Dispersive liquid–liquid microextraction-assisted by deep eutectic solvent for the extraction of different chlorophenols from water samples followed by analysis using gas chromatography-electron capture detection

Development of a Paper-Based Disposal Thin-Film Solid-Phase Microextraction Tool for the Quantification of Environmentally Hazardous 4-Chlorophenol in Water

The presence of chlorinated compounds in water resources presents various environmental and health risks. Therefore, there is a precise need to develop a potential technique for fast and efficient monitoring of chlorinated contaminants in water due to environmental protection and regulation compliance. Here, we designed a paper-based thin-film solid-phase microextraction (TF-SPME) patch to estimate 4-chlorophenol (4-CRP), a widely known environmentally hazardous pollutant in water samples. We fabricated the microextraction patch on the paper support utilizing the thin film applicator for uniform coating using divinylbenzene, polydimethylsiloxane, and a multiwalled carbon nanotube (MW-CNT) composite recipe. To check the performance of our fabricated tool, we directly exposed the TF-SPME patches to standard solutions with various concentrations of 4-CRP in water and finally quantified the analyte by exploiting the gas chromatography-mass spectrometer. Our experiments demonstrated the high extraction efficiency of the paper-based TF-SPME analytical tool for the estimation of 4-CRP in water with a limit of detection of ∼10 ng/mL, suggesting the practical applicability of the technique to monitor the analyte within the recommended range. To check the feasibility of the proposed technique for rapid determination, we performed the calibration curve of the analyte in the concentration range of 100-10,000 ng/mL and finally derived the curve fitting equation for the estimation of an unknown amount of 4-CRP. This study demonstrated the feasibility of using a simple paper-based thin-film solid-phase microextraction patch as a sampling kit for monitoring the environmentally hazardous 4-CRP pollutant from water. In the future, the proposed analytical method may be useful for the rapid quantification of chlorinated compounds from the water matrix.

Chlorophenols in environment: Recent updates on pretreatment and analysis methods

Chlorophenols (CPs) are widely used in industries such as petrochemicals, insecticides, pharmaceuticals, synthetic dyes and wood preservatives. However, owing to the improper discharge and disposal, they have become major contaminants that are ubiquitously distributed in water, soil, and sewage sediments, posing a significant threat to ecosystems and human health. Consequently, accurate, sensitive and effective pretreatment and analysis methods for CPs are urgently required and have been actively explored in recent years. This review encompasses the pretreatment and detection methods for CPs in environmental samples from 2010 to 2024. The pretreatment methods for CPs primarily include solid-phase extraction, liquid-liquid extraction, solid-phase microextraction, liquid-phase microextraction, and QuEChERS. These methods are evolving towards more effective and environmentally friendly technologies, such as the miniaturization and automation of equipment, the development of innovative materials (including graphene, molecularly imprinted polymers, layered double hydroxides, porous organic polymers, and porous carbon), and the use of green solvents like deep eutectic solvents. Detection methods emphasize liquid chromatography-mass spectrometry, gas chromatography-mass spectrometry, sensors, and capillary electrophoresis. Advances in chromatographic columns, novel ion sources, and high-resolution mass spectrometry have significantly improved detection performance. In addition, the pros and cons of diverse techniques, critical comments and future perspectives are elaborated.

Spectrophotometric determination for green hydrophobic deep eutectic solvent-based microextraction of Brilliant Blue FCF (E133) from beverages

In this study, a simple, sensitive, and rapid method called green hydrophobic deep eutectic solvent-based liquid-liquid microextraction was developed to extract Brilliant Blue FCF dye from beverages. This method utilizes hydrophobic DES obtained by forming tetrabutylammonium bromide and 1-octanol in a 1:5 ratio as green extraction solvent. The transition of Brilliant Blue FCF to the DES phase occurred on its own, without the need for any reagents such as added salt or tetrahydrofuran. Several crucial factors were tried to get the best extraction efficiency, including species, DES volume and molar ratio, solution pH, ultrasonication, and centrifugation time. Under optimum conditions, extraction recoveries were achieved in the range of 95.1-101.3 % with the method developed for Brilliant Blue FCF. The detection and determination limits were observed to be 4.1 μg l-1 and 12.1 μg l-1, respectively. In addition, the relative standard deviation values for the method's accuracy were found to be 2.23 % and 3.48 % within and between days, respectively. It has been established that the developed method is highly environmentally friendly thanks to the application of the Analytical GREENness (AGREE) and Green Analytical Procedure Index (GAPI) tools. This study shows that DES applications can be carried out without the use of emulsifiers and dispersants by prioritizing the use of hydrophobic DES compounds as environmentally friendly and green extraction solvents in food samples.

Magnetic multi-template molecularly imprinted polymers for selective simultaneous extraction of chlorophenols followed by determination using HPLC

Magnetic multi-template molecularly imprinted polymers (M-mt-MIPs) were successfully synthesized by surface imprinting and multi-template imprinting strategy, using polydopamine coated magnetic multi-walled carbon nanotubes as supporting materials, five typical chlorophenols (CPs) as templates, methacrylic acid as functional monomer and ethylene glycol dimethacrylate as cross-linker. Compared to non-imprinted polymers (NIPs), the as-prepared M-mt-MIPs showed high adsorption capacity (32.58‒80.63 mg g-1), rapid mass transfer and specific selectivity for the five targeted CPs, which were applied as magnetic solid-phase extraction (MSPE) adsorbents. Parameters affecting MSPE efficiency were detailed investigated, such as adsorbents dosage, sample pH, extraction time, type and volume of desorption solvent and salt effect. Combined with HPLC-DAD, a simple, rapid and sensitive method was established, showing good linearity (2‒200 μg L-1), low limits of detection (0.32‒0.49 μg L-1), and high enrichment factors (35.2‒108). The developed M-mt-MIPs-MSPE-HPLC method was applied to enrich and determine CPs in tannery wastewater, wet-blue and crust leather, and satisfactory spiking recoveries were attained in the range of 73.95‒109.7% with relative standard deviations (RSDs) of 2.13-8.48%. This study provided a new alternative material and method to rapid simultaneously extract and analyze low concentration of typical CPs in complicated matrices.

Determination of copper ion at trace levels in apple tea samples by simultaneous complexation and spray assisted microextraction method prior to detection by flame atomic absorption spectrophotometry

In the present study, a green and sensitive analytical method for the determination of copper ion at trace levels in apple tea samples was developed. Simultaneous complexation/extraction of the analyte were achieved by spraying-based fine droplet formation liquid-phase microextraction (SFDF-LPME). Copper ion was complexed with a Schiff base chelating agent called as N,N'-Bis(salicylidene)-1,2-phenylenediamine (BSP). Under the optimum conditions, the developed SFDF-LPME-FAAS and FAAS system were assessed with respect to limit of detection (LOD), limit of quantitation (LOQ), linearity and percent relative standard deviation (%RSD). LOD and LOQ values for SFDF-LPME-FAAS method were found to be 6.0 and 19.9 µg/kg, respectively. Enhancement in calibration sensitivity for developed method was found as 23 folds. In addition, accuracy/suitability of the developed SFDF-LPME-FAAS method were confirmed by spiking experiments. Two different apple tea samples were spiked to different concentration values and percent recovery results from 91.1 and 123.8 % proved the accuracy/suitability of the method.

Deep eutectic solvents for the determination of endocrine disrupting chemicals

The harmful effects of endocrine disrupting chemicals (EDCs) to humans and other organisms in the environment have been well established over the years, and more studies are ongoing to classify other chemicals that have the potential to alter or disrupt the regular function of the endocrine system. In addition to toxicological studies, analytical detection systems are progressively being improved to facilitate accurate determination of EDCs in biological, environmental and food samples. Recent microextraction methods have focused on the use of green chemicals that are safe for analytical applications, and present very low or no toxicity upon disposal. Deep eutectic solvents (DESs) have emerged as one of the viable alternatives to the conventional hazardous solvents, and their unique properties make them very useful in different applications. Notably, the use of renewable sources to prepare DESs leads to highly biodegradable products that mitigate negative ecological impacts. This review presents an overview of both organic and inorganic EDCs and their ramifications on human health. It also presents the fundamental principles of liquid phase and solid phase microextraction methods, and gives a comprehensive account of the use of DESs for the determination of EDCs in various samples.

One-step preparation of carboxyl-functionalized porous organic polymer as sorbent for enrichment of phenols in bottled water, juice and honey samples

Herein, a novel carboxyl-functionalized porous organic polymer (COOH-POP) was prepared as sorbent. Due to multiple hydrogen bonds and π-π interactions between COOH-POP and phenols, COOH-POP shows good enrichment ability and very fast adsorption rate for phenols. Then, an analytical method was developed for determination of five phenols (2-chlorophenol, bisphenol A, 2,6-dichlorophenol, 2,4-dichlorophenol and p-tert-butylphenol) in bottled water, lemon juice, peach juice and honey samples using COOH-POP as solid phase extraction sorbent in combination with high performance liquid chromatography. Under optimal conditions, the COOH-POP based method gave the detection limits (S/N = 3) of 0.02-0.10 ng mL-1 for bottled water, 0.03-0.12 ng mL-1 for lemon juice, 0.03-0.25 ng mL-1 for peach juice and 0.7-1.5 ng g-1 for honey samples. The recoveries for spiked samples ranged from 84.0 % to 119.0 % with relative standard deviation less than 7.6 %. This study provides a new yet effective method for enrichment of phenols by designing carboxyl-functionalized porous organic polymer as sorbent.

Microextraction of Tigecycline Using Deep Eutectic Solvents and Its Determination in Milk by LC-MS/MS Method

The occurrence of tigecycline (TGC), a new first glycylcycline antibiotic residues in food products harmfully influences potential human consumers health. Therefore, analysts are forced to develop new microextraction methods connected with modern extractants for effective isolation of this compound. For this purpose, deep eutectic solvents (DES) as the extraction media were used. Liquid-liquid microextraction (LLME) of tigecycline from milk samples with application of the hydrophobic deep eutectic solvents: decanoic acid:thymol (1:1), thymol:camphor (2:1), dodecanoic acid:menthol (2:1), and dodecanoic acid:dodecanol (1:1) was developed. The studied samples were subjected to a deproteinization process using trichloroacetic acid solution and acetonitrile. The optimal microextraction parameters, molar ratio of DES components, amount of extraction solvents, pH of milk sample, shaking, and centrifugation time, were chosen. Tigecycline in the obtained microextracts of deep eutectic solvents was analyzed using a liquid chromatographic technique connected with a tandem mass spectrometry (LC-MS/MS) system. The limits of detection and quantification values for TGC determination followed by DES-LLME-LC-MS/MS method were in the 1.8 × 10^-11 mol L^-1 (0.01 μg kg^-1) to 4.0 × 10^-9 mol L^-1 (2.28 μg kg^-1) and 5.5 × 10^-11 mol L^-1 (0.03 μg kg^-1) to 1.2 × 10^-8 mol L^-1 (6.84 μg kg^-1) ranges, respectively. The RSD values of precision were in the range 1.4-7.8% (intraday) and 5.4-11.7% (interday). The developed procedures were used for the determination of tigecycline in different bovine milk samples.

An Environmental-friendly Procedure Based on Deep Eutectic Solvent for Extraction and Determination of Toxic Elements in Fish Species from Different Regions of Iraq

In this study, an eco-friendly procedure was established by vortex-assisted liquid-phase microextraction based on deep eutectic solvent (VA-LPME-DES) combined with graphite furnace atomic absorption spectroscopy (GFAAS). The performance of this method was demonstrated by the extraction and analysis of lead (Pb), cadmium (Cd), and mercury (Hg) in fish samples. The hydrophobic DES is considered as a green extractant (environmentally friendly and less toxic than common organic solvents) and is a suitable alternative to common toxic organic solvents and is made of l-menthol and ethylene glycol (EG) with a molar ratio of 1:1. Under optimized conditions, the method linearity was in the ranges of 0.15-150 µg kg-1 with the coefficient of determinations (r2) higher than 0.996. Accordingly, the detection limits for Pb, Cd, and Hg were 0.05, 0.05, and 0.10 µg kg-1, respectively. The analysis of fish samples showed that the concentration of toxic elements in fish caught from the Tigris and Euphrates Rivers is much higher than the concentration of these elements in locally farmed trout fish. Also, the analysis of fish-certified reference materials with presented procedure produced results that were in good agreement with the certified values. The results showed that VA-LPME-DES is a very cheap, fast, and environmental-friendly procedure for the analysis of toxic elements in different types of fish species.

Extraction of parabens from personal care products using a pH-responsive hydrophobic deep eutectic solvent: experimental design and COSMO-RS evaluations

A pH-responsive hydrophobic deep eutectic solvent is used for the extraction of parabens from different personal care products.