effective bonds and produced a thin layer with a high flexibility, large active surface and abundant functional groups for adsorption. The characteristics of the produced nanocomposite were investigated by Fourier-transform infrared spectroscopy, field emission-scanning electron microscopy, X-ray diffraction, energy dispersive X-ray spectroscopy and Brunauer-Emmett-Teller analysis. The stirring rate, pH, ionic strength, adsorption and desorption time along with type and volume of desorption solvents as influential factors on extraction efficiencies of the analytes, were optimized by one variable at a time method. Under optimized conditions, wide linear range for analytes in water and plasma matrices were obtained from 0.2 to 1000.0 μg L−1 and 1.0–1000.0 μg L−1, respectively, with R2 ≥ 0.9925. The limits of detection were in the range of 0.06–0.3 μg L−1 in different media. Good repeatability and reproducibility were attained within intra-day, inter-day and film-to-film RSDs% (n = 3) below 3.3 %, 3.9 % and 4.7 %, respectively. Since desirable relative recoveries were calculated between 91.4 % and 100.4 %. The method can be used for the successful extraction and measurement of amitriptyline and nortriptyline as its metabolite in different sampling time from urine and plasma matrices.

Cold atmospheric plasma treated 3D printed polylactic acid film; application in thin film solid phase microextraction of anticancer drugs

Tyrosine Kinase Inhibitors (TKIs) represent a pharmacological category of targeted therapeutics deployed for the treatment of malignant pathologies. Considering the side effects of this class of drugs for humans, therapeutic drug monitoring (TDM) becomes important. Here, a novel and specific methodology is introduced for the quantification of two TKIs (dasatinib and erlotinib) in human plasma samples. Furthermore, this study investigates the successful application of 3D printer technology in analytical sample preparation methods. Employing a fused deposition modeling (FDM) 3D printer and polylactic acid (PLA) filament, adsorbent films were designed and produced to be utilized in thin film microextraction. The 3D printed polylactic acid film surface was modified using cold atmospheric plasma (CAP) as a fast, clean and dry surface modification method with low consumption of chemicals and energy. Subsequently, FESEM, AFM, ATR-FTIR, and WCA analysis studies were employed to effectively assess the efficacy of the plasma surface modification method for the 3D printed films. After the optimization of the plasma modification and extraction methods, human plasma samples were studied for the effectiveness of the aforementioned approach. So, the selected 3D printed films with excellent microextraction efficiency have been found to be effective in sample preparation of biological samples. The linear dynamic range (LDR), limit of detection (LOD) and limit of quantification (LOQ) were obtained 0.10–20 μgL-1, 0.03 μgL−1and 0.1 μgL−1 for dasatinib and 1.0–500 μgL-1, 0.3 μgL−1, and 1 μgL−1 for erlotinib. The results obtained indicate that the developed method proves to be successful in the effective separation of anticancer drugs.

Polyaniline-silica doped with oxalic acid as a novel extractor phase in thin film solid-phase microextraction for determination of hormones in urine.

In this study, different polyanilines were synthesized and evaluated for the determination of three hormones, including 17-β-estradiol, 17-α-ethinylestradiol, and estrone,in urine using a novel methodology based on thin film solid-phase microextraction technique, employing the sampling well plate system. The extractor phases, designated as polyaniline doped with hydrochloric acid, polyaniline doped with oxalic acid, polyaniline-silica doped with hydrochloric acid, and polyaniline-silica doped with oxalic acid, were characterized by electrical conductivity measurements, scanning electron microscopy, and Fourier transform infrared spectroscopy. The optimized extraction conditions were composed of 1.5 mL of urine and pH adjusted to 10, with no need to dilute sample and the desorption step, 300μL of acetonitrile was used. The calibration curves were performed in the sample matrix, with detection and quantification limits ranged from 0.30 to 3.03μg L-1 and from 1.0 to 10.0μg L-1 , respectively, with r ≥ 0.9969. The relative recoveries ranged from 71% to 115%, and intraday precision showed values ≤12% and interday ≤20%. The applicability of the method was successfully evaluated, and six urine samples from female volunteers were analyzed. The analytes were not detected or were below the limits of quantification in these samples.

Development of electrospun nanofibers based on Poly (vinyl alcohol) for thin film solid-phase microextraction of antidepressant drugs in biological samples

Today, antidepressants are widely used and it is important to determine their trace amounts due to harmful consequences. Here, a new nano sorbent was reported for the simultaneous extraction and determination of three types of antidepressant drugs (Clomipramine (CLO), Clozapine (CLZ), and Trimipramine (TRP) by the thin-film solid-phase micro-extraction (TFME-μSPE) method followed by the Gas Chromatography-flame ionization detector (GC-FID) analysis. So, the compound poly (vinyl alcohol) (PVA)/citric acid(CA)/β-cyclodextrin/Bi2S3@g-C3N4 nano sorbent was constructed by electrospinning technique. Then, nano sorbent was studied to optimize the many parameters impacting the extraction performance. Electrospun nanofiber has a large surface area, high porosity, and homogeneous morphology with a uniform bead-free structure. In optimal conditions, the limits of detection and quantification were calculated to be 0.15–0.03 ng mL−1 and 0.5–0.1 ng mL−1, respectively. The dynamic linear range (DLR) was in the range of 0.1 to 1000 ng mL−1 for CLO and CLZ, and 0.5 to 1000 ng mL−1 for TRP with correlation coefficients (R2) of 0.999. The relative standard deviations (RSDs) were achieved in the range of 4.9–6.8% (intra-day, n = 4) and 5.4–7.9% (inter-day, n = 3) in the period of 3 days. Finally, the capability of the method was evaluated to simultaneously measure trace amounts of antidepressants aqueous sample with desirable extraction efficiency (78 to 95%).

Development of the thin film solid phase microextraction (TF-SPME) method for metabolomics profiling of steroidal hormones from urine samples using LC-QTOF/MS.

In the present study, the development and optimization of a thin film solid phase microextraction method (TF-SPME) was conducted for metabolomics profiling of eight steroid compounds (androsterone, dihydrotestosterone, dihydroepiandrosterone, estradiol, hydroxyprogesterone, pregnenolone, progesterone and testosterone) from urine samples. For optimization of extraction method, two extraction sorbents (PAN-C18 and PS-DVB) were used as they are known to be effective for isolation of low-polarity analytes. The stages of sample extraction and analyte desorption were considered as the most crucial steps in the process. Regarding the selection of the most suitable desorption solution, six different mixtures were analyzed. As a result, the mixture of ACN: MeOH (1:1, v/v) was chosen in terms of the highest analytes' abundances that were achieved using the chosen solvent. Besides other factors were examined such as the volume of desorption solvent and the time of both extraction and desorption processes. The analytical determination was carried out using the ultra-high performance liquid chromatography coupled with high resolution tandem mass spectrometry detection in electrospray ionization and positive polarity in a scan mode (UHPLC-ESI-QTOF/MS). The developed and optimized TF-SPME method was validated in terms of such parameters as extraction efficiency, recovery as well as matrix effect. As a result, the extraction efficiency and recovery were in a range from 79.3% to 99.2% and from 88.8% to 111.8%, respectively. Matrix effect, calculated as coefficient of variation was less than 15% and was in a range from 1.4% to 11.1%. The values of both validation parameters (recovery and matrix effect) were acceptable in terms of EMA criteria. The proposed TF-SPME method was used successfully for isolation of steroids hormones from pooled urine samples before and after enzymatic hydrolysis of analytes.

Development of a polyurethane-coated thin film solid phase microextraction device for multi-residue monitoring of pesticides in fruit and tea beverages.

A novel solid-phase microextraction device coated with an efficient and cheap thin film of polyurethane was developed for trace determination of 13 widely used pesticides in fruit and tea beverages. A round-shaped polyurethane film covering the bottom of a glass vial was fabricated as the sorbent to exhibit a superior capacity for preconcentrating target compounds and reducing matrix interferences. After optimization of the key parameters including the film type, extraction time, solution pH, ionic strength, desorption solvent, and conditions, this device allowed an efficient adsorption-desorption cycle for the pesticides accomplished in one vial. Coupled with gas chromatography-electron capture detection, the polyurethane-coated thin film microextraction method was successfully established and applied for the analysis of real fruit and tea drinks, showing low limits of detection (0.001-0.015μg/L), wide linear ranges (1.0-500.0μg/L, r2 >0.9931), good relative recoveries (77.2%-106.3%) and negligible matrix effects (86.1%-107.5%) for the target pesticides. The proposed approach revealed strong potential of extending its application by flexibly modifying the type or size of the coating film. This study provides insights into the enrichment of contaminants from complex samples using inexpensive and reusable microextraction devices that can limit the environmental and health impact of the sample preparation protocol.

Development of a green deep eutectic solvent-based thin film solid phase microextraction technique for the preconcentration of chlorophenoxy acid herbicides in drainage ditches and river waters using a central composite design

Herbicides are chemicals commonly used for the control of the environment’s biodiversity. Many of them are soluble in water, thus they end up as water contamination. It is necessary to establish an analytical technique that can accurately measure the level of concentration of pollutants in water samples, while being time efficient, inexpensive and easy. Moreover, it is important for that technique to be green and sustainable.In this paper, the thin film solid phase microextraction (TF-SPME) technique is proposed with the use of a deep eutectic solvent (DES) as a novel sorbent. DES was a mixture of trihexyl(tetradecyl)phosphonium chloride: octadecanoic acid in a 1:2 M ratio. Stainless steel mesh was used as a support for DES sorbent. Concentrations of chlorophenoxy acid herbicides 3,6-dichloro-2-methoxybenzoic acid (DC), 2-methyl-4-chlorophenoxyacetic acid (MCPA), and 2-methyl-4-chlorophenoxypropionic acid (MCPP) were measured. To select the optimal extraction conditions, five factors such as volume of samples, amount of salt, extraction time, desorption time, and pH of samples were tested in the central composite design. According to the analysis of statistical data (Statistica), the volume and the pH of the sample were significant factors. By using DES sorbent on a mesh support, the determined herbicides were preconcentrated in samples DC 69 times, MCPA 65 times, and MCPP 71 times, respectively. Samples were taken from drainage ditches and rivers located close to farmland. The analysis was performed with the use of the HPLC-UV technique. The presence of DC and MCPA was found in two out of five samples, in amounts of 22.4 ng mL−1 and 40.3 ng mL−1. The presence of MCPP was not detected in any of the analyzed samples. Due to the high recovery (72–94 %) and precision (as RSD, 3.2–11.1 %), the developed method can be successfully used for the preconcentration and determination of chlorophenoxy acid herbicides.

Preparation of electrospun polyacrylonitrile/ϒ-cyclodextrin metal–organic framework nanofibers for extraction of multi-classes herbicides from cereal samples before HPLC-UV analysis

This study employed thin-film solid-phase microextraction procedure as a simple, sensitive, green, and solvent-free method for the co-extraction of multi-classes herbicides from cereal samples before HPLC-UV analysis. To provide an efficient sorbent, electrospun nanofibers of the crosslinked polyacrilonitril/ϒ-cyclodextrin-metal–organic framework (PAN/ϒ-CD-MOF) were successfully fabricated and assessed as a new thin-film adsorbent. Under the optimal conditions (desorption solvent: acetonitrile, desorption time: 5 min, sample solution pH: 7.0, salt concentration: 15% (w/w), and extraction time: 15 min), good linearity in the range of 2.5–1250.0 ng/mL (r2 ≥ 0.992) was obtained. The detection limits were 0.75–2.50 ng/mL. The extraction recoveries and relative recoveries were 64.9–75.7% and 92.9–106.1%, respectively. The method showed good precision as the relative standard deviations were ≤ 6.3%. Finally, the developed method was applied efficiently for trace analysis of the herbicides in wheat, rice, and barley samples. Generally, the proposed method provided a simple, sensitive, environmentally friendly, and relatively fast approach.

Deep Eutectic Solvent-Based Coating Sorbent for Preconcentration of Formaldehyde by Thin-Film Solid-Phase Microextraction Technique

A thin-film solid-phase microextraction method with a sorbent composed of a deep eutectic solvent was developed for the preconcentration of formaldehyde from river and lake water samples. Four new deep eutectic solvents (DESs) were synthesized, each in molar ratios 1:1, 1:2, and 1:3. Among prepared compounds, the greatest efficiency in the proposed method of preconcentration of formaldehyde derivatized with Nash reagent was demonstrated by DES-3 consisting of benzyldimethylhexadecylammonium chloride and lauric acid, in a molar ratio of 1:3. For the proposed method, the parameters affecting the extraction efficiency of formaldehyde were optimized (including the choice of DES-based sorbent and desorption solvent as well as the sample volume and pH, the salting-out effect, the extraction time, and the desorption time). Under optimal conditions, the proposed method achieved good precision between 3.3% (for single sorbent) and 4.8% (for sorbent-to-sorbent) as well as good recovery ranging from 78.0 to 99.1%. The limits of detection and quantitation were 0.15 ng mL−1 and 0.50 ng mL−1, respectively. The enrichment factor was equal to 178. The developed method was successfully applied to determine formaldehyde in environmental water samples.

Sequential thin film-solid phase microextraction as a new strategy for addressing displacement and saturation effects in food analysis

Solid-phase microextraction (SPME) is robust, selective, sensitive, and can be automated. However, low extraction phase to sample volume ratio sometimes results in saturation, competition, or swelling phenomena in complex samples. A sequential extraction method using two thin-film SPME (TF-SPME) devices with different selectivities was developed. The sequential application of the thin films provided higher extraction capacities, while avoiding swelling, saturation, and displacement effects, and enabled the quantitative determination of all compounds in the analyzed samples, independent of their polarity and affinity to extraction phases. In the first step, a TF-SPME device with a poly(dimethylsiloxane) (PDMS) coating was used to deplete non-polar and other compounds present at high concentrations in the sample, which are typically associated with the undesirable phenomena. In the second step, a TF-SPME device coated with a combination of hydrophobic/lipophilic balanced (HLB) particles and PDMS (HLB/PDMS) was applied for the direct microextraction of the remaining compounds, including polar compounds left over after the first step. The proposed method resulted in decreased levels of interference and yielded encouraging analytical data for beer samples.

A polydimethylsiloxane/deep eutectic solvent sol-gel thin film sorbent and its application to solid-phase microextraction of parabens

A novel, efficient and reproducible thin-film solid-phase microextraction method using the polydimethylsiloxane/deep eutectic solvent sol-gel as coating material was developed for preconcentration of parabens from environmental samples.New sorbent materials consisting of polydimethylsiloxane with nine new synthesized deep eutectic solvents were prepared by the sol-gel method, and these materials were used to prepare thin film coatings on a mesh support. Among obtained compounds, the highest efficiency in the extraction of parabens was demonstrated by a sorbent consisting of trihexyltetradecylphosphonium chloride and n-docosanol in a molar ratio 1:2 mixed with polydimethylsiloxane.For the proposed method, the parameters affecting the extraction efficiency of parabens were optimized, including the coating material type based on polydimethylsiloxane/deep eutectic solvent, the sample volume, the salting-out effect, the pH of the sample, the extraction time, the desorption solvent and time. The limits of detection and quantitation were from 0.023 to 0.062 ng mL−1 and 0.076–0.201 ng mL−1, respectively, and the enrichment factors ranged from 174 to 186. Under optimal conditions, the proposed method based on measurements for river and lake water achieved good precision between 2.7 and 5.9% and recovery ranging from 79.1 to 88.1%. The developed method was successfully applied to determine trace levels of parabens in the samples of surface waters collected from rivers and lakes.

Development of novel thin-film solid-phase microextraction materials based on deep eutectic solvents for preconcentration of trace amounts of parabens in surface waters.

A green and sensitive thin-film solid-phase microextraction method based on deep eutectic solvent was developed that enables simultaneous isolation, preconcentration, and determination of parabens in surface waters. Six new deep eutectic solvents were synthesized and used directly to prepare thin-film coatings on a stainless steel mesh support. Among the compounds obtained, the highest efficiency in the extraction of parabens was found for a material consisting of trihexyltetradecylphosphonium chloride and n-docosanol in a molar ratio of 1:2. For the proposed method, parameters affecting the extraction efficiency of parabens, such as the coating material, the desorption solvent, the volume of the sample, the pH of the sample, the extraction and desorption time, and the salting-out effect, were optimized. Under optimal conditions, the proposed method allowed us to achieve good precision between 3.6 and 6.5% and recovery ranging from 68.1 to 91.4%. The limits of detection range from 0.018 to 0.055ng/mL.