Dispersive Liquid-liquid Microextraction Research Articles

Digital colorimetric detection of ammonium in water samples after microextraction procedure using deep eutectic solvent, based on DLLME method

In this study, we have presented a simple, cost-effective, and efficient method for quantifying ammonium ions based on digital colorimetry using a smartphone. Firstly, ammonium ions are converted into a yellow-colored derivative in an alkaline medium in the presence of acetylacetone and formaldehyde. Then, the colored compound is extracted using the dispersive liquid–liquid microextraction (DLLME) technique and its color intensity was measured using a smartphone as RGB Color Detector. For this purpose, a novel deep green eutectic solvent including tetrapropylammonium bromide (TPABr) and 3-methyl-1-butanol (isoamyl alcohol) was employed, with a molar ratio of 1:6. The impact of key variables on the derivatization and microextraction processes, including solution pH, concentration of acetylacetone and formaldehyde, temperature, reaction time, and extraction solvent volume, was thoroughly investigated and optimized. In the optimized conditions, the method was found to be linear in the range of 0.15–5.00 µg mL−1 with a limit of detection of 0.05 µg mL−1 (S/N = 3). Moreover, the proposed method was successfully applied for the determination of ammonium ions in environmental water samples, fish pond, and aquarium water samples, with recoveries ranging from 94.7 to 106.7 %.

Comparative study of sample preparation procedures to determine the main compounds in ayahuasca beverages by QuEChERS and high-performance liquid chromatography analysis.

Ayahuasca is a psychoactive drink originally consumed by indigenous people of the Amazon. The lack of regulation of this drink leads to uncontrolled consumption, and it is often consumed in religious contexts. The aim of this work is to compare three miniaturised extraction techniques for extracting the main ayahuasca compounds from beverages. Three sample pretreatment techniques were evaluated (dispersive liquid-liquid microextraction [DLLME], microextraction by packed sorbent [MEPS] and QuEChERS [Quick, Easy, Cheap, Effective, Rugged and Safe]) for the simultaneous extraction of N,N-dimethyltryptamine (DMT), tetrahydroharmine (THH), harmine, harmaline, harmol and harmalol from ayahuasca beverage samples. Then, the most promising technique (QuEChERS) was chosen to pre-concentrate the analytes, subsequently detected by high-performance liquid chromatography coupled to a diode array detector (HPLC-DAD). The procedure was optimised, with the final conditions being 500 μL of extractor solvent, 85 mg of primary secondary amine (PSA) and 4s of vortexing. The analytical method was validated, showing to be linear between 0.16 and 10μg/mL for β-carbolines and between 0.016 and 1μg/mL for DMT, with coefficients of determination (R2) between 0.9968 and 0.9993. The limit of detection (LOD) and lower limit of quantification (LLOQ) were 0.16 μg/mL for all compounds, except for DMT (0.016 μg/mL) and extraction efficiencies varied between 60.2% and 88.0%. The analytical methodology proved to be accurate and precise, with good linearity, LODs and LLOQs. This method has been fully validated and successfully applied to ayahuasca beverage samples.

Determination of insecticide residues in beverages based on MIL-100(Fe) dispersive solid-phase microextraction in combination with dispersive liquid-liquid microextraction followed by HPLC-MS/MS

A novel dispersive solid-phase microextraction method based on a metal-organic framework (MIL-100(Fe)) combined with a dispersive liquid-liquid microextraction technique was proposed for the extraction and enrichment of four insecticides in beverages. The qualitative and quantitative analysis of these insecticides was conducted using HPLC-MS/MS. To optimize the extraction process, several parameters were investigated, and the main variables were optimized using CCD-based RSM. The developed method displayed a wide linear range of 1.000–1000 ng/L and R2 values >0.993 for all four calibration curves. The method demonstrated high sensitivity, with LODs and LOQs of 0.3–0.6 ng/L and 0.8–1.0 ng/L, respectively. In addition, the greenness of the proposed method was assessed using the Complex GAPI tool, and the results showed that the proposed method exhibits benefits, such as minimal usage of organic solvents and negligible matrix influence, making it a suitable method for the detection of insecticide residues in beverages.

Analytical strategy to assess the microbial degradation of poly(butylene-adipate-co-terephthalate)/poly(lactic acid) films

Plastic is widely used in agricultural applications, but its waste has an adverse environmental impact and a long-term detrimental effect. The development of biodegradable plastics for agricultural use is increasing to mitigate plastic waste. The most commonly used biodegradable plastic is poly(butylene adipate co-terephthalate)/poly(lactic acid) (PBAT/PLA) polymer.In this study, an analytical procedure based on dispersive liquid-liquid microextraction (DLLME) followed by gas chromatography-mass spectrometry (GC-MS) in combination with chemometrics has been optimized to assess the degradation level of PBAT/PLA films by monitoring their characteristic degradation products. Carboxylic acids (benzoic, phthalic, adipic, heptanoic, and octadecanoic acids) and 1,4-butanediol have been found to be potential markers of PBAT/PLA degradation.The DLLME-GC-MS analytical approach has been applied for the first time to assess the degradation efficiency of several microorganisms used as degradation accelerators of PBAT/PLA based on the assigned potential markers. This analytical strategy has shown higher sensitivity and precision than standard techniques, such as elemental analysis, allowing us to detect low degradation levels.

Ultrasound-Assisted Extraction Combined with Low-Density Solvent-Based Dispersive Liquid-Liquid Microextraction as an Efficient and Sensitive Method for the Determination of Clodinafop-Propargyl Herbicide in Wheat Samples

Ultrasound-Assisted Extraction Combined with Low-Density Solvent-Based Dispersive Liquid-Liquid Microextraction as an Efficient and Sensitive Method for the Determination of Clodinafop-Propargyl Herbicide in Wheat Samples

New fabric phase sorptive extraction for nondestructive analysis of heritage textile samples

Several types of pesticides used in museum collections over time become dangerous for people who may handle textile articles treated with such substances. In the case of the analysis of ancient, modern, and contemporary textile materials, it is particularly important to keep the artifacts intact, as they cannot be replaced. The need to use micro- or nondestructive techniques led to the development of methods such as solid-phase microextraction (SPME), liquid‒liquid dispersive microextraction (DLLME), and single-droplet microextraction (SDME). In this paper is described an optimized extraction method of three pesticides (malathion, methoxychlor, and permethrin) by creating a non-destructive solid phase extraction system on a textile support, abbreviated FPSE – 100 % cotton fabric coated with a sol-gel solution prepared from a polymer (PEG or PDMS). To obtain a suitable FPSE, the following parameters were evaluated: polymer selection (individual or mixture of polymers), acid catalyst (trifluoroacetic acid, acetic acid and hydrochloride acid), amount of polymer (1.0 g, 2.5 g or 5.0 g), polymerization time (30 min, 120 min and 240 min), ultrasonic bath temperature (40 °C and 70 °C), and type of bath to obtain the sol-gel (ultrasonic bath, water bath with stirring and mechanical stirrer). To complete the FPSE optimization, the influence of pesticide extraction time on FPSE and desorption from FPSE in ethyl acetate was also assessed.The pesticides extraction yields obtained for the laboratory textile samples are in the range of 52.7 %–128.0 %. The technique proposed in the manuscript proved to be effective as a nondestructive tool for evaluating and quantifying the presence of pesticides in textile museum collections. The approach described here reduces heritage object damage due to sampling compared to methods commonly employed and may represent a starting point for future research.

Dispersive liquid–liquid microextraction based on deep eutectic solvent followed by high-performance liquid chromatography-ultraviolet for imidacloprid, hexythiazox, and fenpyroximate determination: Experimental design approach

Dispersive liquid–liquid microextraction (DLLME) of three insecticides, including imidacloprid (I), hexythiazox (H), and fenpyroximate (F), was performed as an efficient method for separation and preconcentration using a deep eutectic choline chloride-acetic acid solvent (DES) followed by determination by high-performance liquid chromatography-ultraviolet (HPLC-UV). The experimental design approach (central composite design) was used to optimize the effective parameters. According to the results, the addition of salt had no significant effect on extraction among the four parameters studied, including pH, DES volume (dispersive solvent), salt concentration, and chloroform volume. The optimized conditions in the DES-DLLME-HPLC-UV method were pH = 6.00, 100 µL DES, and 138 µL chloroform. Under optimized conditions, a wide linear range of 1.00 × 10−3-20.00 µg mL−1 was obtained for three insecticides. The enhancement factors were 11.22, 58.04, and 39.65 and the limit of detection of 3.00 × 10−4, 2.00 × 10−4, and 2.00 × 10−4 µg mL−1, and the limit of quantification of 9.00 × 10−4, 8.00 × 10−4, and 6.00 × 10−4 µg mL−1 were also determined for imidacloprid, hexythiazox, and fenpyroximate, respectively. The presence of other components including benomyl, dimethoate, mancozeb, captan, thiodicarb, carbendazim, and oxyfluorfen, showed no significant interference effect on the determination of three insecticides up to 50-fold. The method is eco-friendly benign, sensitive, precise, and straightforward as shown by the results.

Combination of distance-based paper analytical devices with ionic liquid-based dispersive liquid-liquid microextraction for enzyme-free bilirubin quantification

This article introduces the first demonstration of integrating distance-based paper analytical devices (dPADs) with ionic liquid-based dispersive liquid-liquid microextraction (IL-DLLME) for the quantitative detection of bilirubin levels in human samples. In this approach, bilirubin is preconcentrated and extracted into a small droplet of the extraction solvent using IL-DLLME. The resulting solution is then introduced into an economical and straightforward dPAD sensor. Detection relies on a colorimetric reaction between bilirubin and gold ions (Au3+), leading to the in-situ formation of gold nanoparticles (AuNPs) on the paper substrate. The observed red-purple distance length is directly proportional to the bilirubin level. Under optimization, a linear range between 0.25 nM and 5.0 nM (R2 = 0.9979) and a detection limit (LOD) of 250.0 pM were achieved. The assay exhibits notable precision and selectivity without any interference. With its distance readout feature, this method is simpler and more cost-effective, offering greater sensitivity compared to other methods requiring expensive reagents and instruments. Moreover, the technique shows high accuracy and precision for bilirubin quantification in human control samples, with recoveries ranging from 98.33% to 102.00%. No significant difference was observed between our method and the enzyme-linked immunoassay (ELISA) method. By combining a low-cost microfluidic device with a simple microextraction method, this strategy holds great potential as an alternative analytical method for determining bilirubin. It can be expanded for further applications in analytical sensing for point-of-care (POC) diagnostics.

The determination of mycotoxins using isotope-coded labeling and dispersive liquid–liquid microextraction by high throughput flow injection analysis coupled with tandem mass spectrometry

A novel and rapid method for the determination of ochratoxin A (OTA), funmonisin B1 (FB1) and zearalenone (ZEN) in legumes samples by high throughput flow injection analysis-tandem mass spectrometry (FIA-MS/MS) in conjunction with isotope-coded labeling (ICD) coupled with dispersive liquid–liquid microextraction (DLLME) was developed. The samples were extracted by a known QuEChERS method (Quick, Easy, Cheap, Effective, Rugged, Safe). The extracted components and mycotoxin standards were, respectively, labeled by d0-10-methyl-acridone-2-sulfonyl chloride and its deuterated counter part (d3-MASC). Subsequently, the mixed light-/heavy-labeled solutions were enriched and purified by DLLME method and corresponding extracts were directly used for FIA-MS/MS analysis. The FIA-MS/MS method coupled with ICD-coded labeling technique for the determination of mycotoxins in legume samples could be achieved within 2 min, which was much suitable for high throughput screening analysis. Meanwhile, the labeled mycotoxins with d3-MASC as internal standards could effectively eliminate matrix interference and ensure the accuracy and precision of mass spectrometry analysis. The limits of detection (LODs) and the limits of quantification (LOQs) ranged from 0.29 to 0.42 μg/L and 0.85 to 1.30 μg/L, respectively. The recoveries were 66.9 %–85.2 %, and the daily and inter day RSDs were within the range of 2.0 %–4.9 % and 2.4 %–5.0 %, respectively. The established method could be feasibility applied to the determination of mycotoxins in legume samples with satisfactory results.

In situ formation of solidified supramolecular solvent based dispersive liquid-liquid microextraction for the enrichment of phenylurea herbicides in water, fruit juice, and milk

A convenient, efficient, and green dispersive liquid-liquid microextraction based on the in situ formation of solidified supramolecular solvents combined with high performance liquid chromatography was developed for the determination of four phenylurea herbicides in liquid samples, including monuron, monolinuron, isoproturon, and chlortoluron. Herein, a novel supramolecular solvent was prepared by the in situ reaction of [P4448]Br and NH4PF6, which had the advantages of low melting point, high density, and good dispersibility. In addition, the microscopic morphology and physical properties of supramolecular solvent were characterized, and the extraction conditions were optimized. The results showed that the analytes had good linearity (R2 > 0.9998) within the linear range. The limits of detection and quantification for the four phenylurea herbicides were in the range of 0.13–0.19 μg L−1 and 0.45–0.65 μg L−1, respectively. The prepared supramolecular solvent is suitable for the efficient extraction of phenylurea herbicides in water, fruit juice, and milk.

Sensitive quantification of acetochlor and metolachlor in water using Taguchi-optimized DLLME coupled with high-performance liquid chromatography

In this study, we developed a method that is sensitive, simple, and environmentally friendly for quantifying acetochlor and metolachlor. This method combines vortex-assisted dispersive liquid–liquid microextraction (DLLME) with high-performance liquid chromatography (HPLC). HPLC operating parameters and extraction parameters for direct and post-extraction analyses of acetochlor and metolachlor were optimized by employing the Taguchi experimental design method. The optimized HPLC parameters for acetochlor and metolachlor were 1.00 mL/min and 1.2 mL/min flow rate, 40 °C column temperature, and 70/30 (ACN/Water) and 80/20 (ACN/Water) at 210 and 230 nm wavelengths, respectively, for the direct injection method. For the DLLME procedure, 1,2-dichloroethane extraction solvent type, acetonitrile, and methanol dispersive solvent type, 400 µL and 300 µL extraction solvent volumes, and 1.0 mL dispersive solvent volume were the optimized DLLME extraction parameters, respectively. The developed and optimized methods for acetochlor and metolachlor analyses exhibited satisfactory validation results, with excellent linearity, indicated by R2 values greater than 0.99. The limit of detection (LOD) and the limit quantification (LOQ) levels of acetochlor and metolachlor were 28.96 to 31.25 µg/L, and 86.87 to 93.75 µg/L for direct injection, and 1.15 to 1.24 µg/L and 3.47 to 3.75 µg/L for post-extraction, respectively. The DLLME recovery values were within the range of 82.6–99.2 % (relative standard deviations-RSD: 4.47–10.13 %) for acetochlor and 91.1–103.4 % (4.31–7.96 %) for metolachlor. Repeatability and reproducibility results (n = 10) of direct injection and post-extraction methods for fortified acetochlor and metolachlor samples displayed very high precision lower than 2 % RSD.

A Univariate Optimization Strategy for Pre-concentration of Cobalt(II) in Various Matrixes by a DLLME before Analysis Using FAAS

A procedure based on dispersive liquid-liquid microextraction (DLLME) for cobalt (Co) quantification in an Iraqi environmental matrix by flame atomic absorption spectroscopy (FAAS) was applied in this work. A case-study approach was chosen to obtain further in-depth information on the Co levels and to evaluate the effectiveness of N-salicylideneaniline (SAN) as a complexing agent for pre-concentration and extraction of Co. An univariate strategy was utilized to achieve the optimum extraction conditions. The estimated limits of detection (LOD) and quantification (LOQ) under optimum conditions were 1.04 and 3.47 µg L−1, respectively. The results achieved by the proposed system were compared with those using the microwave digestion/graphite furnace atomic absorption spectrometer (MWD/GF-AAS) for digest samples and also for some water samples (Direct GF-AAS). The proposed procedure was applied for analyzing eleven environmental samples. The detectable Co levels for water samples ranged from 0.72 to 4.30 µg L−1 with a relative standard deviation of 3.7–8.8%, while the concentration for solid samples ranged from 0.17–4.51 µg g−1 (2.4–11.8 RSD %). DLLME/FAAS proposed procedure is effective, simple, and has the benefit of minimizing the organic solvent consumption by a few microliters, which results in little waste.

Development of a dispersive liquid-liquid microextraction method for the evaluation of maternal-fetal exposure to cocaine employing human umbilical cord tissue.

Illicit drug use is a serious and complex public health problem, not only due to the severity of the health damage but also to the social implications, such as marginalization and drug trafficking. Currently, cocaine (COC) is among the most abused drugs worldwide with about 22 million users. Drug abuse has also been found in women during the pregnancy period, which has shed light on a new group for epidemiology. The diagnosis of COC use in these cases usually depends largely on the mother's reports, which in several cases omit or deny consumption. Therefore, considering physical-chemical methods of sample preparation and exposure biomarkers, the development of analytic toxicological methods can help to confirm drug use during pregnancy. Thus, the objective of the present work was to develop an analytical method based on dispersive liquid-liquid microextraction (DLLME) for the determination of COC analytes, using umbilical cord tissue as an alternative biological matrix, and detection by gas chromatography coupled to mass spectrometry (GC-MS). Therefore, after optimization, the DLLME method was fully validated for quantification of COC, benzoylecgonine (BZE), cocaethylene (CE), ecgonine (ECG), ecgonine methyl ester (EME) and norcocaine (NorCOC). The limits of detection were between 15 and 25 ng/g, the limits of quantification (LOQ) were 30 ng/g for ECG, and 25 ng/g for the other analytes. Linearity ranged from the LOQ to 1,000 ng/g. Coefficients of variation for intra-assay precision were <18.5%, inter-assay was <8.75%, and bias was <16.4% for all controls. The developed method was applied in 10 suspected positive samples, based on the mother's report and maternal urine screening and confirmation. COC, BZE, ECG, and EME were quantified in 4 umbilical cords with concentrations that ranged from 39.6 to 420.5 ng/g.

Detection of trace components in Xiangdan injection of Dalbergia odorifera based on microextraction and back-extraction along with bar-form-diagram strategy

Xiangdan Injection are commonly used traditional Chinese medicine formulations for the clinical treatment of cardiovascular diseases. However, the trace components of Dalbergia odorifera in Xiangdan Injection pose a challenge for evaluating its quality due to the difficulty of detection. This study proposes a technology combining dispersive liquid-liquid microextraction and back-extraction (DLLME-BE) along with Bar-Form-Diagram (BFD) to address this issue. The proposed combination method involves vortex-mixing tetradecane, which has a lower density than water, with the sample solution to facilitate the transfer of the target components. Subsequently, a new vortex-assisted liquid-liquid extraction step is performed to enrich the components of Dalbergia odorifera in acetonitrile. The sample analysis was performed on HPLC-DAD, and a clear overview of the chemical composition was obtained by integrating spectral and chromatographic information using BFD. The combination of BFD and CRITIC-TOPSIS strategies was used to optimize the process parameters of DLLME-BE. The determined optimal sample pre-treatment process parameters were as follows: 200 μL extraction solvent, 60 s extraction time, 50 μL back-extraction solvent, and 90 s back-extraction time. Based on the above strategy, a total of 29 trace components, including trans-nerolidol, were detected in the Xiangdan Injection. This combination technology provides valuable guidance for the enrichment analysis of trace components in traditional Chinese medicines.

Determination of Fe, Cu, and Pb in edible oils using choline chloride:ethylene glycol deep eutectic solvent-based dispersive liquid-liquid microextraction associated with microwave-induced plasma optical emission spectrometry

A new simple, fast and environmentally friendly deep eutectic solvent based dispersive liquid-liquid microextraction (DES-based DLLME) methodology assisted by vortex is presented for the separation and preconcentration of three elements (i.e., Fe, Cu and Pb) from edible oil samples (i.e., soybean, sunflower, rapeseed, sesame, and olive oil) prior to the determination by microwave-induced plasma optical emission spectrometry (MIP-OES). The deep eutectic solvent selected as extractant (i.e., choline chloride and ethylene glycol, 1:2) is synthesized and characterized by Fourier transform infrared spectroscopy (FT-IR), proton nuclear magnetic resonance spectroscopy (1H NMR) and differential scanning calorimetry (DSC), and the extraction conditions are optimized by a two steps experimental design. Under the optimum extraction conditions (i.e., diluted sample weight: 8.6 g; DES volume: 100 μL; extraction time: 1 min; centrifugation time and speed: 3 min and 3000 rpm; and dispersion system: vortex) the analytical method presents excellent linearity (i.e., R2 values higher than 0.99) in the range 10–500 μg kg−1, repeatability (i.e., CV values lower than 9.2%), and limits of detection (LOD) values of 3, 2 and 0.7 μg kg−1 for Pb, Fe and Cu, respectively. None of the analytes displayed amounts over the upper limit permitted by law, and recovery values of all analytes evaluated in the different samples using external standard calibration were close to 100%, which excludes significant matrix effects. Finally, AGREEprep metric has been used to evaluate the method greenness (final score of 0.47) and it has been compared successfully with previous publications for the same type of analytes and matrices.

Determination of aflatoxins in rice from Penang, Malaysia by dispersive liquid–liquid micro-extraction and LC–MS/MS

Rice is one of the crops cultivated in Malaysia, and it is the main diet for most of the population. In this study, dispersive liquid–liquid micro-extraction (DLLME) and liquid chromatography–tandem mass spectrometry (LC–MS/MS) were used to develop, optimise and validate a reliable, easy-to-use and quick approach to detect aflatoxin B1 (AFB1), aflatoxin B2 (AFB2), aflatoxin G1 (AFG1) and aflatoxin G2 (AFG2). The extraction recoveries in DLLME were enhanced by the addition of 5% salt, utilising chloroform as the extraction solvent and acetonitrile as the dispersive solvent. The DLLME parameters – the extraction solvent volume, salt concentration and dispersive solvent volume were optimised with Box–Behnken design (BBD) and response surface methodology (RSM). Under optimised experimental conditions, excellent linearity was obtained with a limit of detection (LOD) ranging from 0.125 to 0.25 ng g−1, a limit of quantitation (LOQ) ranging from 0.25 to 0.3 ng g−1 and a correlation value (R 2) of 0.990. The matrix effects were between −11.1% and 19.9%, and recoveries ranged from 87.4% to 117.3%. The optimised and validated method was used effectively to assess aflatoxins contamination in 20 commercial rice samples collected from local supermarkets in Penang, Malaysia. AFB1 was detected at 0.41–0.43 ng g−1 in two rice samples, below the regulatory limit.

Simultaneous extraction of polycyclic aromatic hydrocarbons and tetracycline antibiotics from honey samples using dispersive solid phase extraction combined with dispersive liquid-liquid microextraction before their determination with HPLC-DAD

A dispersive solid-phase extraction method combined with dispersive liquid-liquid microextraction was offered for the extraction of four polycyclic aromatic hydrocarbons (anthracene, fluorene, phenanthrene, and pyrene) and tetracycline antibiotics (tetracycline, oxytetracycline, and chlortetracycline) from honey samples, simultaneously. In this work, cobalt-gallic acid bio-metal organic framework was synthesized and 20 mg of it was added into of 10 mL the diluted honey solution to efficiently adsorb the analytes. After vortexing (3 min) and centrifuging, the sorbent particles were eluted with 0.75 mL acetonitrile under vortexing for 3 min. In the following, this phase was mixed with 55 µL [Ch: 4-chlorophenol]+[FeCl4]- magnetic deep eutectic solvent and rapidly injected into deionized water. After separating the extractant phase in the presence of an external magnet and diluting it with the mobile phase, it was injected into a high-performance liquid chromatography-diode array detector. Under optimum extraction conditions, extraction recoveries were in the range of 63–84%. The limits of detection of the opted polycyclic aromatic hydrocarbons and tetracyclines were in the ranges of 0.18–0.26 and 0.25–0.29 ng g−1, respectively. Also, good repeatability (relative standard deviations ≤ 7.5 and 8.3% for intra– (n=6) and inter-day (n=4) precisions, respectively) was obtained. In summary, the validated method was successfully recommended for the determination of polycyclic aromatic hydrocarbons and tetracyclines in various honey samples and pyrene was found in two samples at 5.5 and 12.9 ng g−1. The used bio-metal organic framework has sufficient ability in extraction of different classes of compounds (polycyclic aromatic hydrocarbons and antibiotics) from honey. Performing the microextraction step has direct effect in analysis of the analytes in low concentrations and the use of magnetic solvents, eliminate the use of centrifugation in this step.

Investigation of different solvents for selective, safe and rapid extraction of curcumin from various food and herbal supplement products: Multivariate strategy and assessment of green profile

In the paper, different extraction solvents including magnetic ionic liquids (MILs), deep eutectic solvents, SUPRAS and surfactant were investigated for the fast, reliable and simple extraction of curcumin in the dispersive liquid–liquid microextraction (DLLME) method prior to UV–Vis spectrophotometric analysis. As a result of preliminary studies, the [Co(C8IM)42+]2[Cl−] MIL was selected as the extraction solvent for the extraction of curcumin from various matrix samples. Optimization of essential factors in the DLLME method was carried out with central composite design (CCD). Effective dispersion of the [Co(C8IM)42+]2[Cl−] MIL in the sample solution was achieved by orbital shaking (OS). After the CCD modelling, the OS-MIL-DLLME method provided linearity in the range of 0.5–225 ng mL−1 with a detection limit of 0.15 ng mL−1 for the model solution. The OS-MIL-DLLME method showed a matrix effect of 7.6 % with an enrichment factor of 135. Validation parameters of the OS-MIL-DLLME method such as selectivity, robustness, intraday/interday precision and recovery test were investigated in detail. The green analytical scale of the method was determined using the analytical greenness calculator tool. The OS-MIL-DLLME method was applied to the foods and herbal supplement products together with the reference method, and quantitative recoveries and statistically reliable results were obtained.

Terpenes based hydrophobic deep eutectic solvents for dispersive liquid-liquid microextraction of aliphatic aldehydes in drinking water and alcoholic beverages

Aliphatic aldehydes are a class of organic compounds containing aldehyde groups, which are widespread, and closely related to people's daily life and health. In this work, a series of terpenes based hydrophobic deep eutectic solvents were designed and synthesized using hexafluoroisopropanol as hydrogen bond donor and menthol/thymol as hydrogen bond acceptor. Then they are used as extraction solvent in dispersive liquid-liquid microextraction for extracting and determining seven aliphatic aldehydes from drinking water and alcoholic beverage combined with high performance liquid chromatography-ultraviolet. Due to the fact that these hydrophobic deep eutectic solvents are liquid at the room temperature, a density greater than that of water, a lower viscosity (≤26.10 mPa s, 25 °C), after extraction and centrifugation, the microvolume DES-rich phase in the bottom is convenient for collection and direct analysis without further dissolution or dilution with organic solvents. Some factors affecting the extraction recovery were optimized by one-variable-at-a-time and response surface methodology. Under the optimal conditions, the enrichment factors for the seven aliphatic aldehydes were 48–56. The method had good performance: linear ranges of 1.0–200, 0.5–200, 0.2–200, 0.4–400, 1.0–400, 0.4–400 and 0.4–400 μg L−1 for seven aliphatic aldehydes (r2 ≥ 0.9949), limits of detection of 0.1–0.5 μg L−1, intra-day and inter-day precisions <4.9%. The recoveries of seven aliphatic aldehydes ranged from 76.0 to 119.0%. The proposed dispersive liquid-liquid microextraction method is simple, rapid, highly efficient, and green, which effectively reduces the amount of toxic chemical reagents used and their impact on the environment. Rapid and efficient detection of aliphatic aldehydes helps ensure a healthy diet and has great application prospects in food safety analysis.

Deep eutectic solvent-based pressurized liquid extraction combined with dispersive liquid-liquid microextraction of organophosphorus pesticide residues in egg powder prior to high-performance liquid chromatography analysis.

Herein, a deep eutectic solvent (DES)-based miniaturized pressurized liquid extraction in combination with DES-based dispersive liquid-liquid microextraction (DLLME) was developed for the extraction of organophosphorus pesticides (parathion-methyl, triazophos, parathion, diazinon, and phoxim) from egg powder samples prior to their analysis by a high-performance liquid chromatography-diode array detector. In this work, first, the analytes' extraction was done by a pressurized liquid phase extraction for effective extraction of the analytes from the solid matrix, and then they were concentrated on a DLLME for more concentration of the analytes to reach low limits of detections. The use of DESs was done in both steps to omit the use of toxic organic solvents. Satisfactory results including high extraction recoveries (74-90%), great repeatability (relative standard deviations equal or less than 4.3% and 5.3% for intra- and inter-day precisions), and low limits of detection (0.11-0.29ng/g) and quantification (0.38-0.98ng/g) were attained under the optimum conditions. Lastly, the suggested approach was utilized for the determination of the studied pesticides in various egg powder samples marketed in Tabriz, Iran.