Liquid-liquid Microextraction Research Articles

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.

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

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.

Supramolecular deep eutectic solvent: a powerful tool for pre-concentration of trace metals in edible oil.

The utilization of supramolecular deep eutectic solvent eddy-assisted liquid-liquid microextraction utilizing 2-hydroxypropyl β-cyclodextrin (SUPRADES) has been identified as a successful method for pre-enriching Cu, Zn, and Mn in vegetable oil samples. Determination of each element was conducted by inductively coupled plasma optical emission spectrometry (ICP-OES) after digestion of metal-enriched phases. Various parameters were examined, including the composition of SUPRADES species [2HP-β-CD: DL-lactic acid], a cyclodextrin mass ratio of 20wt%, a water bath temperature of 75 °C, an extractor volume of 800 μL, a dispersant volume of 50μL, and an eddy current time of 5min. Optimal conditions resulted in extraction rates of 99.6% for Cu, 105.2% for Zn, and 101.5% for Mn. The method exhibits a broad linear range spanning from 10 to 20,000μg L-1, with determination coefficients exceeding 0.99 for all analytes. Enrichment coefficients of 24, 21, and 35 were observed. Limits of detection ranged from 0.89 to 1.30μg L-1, while limits of quantification ranged from 3.23 to 4.29 μg L-1. The unique structural characteristics of the method enablethe successful determination of trace elements in a variety of edible vegetable oils.

Amine Switchable Hydrophilic Solvent Vortex-Assisted Homogeneous Liquid-Liquid Microextraction and GC-MS for the Enrichment and Determination of 2, 6-DIPA Additive in Biodegradable Film.

2, 6-diisopropylaniline (2, 6-DIPA) is a crucial non-intentionally organic additive that allows the assessment of the production processes, formulation qualities, and performance variations in biodegradable mulching film. Moreover, its release into the environment may have certain effects on human health. Hence, this study developed simultaneous heating hydrolysis-extraction and amine switchable hydrophilic solvent vortex-assisted homogeneous liquid-liquid microextraction for the gas chromatography-mass spectrometry analysis of the 2, 6-DIPA additive and its corresponding isocyanates in poly(butylene adipate-co-terephthalate) (PBAT) biodegradable agricultural mulching films. The heating hydrolysis-extraction conditions and factors influencing the efficiency of homogeneous liquid-liquid microextraction, such as the type and volume of amine, homogeneous-phase and phase separation transition pH, and extraction time were investigated and optimized. The optimum heating hydrolysis-extraction conditions were found to be a H2SO4 concentration of 2.5 M, heating temperature of 87.8 °C, and hydrolysis-extraction time of 3.0 h. As a switchable hydrophilic solvent, dipropylamine does not require a dispersant. Vortex assistance is helpful to speed up the extraction. Under the optimum experimental conditions, this method exhibits a better linearity (0.0144~7.200 μg mL-1 with R = 0.9986), low limit of detection and quantification (0.0033 μg g-1 and 0.0103 μg g-1), high extraction recovery (92.5~105.4%), desirable intra- and inter-day precision (relative standard deviation less than 4.1% and 4.7%), and high enrichment factor (90.9). Finally, this method was successfully applied to detect the content of the additive 2, 6-DIPA in PBAT biodegradable agricultural mulching films, thus facilitating production process monitoring or safety assessments.

Developing of an eco-friendly liquid-liquid microextraction method by using menthol-based hydrophobic deep eutectic solvent for determination of basic fuchsin dye: assessment of the greenness profile.

Herein, we aimed to develop a new environmentally friendly liquid-liquid microextraction (LLME) method based on hydrophobic deep eutectic solvent (hDES) synthesized using biodegradable dl-menthol and decanoic acid for the spectrophotometric determination of toxic basic fuchsin dye in environmental water samples. The parameters affecting the extraction efficiency such as pH, mole ratio, and volume of hDES (1:2) and type and volume of organic solvent, sample volume, times of vortex, ultrasonic bath and centrifuge, ionic strength, and matrix effect were investigated and optimized. Under optimal conditions, the calibration curve showed linearity in the range of 7.4-167μg L-1 with a coefficient of determination of 0.9994. The limit of detection, intra-day and inter-day precision, and recovery values were 2.25μg L-1, 2.46% and 4.45%, and 105 ± 3%, respectively. The preconcentration and enrichment factors were found to be 30 and 61.5, respectively. The proposed hDES-LLME methodology was successfully applied to the environmental water samples to detect toxic BF dye (95-105%). Finally, the ecological impact of the suggested method was evaluated using the analytical eco-scale (PPS:88), complementary green analytical procedure indexe (ComplexGAPI), and the Analytical GREEnness tool (0.63). The assessment results showed that the presented analytical method can be regarded as a green LLME approach for the determination of the BF in water.

Development of CO2-switchable deep eutectic solvent-based liquid-liquid microextraction approach: Application in urinary excretion and tissue distribution studies

BackgroundPharmacokinetic studies are pivotal in drug development, focusing on absorption, distribution, and excretion of active compounds. Effective sample preparation methods play a crucial role in these studies. Traditional techniques like protein precipitation and liquid-liquid extraction often involve toxic solvents and are time-consuming. Recently, deep eutectic solvent (DES) has emerged as an eco-friendly alternative due to its high efficiency, low cost, and low toxicity. This study introduces a novel sample pretreatment method using CO2-switchable DES in liquid-liquid microextraction (LLME) to enhance speed, accuracy, and sensitivity in complex biological samples analysis. ResultsA liquid-liquid microextraction sample pretreatment method based on switchable DES combined with high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was established for the analysis of urine and tissue samples. The method was optimized through systematic investigation of key parameters, including DES type, volume, molar ratio, pH, vortex time, gas purge time, and salt addition. The resulting procedure exhibited satisfying linearity (r2 ≥ 0.9958), good precision (RSD ≤6.01 %), desirable recovery (52.44%–98.12 %) and matrix effect (86.22%–119.30 %), and the accuracy and precision of stability were within the ±15 % limit. The proven methods were further applied to urinary excretion study and tissue distribution study of Nelumbinis plumula (NP) extract. The results indicated that the total cumulative excretion of liensinine, isoliensinine and neferine in urine within 240 h was 4.96 %, 0.66 % and 0.44 %, respectively. The tissue distribution study showed that alkaloids mainly distribute in liver, kidney, and spleen. SignificanceThis research introduces a groundbreaking technique distinguished by its simplicity, speed, cost-effectiveness, and environmental friendliness. This approach, utilizing CO2-switchable DES as an extraction solvent for LLME, integrates deproteinization and removal of interfering molecules into a single step. This integration showcases its efficiency and convenience, demonstrating significant promise for various applications in the analysis of biological samples. Additionally, this study provides the first report on urinary excretion and tissue distribution of alkaloids from NP using a DES-LLME method. These findings offer valuable insights into the in vivo behavior of herbal medicine, enhancing understanding of pharmacological actions and facilitating clinical rational administration.

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.

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.

In situ formation of a deep eutectic solvent for liquid-liquid microextraction of synthetic phenolic antioxidants in edible oil

A simple and ecofriendly liquid-liquid microextraction (LLME) method was developed for the extraction of synthetic phenolic antioxidants (SPAs, e.g. tert-butyl hydroquinone (TBHQ) and butylated hydroxyanisole (BHA)) in edible oil. Compared with time-consuming and cumbersome off-line prepared deep eutectic solvent (DES), the in-situ formulated DES allowed to directly add DES components into sample matrix, making the sample preparation procedure greatly simplified. Preliminary experiment indicated that the DES made of 1:2 (molar ratio) tetrabutylammonium chloride (TBAC) and acetic acid (AA) was suitable for the extraction of SPAs. Under the optimized conditions, by combining with HPLC, the in-situ DES-LLME-HPLC method showed satisfactory detection limits (0.7−1.3 μg/L), precisions (RSDs≤5.0%), enrichment factors (20.8−22.0), recoveries (89.2%–103.6%), and linearity over 5−500 μg/L (TBHQ) and 10−500 μg/L (BHA) (R2 ≥ 0.9991). In addition, the method displayed acceptable matrix effect and robustness. Hence, it is promising for the extraction and determination of SPAs in real edible oil.

High-throughput semi-automated emulsive liquid-liquid microextraction for detecting SDHI fungicides in water, juice, and alcoholic beverage samples via UHPLC-MS/MS

Herein, a High-Throughput Semi-automated Emulsive Liquid-Liquid Microextraction (HTSA-ELLME) method was developed to detect Succinate Dehydrogenase Inhibitor (SDHI) fungicides in food samples via UHPLC-MS/MS. The Oil-in-Water (O/W) emulsion comprising a hydrophobic extractant and water was dilutable with the aqueous sample solution. Upon injecting the primary emulsion into the sample solution, a secondary O/W emulsion was formed, allowing SDHI fungicides to be extracted. Subsequently, a NaCl-saturated solution was injected in the secondary O/W emulsion as a demulsifier to rapidly separate the extractant, eliminating the need for centrifugation. A 12-channel electronic micropipette was used to achieve a high-throughput semi-automation of the novel sample pretreatment. The linear range was 0.003–0.3 μg L−1 with R2 > 0.998. The limit of detection was 0.001 μg L−1. The HTSA-ELLME method successfully detected SDHI fungicides in water, juice, and alcoholic beverage samples, with recoveries and relative standard deviations of 82.6–106.9% and 0.8–5.8%, respectively. Unlike previously reported liquid-liquid microextraction approaches, the HTSA-ELLME method is the first to be both high-throughput and semi-automated and may aid in designing pesticide pretreatment processes in food samples.

Aqueous two-phase system based on hexafluoroisopropanol and acetonitrile for homogeneous liquid-liquid microextraction of cationic dyes


 
 
 
 This work demonstrates that an aqueous two-phase system (ATPS) is formed when a small amount of acetonitrile (ACN) is added to the aqueous hexafluoroisopropanol (HFIP) solution. The effect of ACN amount on the volume of the formed HFIP/ACN phase was investigated. It was also shown that relatively hydrophilic methylene blue was completely extracted into the HFIP/ACN phase whereas its extractability with conventional solvents (hexane, CH2Cl2 and CHCl3) was significantly lower. The obtained results suggest that the HFIP/ACN phase exhibits a relatively high polarity and should be a good choice for the extraction of moderately or even highly polar compounds from aqueous samples. Finally, the developed ATPS was applied for the homogeneous liquidliquid microextraction of four cationic dyes from river water samples prior to HPLC analysis. Under optimised extraction conditions, the enrichment factors were around 150. Calibration curves were linear (R2 ≥ 0.9959) for the concentration level between 0.2–0.5 and 50.0 μg/L and the detection limits were in the range 0.05–0.18 μg/L. The recoveries of the dyes for the spiked water samples were 88.6–98.5%, with the relative standard deviation values less than 9.6%.
 
 
 

Switchable hydrophilicity solvent-based hollow fibre liquid-liquid microextraction – headspace gas chromatography for determination of benzene and its derivatives in water samples


 
 
 
 A novel, cost-effective, simple and environmentally friendly method was developed for separating, preconcentrating and quantifying volatile analytes. That approach utilised switchable hydrophilicity solvent-based hollow fiber liquid-liquid microextraction in combination with headspace gas chromatography. The extraction was carried out from 1 l of water solution. 100 μl of nonanoic acid, immobilised within a polypropylene capillary, was selected as an extraction solvent. After the extraction, the capillary with the extract was transferred to a headspace vial, and headspace gas chromatographic analysis was performed. To facilitate the transition of volatile analytes to the headspace for subsequent analysis, nonanoic acid was converted to hydrophilic nonanoate by adding a sodium hydroxide solution.
 The effectiveness of the suggested strategy was demonstrated in the determination of benzene and its derivatives in water samples. Various parameters affecting the extraction and headspace gas chromatographic determination were investigated and optimised. Under the optimal conditions, the analytical characteristics of the proposed technique were determined.
 Using this approach, the limits of quantification for all analytes were found to be below the maximum acceptable concentration.
 
 
 

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.

Development of UV‐Vis spectroscopy-based analysis method for determination of tin(IV) in epilobium parviflorum (hoary willowherb) tea using deep eutectic solvent based preconcentration

In this study, a UV–Vis Spectroscopy-based method was developed for the determination of tin(IV) in epilobium parviflorum tea samples after preconcentration. The preconcentration process was carried out using the liquid-liquid microextraction technique. Before starting the analysis, optimization studies were carried out for the variables likely to affect the experimental results. As a result of the analyzes performed under optimum conditions, the detection limit of our method was calculated as 16.83 μg/L. The percent relative standard deviation value was calculated as 1.25% (n = 8) and linearity was found in the range of 10–1000 μg/L. Recovery experiments were performed on epilobium parviflorum tea samples using the matrix matching method. As a result of the analyzes made on teas belonging to three different brands, recovery results ranging from 92 to 117% were obtained.

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.