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

INTRODUCTION

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.

OBJECTIVE

The aim of this work is to compare three miniaturised extraction techniques for extracting the main ayahuasca compounds from beverages.

METHODOLOGY

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).

RESULTS

The procedure was optimised, with the final conditions being 500 μL of extractor solvent, 85 mg of primary secondary amine (PSA) and 4 s of vortexing. The analytical method was validated, showing to be linear between 0.16 and 10 μg/mL for β-carbolines and between 0.016 and 1 μg/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%.

CONCLUSION

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.

Dispersive liquid-liquid microextraction (DLLME) for determination of tricyclic antidepressants in whole blood and plasma samples and analysis by liquid chromatography with diode array detector (LC-DAD)

Microextractions have been developed for the tricyclic antidepressants (TCAs) analysis in biological matrices, including dispersive liquid-liquid microextraction (DLLME). The proposed DLLME employed 490 µL of biological sample (whole blood or plasma), which were added 15 mg of NaCl, 10 µL of medazepam as internal standard (10 µg/mL) and 100 µL of 2 M NaOH. This mixture was homogenized by vortex (2800 rpm/10 s) and 400 µL of hexane (extractor solvent) with 600 µL of methanol (dispersing solvent) were added to the sample. After the vortex step (2800 rpm/5 s), an ultrasonic bath for 300 s was employed. Then, this content was centrifuged (10 min/10000 rpm), organic phase was collected and dried under air flow. After, 30 µL of the mobile phase was used for resuspension and 20 µL is injected into LC-DAD. This method was optimized and fully validated according to UNODC and SWGTOX guidelines, reaching limits of detection equivalent to analytical methodologies that employ mass spectrometry (MS). Also, it was applied in real cases involving suspected exposure to TCAs. So, the developed DLLME for the determination of TCAs in whole blood and plasma samples proved to be a simple, reliable, robust and reproducible method that can be used in toxicology and clinical laboratories.

Recent Advances in Dispersive Liquid-Liquid Microextraction for Pharmaceutical Analysis

Sample clean-up and pre-concentration are critical components of pharmaceutical analysis. The dispersive liquid-liquid microextraction (DLLME) technique is widely recognized as the most effective approach for enhancing overall detection sensitivity. While various DLLME modes have been advanced in pharmaceutical analysis, there need to be more discussions on pre-concentration techniques specifically developed for this field. This review presents a comprehensive overview of the different DLLME modes used in pharmaceutical analysis from 2017 to May 2023. The review covers the principles of DLLME, the factors affecting microextraction, the selected applications of different DLLME modes, and their advantages and disadvantages. Additionally, it focuses on multi-extraction strategies employed for pharmaceutical analysis.

Evaluation of distribution of emerging mycotoxins in human tissues: applications of dispersive liquid-liquid microextraction and liquid chromatography-mass spectrometry

In this work, a complete study of the distribution of emerging mycotoxins in the human body has been carried out. Specifically, the presence of enniatins (A, A1, B, B1) and beauvericin has been monitored in brain, lung, kidney, fat, liver, and heart samples. A unique methodology based on solid-liquid extraction (SLE) followed by dispersive liquid-liquid microextraction (DLLME) was proposed for the six different matrices. Mycotoxin isolation was performed by adding ultrapure water, acetonitrile, and sodium chloride to the tissue sample for SLE, while the DLLME step was performed using chloroform as extraction solvent. Subsequently, the analysis was carried out by high-performance liquid chromatography coupled to tandem mass spectrometry (HPLC-MS/MS). The proposed method allowed limits of quantification (LOQs) to be obtained in a range of 0.001-0.150 ng g-1, depending on the tissue and mycotoxin. The precision was investigated intraday and interday, not exceeding of 9.8% of relative standard deviation. In addition, trueness studies achieved 75 to 115% at a mycotoxin concentration of 25 ng g-1 and from 82 to 118% at 5 ng g-1. The application of this methodology to 26 forensic autopsies demonstrated the bioaccumulation of emerging mycotoxins in the human body since all mycotoxins were detected in tissues. Enniatin B (ENNB) showed a high occurrence, being detected in 100% of liver (7 ± 13 ng g-1) and fat samples (0.2 ± 0.8 ng g-1). The lung had a high incidence of all emerging mycotoxins at low concentrations, while ENNB, ENNB1, and ENNA1 were not quantifiable in heart samples. Co-occurrence of mycotoxins was also investigated, and statistical tests were applied to evaluate the distribution of these mycotoxins in the human body.

A new method for the therapeutic drug monitoring of chlorpromazine in plasma by gas chromatography-mass spectrometry using dispersive liquid-liquid microextraction

Background: Chlorpromazine is the first antipsychotic drug developed and is included in the list of 'essential drugs' prepared by the WHO. Therapeutic drug monitoring is an important point for psychotropic drugs because of significant genetic variability in their metabolism and poor compliance of the patients with treatment. Method: We developed a novel GC-MS method using dispersive liquid-liquid microextraction for the therapeutic monitoring of chlorpromazine. Results: The method was validated according to the European Medicines Agency guidelines. The developed method's lower limit of quantification was set as 30 ng/ml. The calibration curve of chlorpromazine was validated between 30 and 600 ng/ml, with correlation coefficients of more than 0.99. Conclusion: The developed method was applied to real human patient plasma.

Commercial beers: A source of phthalates and di-ethylhexyl adipate

Beer is one of the most consumed beverages worldwide. Different materials used along its production and packaging can result in human exposure to phthalates and adipates. The aim of this study was to assess simultaneously the levels of phthalates and di-ethylhexyl adipate (DEHA) in commercial beer samples (n = 66) with a method based on DLLME and detection with GC-MS/MS, and further evaluate human exposure. Six out of seven compounds studied were found in the beers analysed, with levels ranging from 1.77 to 205.40 µg/L. The most prevalent was DEHA at 205.40 µg/L, while dimethyl phthalate (DMP) was not present in any sample. Samples with 5-6 % alcohol, packed in aluminium cans and produced in an industrial environment presented the highest level of these contaminants. Despite low-risk exposure to phthalates and adipate with beer, it is important to remember the ubiquitous nature of these compounds, which can lead to cumulative exposure.

Dispersant-First Dispersive Liquid-Liquid Microextraction (DF-DLLME), a Novel Sample Preparation Procedure for NDMA Determination in Metformin Products

Since December 2019, global batch recalls of metformin pharmaceutical products have highlighted an urgent need to control N-nitrosodimethylamine (NDMA) contamination to demonstrate patient safety and maintain supply of this essential medicine. Due to their formulation, the metformin extended-release products present difficult analytical challenges for conventional sample preparation procedures, such as artefactual (in-situ) NDMA formation, gelling, and precipitation. To overcome these challenges, a new version of dispersive liquid-liquid microextraction (DLLME) termed dispersant-first DLLME (DF-DLLME) was developed and optimized for the analysis of NDMA in metformin extended-release products using a detailed Design of Experiments (DoE) to optimize sample preparation. Gas chromatography-high resolution accurate mass-mass spectrometry (GC-HRAM-MS) combined with automated DF-DLLME were successfully applied to monitor the NDMA levels of two different metformin extended-release AstraZeneca products to ultra-trace levels (parts per billion). The additional benefits associated with DF-DLLME, which include automation, time/costs saving, and greener sample preparation, make this novel technique easier to transfer from a development to Quality Control (QC) environment. In addition, this also offers an attractive candidate for the wider platform analysis of N-nitrosamines in pharmaceutical drug products.

Optimisation of dispersive liquid-liquid microextraction for plasma sample preparation in bioanalysis of CDK4/6 inhibitors in therapeutic combinations for breast cancer treatment

Cyclin D dependent kinase 4 and 6 (CDK 4/6) inhibitors are novel anticancer drugs used in therapeutic combinations with endocrine therapy for breast cancer treatment. Their determination in patient plasma is of high interest as a prerequisite for possible therapeutic drug monitoring. Dispersive liquid-liquid microextraction (DLLME) shows great potential in bioanalytical sample preparation. Its simplicity and speed, along with the suitability for using small amounts of sample and hazardous solvents are some of its main advantages. However, its application on plasma samples is scarce and requires further development. The aim of this work was to explore the applicability of DLLME in the simultaneous extraction of six drugs of interest from human plasma, with an emphasis placed on achieving high extraction recoveries with low sample and solvent consumption. To tackle the low availability and amount of the plasma sample, as well as the complexity of the biological matrix, three novel DLLME modes are proposed: organic sample DLLME (OrS-DLLME), aqueous sample DLLME (AqS-DLLME), and a modified air-assisted DLLME (AA-DLLME). The extractant and disperser type and volume, volume ratios of all the components in the ternary system, effect of pH and salting out were optimised for all three proposed modes of DLLME. Optimised representative DLLME-HPLC-DAD-FLD method was validated and shown to be linear (R > 0.994), precise (RSD ≤13.8%, interday), accurate (bias -13.1-13.1%, interday) and robust (relative effect -3.34-6.08%). Simultaneous extraction of all six drugs with high recoveries (81.65-95.58%) was achieved. Sample volumes used were as low as 50-100 μL, with necessary organic solvent volumes in μL ranges. Greenness scores obtained using the AGREE software were between 0.63 and 0.66, demonstrating compliance with green analytical chemistry principles. Finally, the validated method was successfully applied on breast cancer patient plasma samples.

Trace nickel determination in seawater matrix using combination of dispersive liquid-liquid microextraction and triethylamine-assisted Mg(OH)2 method

In order to eliminate the effects of seawater matrix on the precise/accurate determination of elements, new and efficient analytical procedure requires. In this study, co-precipitation method based on the triethylamine (TEA)-assisted Mg(OH)₂ was performed to eliminate side-effects of seawater medium on the determination with flame atomic absorption spectrometry (FAAS) prior to the preconcentration of nickel by an optimized dispersive liquid-liquid microextraction (DLLME) method. Under the optimum conditions of the presented method, the limit of detection and quantification (LOD, LOQ) values obtained for nickel were found as 16.1 and 53.8 μg kg^-1, respectively. Seawater samples collected from West Antarctic region were used for real sample applications to check the accuracy and applicability of developed method, and satisfying recovery results (86-97%) were obtained. In addition to this, the digital image-based colorimetric detection system and the UV-Vis system were applied to confirm the applicability of the developed DLLME-FAAS method in other analytical systems.

Combination of extractive techniques followed by HPLC-MS/MS analysis to monitor ent-agathic acid in fish treated with Copaifera duckei Dwyer

Plants are used as therapeutic alternatives in Veterinary Medicine, including therapies for food-producing animals. However, these medicinal resources can sometimes contain dangerous substances, and when used in animals that supply food, they stand out from the point of view of food safety. The diterpene ent-agathic acid, a component of Copaifera duckei oleoresin, is an example of substances already described with toxic activity in mammals. Thus, this study aimed to propose combining two extractive techniques followed by high-performance liquid chromatography coupled mass spectrometry analysis to monitor residues of ent-agathic acid in Piaractus mesopotamicus fillet treated in an immersion bath with Copaifera duckei oleoresin. An optimized combination of solid-liquid extraction (using acidified acetonitrile) and dispersive liquid-liquid microextraction (using acidified water and chloroform as dispersive and extracting solvent, respectively) was performed to recover the target analyte, added to the development of HPLC-MS/MS method with adequate validation parameters to quantify the ent-agathic acid present in the fish fillet. In vivo tests of residual persistence of ent-agathic acid in fishes treated with C. duckei oleoresin were performed, indicating the non-detection of the target diterpene (< 6.1 µg/mL). The combined extractive procedure followed by quantitative analysis in the in vivo test of residual persistence of the target analyte in fish indicated the absence of ent-agathic acid in all samples. Thus, the data found might contribute to understanding the use of oleoresins from C. duckei as an alternative to traditional veterinary products.

Optimization and Validation of Dispersive Liquid-Liquid Microextraction for Simultaneous Determination of Aflatoxins B1, B2, G1, and G2 in Senna Leaves and Pods Using HPLC-FLD with Pre-Column Derivatization

Dispersive liquid-liquid microextraction (DLLME) was optimized for the simultaneous extraction of aflatoxins (AFB1, AFB2, AFG1, and AFG2) from powdered senna leaves and pods. Detection was performed using high-performance liquid chromatography with fluorescence detection (HPLC-FLD) and pre-column derivatization. The parameters affecting the DLLME extraction efficiency were evaluated. Chloroform (200 µL) was used as an extraction solvent, 500 µL of distilled water was used as a dispersive solvent, and the extraction was performed at pH 5.6 with no salt added. The optimized method was validated using leaves and pods according to the European Commission guidelines. The linear range for all aflatoxins was 2-50 µg/kg, with values for regression coefficients of determination exceeding 0.995. The recoveries of spiked senna leaves and pods were in the ranges of 91.77-108.71% and 83.50-102.73%, respectively. The RSD values for intra-day and inter-day precisions were in the ranges of 2.30-7.93% and 3.13-10.59%, respectively. The limits of detection and quantification varied in the ranges of 0.70-1.27 µg/kg and 2.13-3.84 µg/kg, respectively. The validated method was successfully applied for the quantification of aflatoxins in 60 real samples of dried senna leaves and pods.

Different Extraction Approaches for the Analysis of Melatonin from Cabernet Sauvignon and Feteasca Neagra Wines Using a Validated HPLC-FL Method

In recent years, the wine industry has shown a considerable degree of interest in the occurrence of melatonin in wines. Sample pretreatment may be the most important step in trace analysis. Since wine is a complex matrix and melatonin is present in low amounts (ppb), an adequate extraction technique is required. In this study, the effect of several extraction methods, such as solid phase extraction (SPE), Quick, Easy, Cheap, Effective, Rugged, and Safe extraction (QuEChERS), and dispersive liquid-liquid micro-extraction (DLLME) was studied and the variable parameters that can arise throughout the extraction process were optimized to obtain the best results. A high-performance liquid chromatography with fluorescence detector (HPLC-FL) method was adapted and validated, including measurement uncertainty, for the analysis of melatonin in wines and to assess the efficiency of the extraction yield. After comparing the acquired results, the DLLME method was optimized. Extraction recoveries values ranging from 95 to 104% demonstrated that the approach may be successfully applied for the extraction and concentration (enrichment factor of almost eight) of melatonin in wine samples prior to HPLC-FL analysis. The first report of melatonin levels in Feteasca Neagra wines has been made. The data obtained for Cabernet Sauvignon revealed that the final levels of melatonin in the wines are dependent on the winemaking process.

Detection of bisphenols in Indian surface water, tap water, and packaged drinking water using dispersive liquid-liquid microextraction: exposure assessment for health risk

The prevalence of bisphenols (BPs) has been well documented in the aquatic environment of many countries, but such studies from India are quite limited. The present work aimed to determine the occurrence of BPs in surface water (n = 96), tap water (n = 172), and packaged drinking water (n = 42) and estimate their exposure to humans. For this, a simple, sensitive, cost-effective, and green analytical chemistry method based on dispersive liquid-liquid microextraction (DLLME) was employed. Bisphenol A (BPA) was found as the most prevalent bisphenol (mean concentration range = 980-6470 ng/L) in all the water samples, with a % detection frequency of 17-39%. Bisphenol S (BPS) and bisphenol Z (BPZ) were also detected in all types of water samples. The mean estimated daily intake (EDI) for total BPs (tap water and packaged drinking water) was found to be 474.37 ng/kg b.w./day in adults and 665.65 ng/kg b.w./day in children, respectively. This indicated that the total exposure to all the detected BPs obtained for adults and children was lower than the temporary tolerable daily intake (t-TDI) recommended by the European Food Safety Authority (EFSA) (4 μg/kg b.w./day), thereby posing no substantial risks to humans from consuming water from the tap and/or packaged drinking water.

Deep eutectic solvent-based simultaneous complexation and preconcentration of nickel in Antarctic lake water samples for determination by flame atomic absorption spectrometry

This study presents a simple, sensitive, and accurate method for the determination of nickel by flame atomic absorption spectrometry (FAAS). Prior to instrumental measurement, a deep eutectic solvent-based simultaneous complexation and preconcentration (DES-SCP) method was used to preconcentrate nickel from aqueous solution into measurable quantities. The efficiency of the extraction method was enhanced by forming a non-ionic complex of nickel using dithizone as ligand. By mixing the ligand with the DES extractant, simultaneous complexation and preconcentration of nickel were achieved in a single step. Under optimum conditions of the extraction method, the limit of detection (LOD) and the limit of quantification (LOQ) values were found to be 2.4 and 8.0 ng/mL, respectively. With respect to direct FAAS measurement, the developed method enhanced the sensitivity of nickel determination by about 169 folds. The accuracy and applicability of the developed method were evaluated by performing spike recovery experiments with lake water sampled from Antarctica. Satisfactory recovery results in the range of 94.0-113.7% were recorded and this validated the developed method as an efficient and green alternative for nickel determination.

A dispersive liquid-liquid microextraction followed by reverse-phase high-performance liquid chromatography for QuEChERS determination of chlorogenic acid

INTRODUCTION

The presence of chlorogenic acid (CGA) not only imparts a characteristic flavour to foods but also makes them useful against chronic diseases and metabolic syndromes, especially diabetes mellitus and asthma.

OBJECTIVES

The present study was designed to develop a quick, easy, cheap, effective, rugged, and safe (QuEChERS) and pragmatic method to analyse CGA in plant-based products by applying dispersive liquid-liquid microextraction (DLLME) followed by reverse-phase high-performance liquid chromatography under a diode array detector (RP-HPLC-DAD).

METHODOLOGY

The DLLME was carried out using Triton X-100 as a dispersant and ethanol as an extraction solvent, while method development and validation activities were performed on a Shimadzu 10-AT HPLC-DAD system equipped with C-18 columns as stationary phases.

RESULTS

The well-resolved peak for the standard CGA was observed at 2.92 min for the mobile phase comprising 0.1% aqueous formic acid-ethanol (22:78 v/v) of pH 3.0 programmed under an isocratic flow rate of 1.0 mL/min. The developed method was found to be linear (R²  = 0.9976) over 1-500 μg/mL of CGA concentration at 328 nm. Moreover, the assay was found to be repeatable with RSD ≤ 5.0, and the limit of detection (LOD) and limit of quantification (LOQ) were 0.0281 and 0.0853 μg/mL of CGA, respectively. The DLLME offered an overall recovery rate between 97.60% and 99.54% at an acceptable level of reproducibility [relative standard deviation (RSD) ≤ 5.0].

CONCLUSION

The developed assay was found to be a QuEChERS and pragmatic choice for the high-throughput analysis of CGA in plant-based products/foods. Finally, the analysis revealed the presence of an ample level of CGA in guava fruit in addition to coffee beans and black tea.

Monitoring of sirolimus in the whole blood samples from pediatric patients with lymphatic anomalies

In recent years, off-label use of sirolimus (SIR) has been gaining attention in the clinical practice. However, since it is critical to achieve and maintain therapeutic blood levels of SIR during treatment, the regular monitoring of this drug in individual patients must be implemented, especially in off-label indications of this drug. In this article, a fast, simple, and reliable analytical method for determining SIR levels in whole blood samples is proposed. Sample preparation based on dispersive liquid-liquid microextraction (DLLME) followed by liquid chromatography-mass spectrometry (LC-MS/MS) was fully optimized toward the analysis of SIR and proposed as a fast, simple, and reliable analytical method for determining the pharmacokinetic profile of SIR in whole-blood samples. In addition, the practical applicability of the proposed DLLME-LC-MS/MS method was evaluated by analyzing the pharmacokinetic profile of SIR in whole blood samples obtained from two pediatric patients suffering from lymphatic anomalies, receiving this drug as off-label clinical indication. The proposed methodology can be successfully applied in routine clinical practice for the fast and precise assessment of SIR levels in biological samples, thus allowing SIR dosages to be adjusted in real time during pharmacotherapy. Moreover, the measured SIR levels in the patients indicate the need for monitoring between doses to ensure the optimal pharmacotherapy of patients.

Corona discharge ionization ion mobility spectrometry for ultra-trace determination of methamphetamine extracted from urine and plasma samples by dispersive liquid-liquid microextraction

In this work, dispersive liquid-liquid microextraction (DLLME) based on high-density extraction solvent was applied as a simple, fast and sensitive method for extraction and preconcentration of methamphetamine from human plasma and urine samples. The efficiency of positive corona discharge ionization ion mobility spectrometry was investigated for direct analysis of the extracted analyte. Effective parameters on the extraction efficiency, such as type and volume of the extraction and disperser solvents, centrifugation time, and sample solution pH were optimized. Trichloromethane and isopropanol were selected as the extracting and disperser solvents, respectively. Under the optimized conditions, the linear dynamic range (R² = 0.9969) was found to be 0.5-18 µg/L, and 0.15 µg/L was calculated as the limit of detection. The relative standard deviations of intra- and inter-day were obtained 4 and 10%, respectively, and finally, in the analysis of human plasma and urine samples, the extraction recovery was obtained 104%.

Dataset of PAHs determined in home-made honey samples collected in Central Italy by means of DLLME-GC-MS and cluster analysis for studying the source apportionment

This paper would like to show all the data related to an intensive field campaign focused on the characterization of the Polyaromatic Hydrocarbons (PAHs) composition profile in almost 60 honey samples collected in Central Italy. The analytical data here reported are the base for a study aimed to identify the pollution sources in a region. 22 PAHs were analyzed by means of ultrasound-vortex-assisted dispersive liquid-liquid micro-extraction (DLLME) procedure followed by a triple quadrupole gas chromatograph/mass spectrometer (GC-MS). A chemometrics approach has been carried out for evaluating all the data: in particular, principal component analysis and cluster analysis has been used both for the identification of the main natural/anthropogenic pollutants affecting a site and for evaluating the air quality.

Non-targeted analysis by DLLME-GC-MS for the monitoring of pollutants in the Mar Menor lagoon

Non-targeted analysis for the monitoring of organic pollutants resulting from agricultural and industrial practices, plastics and pharmaceutical products of seawater from the Mar Menor lagoon (SE Spain) is proposed using dispersive liquid-liquid microextraction (DLLME) and gas chromatography-mass spectrometry (GC-MS). Initially, a home-made MS database including 118 environmental organic pollutants, whose presence in different ecosystems has already been reported, was created. The analytical method was applied for the analysis of 42 samples and a total of 18 pollutants were detected and identified. Samples were obtained from different sites around the Mar Menor in three sampling campaigns, enabling the assessment of impact of rain on the input of the detected chemicals and their distribution. In addition, this methodology was validated using a standard mixture containing 54 of the environmental pollutants included in the database, allowing the quantification of the 9 of the identified compounds (dibutyl phthalate, diisobutyl phthalate, diethyl phthalate, bis(2-ethylhexyl) phthalate, anthracene, 2-methylnaphthalene, hexachlorocyclopentadiene, bis(2-ethylhexyl) adipate and oleamide) with concentration between 3 and 271 μg L^-1.

A simple and rapid determination of Al(III) in natural water samples using dispersive liquid-liquid microextraction after complexation with a novel antipyrine-based Schiff base reagent

The purpose of this study is the development of a novel strategy for the determination of Al³⁺ ions using the combination of dispersive liquid-liquid microextraction (DLLME) and UV-Vis spectrophotometry. The method is grounded in the complexation between a novel antipyrine-based Schiff base reagent (EHMP) and Al³⁺ ions. Aluminum concentrations were detected using UV-Vis spectrophotometry at 260 nm and this technique was optimized using the absorbance value of EHMP-Al complex. pH, mixing period, type and volume of organic solvent, etc. were optimized stepwise in order to find out optimum experimental conditions. The limit of detection and the limit of quantification values for the improved analytical method were to be estimated 0.31 and 1.03 μmol.L^-1, respectively. The new strategy was successfully performed to define Al³⁺ ions in natural water samples with RSD values (84.01-107.71%) and recovery values (0.01-0.09%).

Multi-analyte gas chromatography-mass spectrometry method to monitor bisphenols, musk fragrances, ultraviolet filters, and pesticide residues in seafood

A gas chromatography-mass spectrometry method for the analysis of thirty-six anthropogenic contaminants in the edible portion of four distinct seafood items is reported. Considering the heterogeneous composition of algae, mussels, and lean/fatty fish muscles, a generic sample preparation based on the QuEChERS procedure combined with dispersive liquid-liquid microextraction (DLLME) with in situ acetylation was successfully applied for quantification of pesticide residues, bisphenols, musk fragrances and UV-filters. Matrix effects were influenced by the type of seafood, with the lowest effects being observed with EMR-lipid and graphitized carbon black sorbents in dispersive solid-phase extraction cleanup step. Method performance features were successful evaluated in the different seafood samples - algae, mussel, lean and fatty fish muscles, following the criteria established by SANTE/12682/2019 for analytical methods for pesticide residues analysis. The detection and quantification of bisphenol F, musk fragrances (galaxolide and tonalide), UV-filters (2-ethylhexyl salicylate, 2-ethylhexyl 4-methoxycinnamate, and isoamyl 4-methoxycinnamate), and residues of permethrin in commercial samples of algae, mussel and fish collected in a Portuguese estuary support the suitability of the proposed method for future seafood monitoring by food safety authorities.

A fast-screening dispersive liquid-liquid microextraction-gas chromatography-mass spectrometry method applied to the determination of efavirenz in human plasma samples

We demonstrate the suitability of a fast, green, easy-to-perform, and modified sample extraction procedure, i.e., dispersive liquid-liquid microextraction (DLLME) for the determination of efavirenz (EFV) in human plasma. Data acquisition was done by gas chromatography-mass spectrometry (GC-MS) in the selected ion monitoring (SIM) mode. The simplicity of the method lies in, among others, the avoidance of the use of large organic solvent volumes as mobile phases and non-volatile buffers that tend to block the plumbing in high-performance liquid chromatography (HPLC). Chromatographic and mass spectral parameters were optimized using bovine whole blood for matrix matching due to insufficient human plasma. Method validation was accomplished using the United States Food and Drug Administration (USFDA) 2018 guidelines. The calibration curve was linear with a dynamic range of 0.10-2.0 μg/mL and an R² value of 0.9998. The within-run accuracy and precision were both less than 20% at the lower limit of quantification (LLOQ) spike level. The LLOQ was 0.027 μg/mL which compared well with some values but was also orders of magnitude better than others reported in the literature. The percent recovery was 91.5% at the LLOQ spike level. The DLLME technique was applied in human plasma samples from patients who were on treatment with EFV. The human plasma samples gave concentrations of EFV ranging between 0.14-1.00 μg/mL with three samples out of seven showing concentrations that fell within or close to the recommended therapeutic range.

Determination of bisphenols, parabens, and benzophenones in placenta by dispersive liquid-liquid microextraction and gas chromatography-tandem mass spectrometry

Human exposure to endocrine disrupting chemicals (EDCs) is of particular concern during development. Bisphenols, parabens, and benzophenones are EDCs widely used in the manufacture of numerous goods, personal care products, and cosmetics. The aim of this study was to develop a new and practical method for determining three bisphenols, four parabens, and five benzophenones in placenta samples. It uses dispersive liquid-liquid microextraction (DLLME) in combination with gas chromatography-tandem mass spectrometry (GC-MS/MS). Several chemometric approaches were employed to optimize the experimental parameters. Limits of detection ranged from 0.04 to 0.08 ng g^-1 and inter-day variabilities (evaluated as relative standard deviation) from 4.2% to 13.4%. The method was validated using matrix-matched standard calibration followed by a recovery assay with spiked samples. Recovery percentages ranged from 87.1% to 113.2%. Finally, the method was used to measure target compounds in 20 placental tissue samples from voluntary donors. This analytical procedure can provide information on the exposure of the fetus to non-persistent EDCs.

Multivariate optimization of a dispersive liquid-liquid microextraction method for determination of copper and manganese in coconut water by FAAS

In this study, multivariate methodologies were applied in the optimization of a dispersive liquid-liquid microextraction (DLLME) method, aiming at the determination of Cu and Mn in coconut water samples by flame atomic absorption spectrometry. Some extractors (chloroform and CCl₄), dispersants (ethanol, methanol and acetonitrile) and complexing agents (5-Br-PADAP and Dithzone) were previously tested in the extraction. A mixture design was used to optimize the component proportions formed by chloroform (10%), acetonitrile (76%), and 0.020% 5-Br-PADAP solution (14%). Doehlert design optimized the variables pH, NaCl, and buffer amounts for the extraction of both metals. The following analytical characteristics, respectively for Cu and Mn, were accessed: limit of quantification (4.83 and 3.32 µg L^-1), enrichment factors (11 and 8 fold), and precision (6.6 and 6.0% RSD, n = 10). Addition/recovery tests of the analytes allowed to find values in the range of 96.5-120% for Cu and 99-107% for Mn.

Liquid Chromatographic Determination of Trace Bioavailable Neonicotinoids in Soil with Dispersive Liquid-Liquid Microextraction and Its Application for Experimental Monitoring

Dispersive liquid-liquid microextraction (DLLME) was applied to extract bioavailable neonicotinoids involved in the uptake from soil through roots to plants. To quantitatively extract bioavailable neonicotinoids with the proposed DLLME, 3.5 mL of dichloromethane (extractant)/acetonitrile (dispersive solvent) (6:1, v/v) was injected into 5 mL of aqueous soil extracts in which 1 g of sodium chloride was previously dissolved. The separated dichloromethane phase after sonication and centrifugation was evaporated, reconstituted with a mobile phase, and determined with high-performance liquid chromatography. The established method showed sufficient analytical performance to quantify the amount remaining in soil in trace amounts. In a pilot trial conducted in the field, the changes in the concentrations of bioavailable neonicotinoids were confirmed using the method. After showing rapid degradation in soil, degradation of clothianidin and imidacloprid slowed after about 100 days of treatment, but it continued to be detected at around 0.02-0.05 μg/g-dried weight until 1097 days. This result suggests that once these neonicotinoids are treated in soil, they might remain for long periods, which supports the possibilities of crop contamination and exposure to pollinators.

Phthalic acid esters and adipates in herbal-based soft drinks: an eco-friendly method

Phthalic acid esters (PAEs) and adipates are plasticizers with high applicability in several products and building materials (e.g. cosmetics, packing) very persistent in the environment, features which render them ubiquitous pollutants. These substances can contaminate food through the environment (water, air, and soil) and/or migration from packaging materials, which creates a health concern due to their toxicity. This paper describes an eco-friendly dispersive liquid-liquid microextraction (DLLME) procedure to extract five phthalates and bis(2-ethylhexyl) adipate (DEHA) from bottled herbal-based beverages followed by GC-MS/MS quantification. The method showed low limits of detection (5.0-13 μg L^-1) and quantification (20-35 μg L^-1), good inter- and intraday precision (RSD < 19%), and recoveries ranging from 82 to 111%. It was applied to 16 real samples, of which 13 showed the presence of at least one of the analytes under study. Additionally, an exposure assessment was performed, and resulted in a hazard quotient less than 1 (HQ < 1) for all analytes. Therefore, PAEs and DEHA found in samples do not pose a health issue.

Quantification of steroid hormones in human urine by DLLME and UHPLC-HRMS detection

A procedure for the quantification of steroid hormones of various classes in human urine (androgens, estrogens, progestins, corticosteroids) has been described consisting of sample preparation by means of dispersive liquid-liquid extraction after enzymatic hydrolysis with β-glucuronidase from E. Coli followed by ultra-high performance liquid chromatography-high resolution mass spectrometry (quadrupole time-of-flight) detection. Both one-variable-at-a-time and multivariate approaches (full factorial and Box-Behnken designs) were applied to optimize sample preparation conditions. The procedure was validated using synthetic urine in the concentration range of 0.25-500 ng/mL. Then, it was applied to the analysis of real urine samples and the results were compared with those of a common liquid-liquid extraction procedure. The results obtained proved its applicability to the quantification of steroid hormones in human urine with high sensitivity and accuracy.

Sensitive Determination of Acetochlor, Alachlor, Metolachlor and Fenthion Utilizing Mechanical Shaking Assisted Dispersive Liquid-Liquid Microextraction Prior to Gas Chromatography-Mass Spectrometry

A green, sensitive and accurate dispersive liquid-liquid microextraction (DLLME) method was used to preconcentrate four selected pesticides in dam lake water samples for determination by gas chromatography-mass spectrometry (GC-MS). Conditions of the DLLME method were comprehensively investigated and optimized according to type/volume of extraction solvent, type/volume of dispersive solvent, and type/period of mixing. The developed method was validated according to the limits of detection and quantitation, accuracy, precision and linearity. Under the optimum conditions, limit of detection values calculated for alachlor, acetochlor, metolachlor and fenthion were 1.7, 1.7, 0.2 and 7.8 µg/kg (mass based), respectively. The method recorded 202, 104, 275 and 165 folds improvement in detection power values for acetochlor, alachlor, metolachlor and fenthion, respectively, when compared with direct GC-MS measurements. In order to evaluate the accuracy of the developed method, real sample application with spiking experiments was performed on dam lake water samples, and satisfactory percent recovery results in the range of 81%-120% were obtained.

Recent Application of Deep Eutectic Solvents as Green Solvent in Dispersive Liquid-Liquid Microextraction of Trace Level Chemical Contaminants in Food and Water

As growing concerns on green, cost-effective, and time-saving chemistry analysis methods, deep eutectic solvents (DESs) are considered to be promising green alternatives to conventional solvents in dispersive liquid-liquid microextraction (DLLME) of trace level chemical contaminants in food and water, due to their biodegradability, low cost, and simple preparation. In the past few years, numerous innovative researches have focused on preconcentration of trace level chemical contaminants using DESs as extractant. In this context, this review aims to summarize the updated state-of-the-art effort dedicated to preconcentration of trace level chemical contaminants in food and water sample using DESs as extractants in DLLME. Furthermore, the major impact factors affecting the preconcentration efficiency and process mechanisms are thoroughly analyzed and discussed. Finally, prospects and challenges in application of DESs as solvents in DLLME to enrich trace level chemical contaminants are extensively elucidated and critically reviewed.

Multi-phytochemical determination of polar and non-polar garlic bioactive compounds in different food and nutraceutical preparations

Amongst functional foods, garlic and its by-products stand out given their rich phytochemical profile. A comprehensive analytical approach becomes necessary to fully address garlic preparations health-promoting activities, considering the coexistence of several active ingredients from different chemical families. For this, we developed a multi-phytochemical protocol combining Ultrasound and Dispersive Liquid-Liquid Microextraction, coupled to Liquid Chromatography, for the determination of flavonols, organosulfur compounds, and inulin. Hydrophilic interaction chromatography showed an adequate resolution of flavonols and sugars in a shorter time. The protocol showed a suitable performance and acceptable quantitative yields for garlic powder, cooked garlic, black garlic, and liquid garlic flavouring samples. Additionally, the proposed methodology represented a useful tool to assess how the different garlic products related to functional properties, taking into account the various phytochemical families present in each sample. This is the first time a comprehensive and multi-phytochemical validated analysis of garlic preparations is proposed.

Dispersive liquid-liquid microextraction based preconcentration of selected pesticides and escitalopram oxalate, haloperidol and olanzapine from wastewater samples prior to determination by GC-MS

A multivariate experimental design was used to attain optimum conditions of a dispersive liquid-liquid microextraction (DLLME) method for preconcentration of pesticides and pharmaceuticals for determination by gas chromatography mass spectrometry (GC-MS). Experimental design enabled parameters to be evaluated for their effects on extraction output as well as their interactive effects. The optimum parameters suggested by the design model were 200 µL of chloroform, 1.96 mL of ethanol and 40 s vortexing period. Limits of detection and quantification (LOD and LOQ) were calculated using linear calibration plots of the analytes developed in the standard concentration range of 2.0 µg/L-2.0 mg/L. Enhancement in detection power of the analytes recorded by the optimized method with respect to direct GC-MS determination (based on LOD values) was in the range of 3.6 and 539 folds. Spiked recovery experiments for municipal, medical and synthetic wastewater samples yielded low recovery results when calculated against aqueous standard solutions. Matrix matched calibration standards were used to mitigate interferences from the waste samples, and the percent recoveries obtained were close to 100%. This established accuracy and applicability of the developed method.

A new derivatization method for the determination of propineb in black tea and infant formula samples using dispersive liquid-liquid microextraction followed by gas chromatography-mass spectrometry

A novel derivatization method for the determination of propineb by gas chromatography-mass spectrometry (GC-MS) was developed in this study. This was achieved by isothiocyanate derivatization of the analyte by potassium persulfate and potassium carbonate in water medium. Dispersive liquid-liquid microextraction (DLLME) was employed to isolate and preconcentrate the derivatized analyte into an organic phase. All method parameters including concentration/volume of potassium persulfate and potassium carbonate salts, type/period of mixing for derivatization reaction and microextraction process were systematically optimized to lower the detection limit. Under the optimum experimental conditions, the limit of detection (LOD) and limit of quantitation (LOQ) values were calculated as 0.15 mg/kg and 0.52 mg/kg, respectively. The developed method was checked for its accuracy and applicability by spiking black tea and infant formula samples, and the respective percent recovery results were found to be in the range of 99-102% and 98-103%, respectively.

Analytical Scheme for Simultaneous Determination of Phthalates and Bisphenol A in Honey Samples Based on Dispersive Liquid-Liquid Microextraction Followed by GC-IT/MS. Effect of the Thermal Stress on PAE/BP-A Levels

In this paper, an analytical protocol was developed for the simultaneous determination of phthalates (di-methyl phthalate DMP, di-ethyl phthalate DEP, di-isobutyl phthalate DiBP, di-n-butyl phthalate DBP, bis-(2-ethylhexyl) phthalate DEHP, di-n-octyl phthalate DNOP) and bisphenol A (BPA). The extraction technique used was the ultrasound vortex assisted dispersive liquid–liquid microextraction (UVA-DLLME). The method involves analyte extraction using 75 µL of benzene and subsequent analysis by gas chromatography combined with ion trap mass spectrometry (GC-IT/MS). The method is sensitive, reliable, and reproducible with a limit of detection (LOD) below 13 ng g⁻¹ and limit of quantification (LOQ) below 22 ng g⁻¹ and the intra- and inter-day errors below 7.2 and 9.3, respectively. The method developed and validated was applied to six honey samples (i.e., four single-use commercial ones and two home-made ones. Some phthalates were found in the samples at concentrations below the specific migration limits (SMLs). Furthermore, the commercial samples were subjected to two different thermal stresses (24 h and 48 h at 40 °C) for evidence of the release of plastic from the containers. An increase in the phthalate concentrations was observed, especially during the first phase of the shock, but the levels were still within the limits of the regulations.

Mycotoxin Dietary Exposure Assessment through Fruit Juices Consumption in Children and Adult Population

Consumption of fruit juice is becoming trendy for consumers seeking freshness and high vitamin and low caloric intake. Mycotoxigenic moulds may infect fruits during crop growth, harvest, and storage leading to mycotoxin production. Many mycotoxins are resistant to food processing, which make their presence in the final juice product very likely expected. In this way, the presence of 30 mycotoxins including aflatoxin B1 (AFB1), aflatoxin B2 (AFB2), aflatoxin G1 (AFG1), aflatoxin G2 (AFG2), alternariol (AOH), alternariol monomethyl ether (AME), Ochratoxin A (OTA), fumonisin B1 (FB1), fumonisin B2 (FB2), enniatin A (ENNA), enniatin A1 (ENNA1), enniatin B (ENNB), enniatin B1 (ENNB1), beauvericin (BEA), sterigmatocystin (STG), zearalenone (ZEA), α-zearalanol (α-ZAL), β-zearalanol (β-ZAL), α-zearalenol (α-ZOL), β-zearalenol (β-ZOL), deoxynivalenol (DON), 3-acetyl-deoxynivalenol (3-ADON), 15-acetyl-deoxynivalenol (15-ADON), diacetoxyscirpenol (DAS), nivalenol (NIV), fusarenon-X (FUS-X), neosolaniol (NEO), patulin (PAT), T-2 toxin and HT-2 toxin was evaluated in 80 juice samples collected from Valencia retail Market. An efficient Dispersive Liquid-Liquid Microextraction method (DLLME) was carried out before their trace level determination by chromatographic techniques coupled to tandem mass spectrometry. The results obtained revealed the presence of nine mycotoxins namely AOH, AME, PAT, OTA, AFB1, AFB2, AFG2, β-ZAL, and HT2 in the analyzed samples, with incidences ranging from 3 to 29% and mean contents between 0.14 and 59.52 µg/L. Considerable percentages of TDIs were reached by children when 200 mL was considered as daily fruit juice intake.

Simultaneous determination of drug active compound, hormones, pesticides, and endocrine disruptor compounds in wastewater samples by GC-MS with direct calibration and matrix matching strategies after preconcentration with dispersive liquid-liquid microextraction

DLLME was coupled with GC-MS for the simultaneous determination of a drug active compound, hormones, pesticides, and endocrine disruptor compounds with high accuracy and reproducibility in this study. Extraction parameters that affect extraction output including types and volumes of dispersive and extraction solvents, and effect of salt addition were optimized to lower the detection limits for 12 compounds. Under the optimum conditions, LOD and LOQ values were found between 1.99-5.05 and 6.63-16.87 ng/mL, respectively. Spiked recovery tests were also applied to wastewater samples to check the applicability of the method. Matrix matching strategy was used to improve the overall recovery results of the analytes obtained for municipal wastewater. Two different municipal wastewater samples were used in the matrix matching studies. Percent recovery values calculated with the matrix matching experiments were between 85-114%. The results obtained indicated that the developed method could be applied for the determination of the analytes of interest with high accuracy and sensitivity.

A Dispersive Liquid-Liquid Micro-Extraction Technique for the Pre-concentration and Quantification of Vitamin D3 in Milk and Yogurt Samples Using a Non-Aqueous HPLC Method

In present study, a DLLME-HPLC-UV method was developed and validated for the extraction, pre–concentration, and subsequently quantification of vitamin D₃ (Vit D₃) in milk and yogurt samples. In order to be able to extract Vit D₃ from studied samples efficiently, the DLLME procedure was optimized with respect to the parameters affecting the extraction efficacy, where acetonitrile (2 mL as disperser solvent) resulting from the protein precipitation procedure was mixed with 80 µL carbon tetrachloride (as an extraction solvent) respectively. The extracted samples were quantitatively analyzed with a HPLC technique using a C₈ column (250 mm × 4.6 mm, 5 μm) at room temperature (25 °C), mobile phase of acetonitrile/methanol (90:10% v/v) in isocratic elution mode at a flow rate of 1.2 mL/min and UV detection at 265 nm. The method validation results revealed that the method was linear in the concentration range of 2 to 60 ng/mL (r = 0.9997) with a LOD of 0.9 ng/mL and LLOQ of 2 ng/mL; the method was accurate (-2.1% ≤ RE% ≤ +0.6%) and precise (1.2% ≤RSD% ≤ 11.3%) and its recovery was in the range of 86.6 to 113.3%. The obtained results indicated that the method could be utilized as an easy to use technique for the monitoring Vit D₃ in dairy products, especially milk and yogurt samples.

Quantification of PAH4 in roasted cocoa beans using QuEChERS and dispersive liquid-liquid micro-extraction (DLLME) coupled with HPLC-FLD

Roasting is an important process in cocoa production which may lead to formation of non-desirable compounds such as polycyclic aromatic hydrocarbons (PAHs). Therefore, PAH4 (sum of four different polycyclic aromatic hydrocarbons; benz[a]anthracene, chrysene, benzo[b]fluoranthene, and benzo[a]pyrene) in roasted cocoa beans was determined using a modified method (combination of QuEChERS and DLLME), and quantified by HPLC-FLD. The modified method was validated and met the performance criteria required by the EU Regulation (No. 836/2011). Results show a significant (p < 0.05) increase of PAH4 (0.19-7.73 ng/g) with an increase in temperatures (110-190 °C) and duration (10-50 min). The PAHs content in whole cocoa bean roasting was detected even at the lowest temperature (110 °C) compared to nib roasting detected at 150 °C which indicates that PAHs was transferred from dried shells to roasted cocoa beans during the roasting process. The data obtained may help to control and minimize PAH4 formation during cocoa processing.

Spectrometric Smartphone-Based System for Ibuprofen Quantification in Commercial Dosage Tablets

A rapid and portable analytical methodology has been developed for ibuprofen (IBU) quantification in commercial dosage tablets using a spectrometric smartphone-based system. The analytical methodology employs point-of-use approaches both for sample preparation and detection, demonstrating its potential utility for portable quality control of pharmaceutical products. In this work, IBU is dissolved in methanol and then treated with a Co(II) aqueous solution, forming a blue complex which is extractable by dispersive liquid-liquid microextraction. Then, the sample's absorption spectrum is directly measured by a spectrometric smartphone-based system using cartridge made of polyoxymethylene for solvent compatibility. The main experimental factors affecting the dispersive liquid-liquid microextraction of Co-IBU complex were optimized using a multivariate analysis. Under optimized conditions, a working range between 20 and 80 μg mL^-1 was obtained with a correlation coefficient of 0.996 for 5 calibration points. The limit of detection and limit of quantification obtained were 4 and 12 μg mL^-1, respectively. The performance of the proposed methodology was evaluated in commercial tablet dosage forms, and the results demonstrate the ability of the method to determine IBU in samples representative of those used in real-world quality control applications. Recovery values between 97% and 105% were obtained, which are comparable to those obtained via standard titrimetric methodology.

Determination of bisphenol A in red wine using a double vortex-ultrasound-assisted microextraction assay: Role of the interfacial properties

Bisphenol A (BPA) is a synthetic compound broadly used in medical devices as well as in packaging of food and drinks. Recently, BPA toxicity has become of concern to environmental public health. Red wine that is susceptible to BPA contamination is an alcoholic beverage made from yeast fermentation of grapes in the presence of grape skins so as to extract phenolic compounds. The aim of this study was to validate an efficient, low cost, and time-saving method for BPA determination in red-wine beverage. To this end, a rapid and simple microextraction method is here proposed consisting in liquid-liquid separation assisted by a vortex-ultrasound-vortex procedure combined with gas chromatographic analysis (GC-Fid or GC-IT/MS). By means of a comparative study between real red-wine matrix and synthetic hydroalcoholic solutions, different parameters related to the microextraction steps were investigated. The minimal amount of extraction solvent for a given volume of sample was calculated for both the systems. It was demonstrated that for red-wine matrix, the extent of phase separation is strongly affected by some wine constituents and that separation can be tuned by varying the amount of the extraction solvent. This double vortex-ultrasound-assisted method achieved high recovery of BPA and enrichment factor compared with other microextraction methods.

Simultaneous determination of iprodione, procymidone, and chlorflurenol in lake water and wastewater matrices by GC-MS after multivariate optimization of binary dispersive liquid-liquid microextraction

This study reports the optimization of a binary dispersive liquid-liquid microextraction method for the determination of iprodione, procymidone, and chlorflurenol by gas chromatography mass spectrometry. The study was aimed at using two extraction solvents to increase the extraction efficiency of all analytes. The binary solvents recorded results higher than the mono-solvents. After examining the effects of main experimental parameters and their interactions by analysis of variance, 200 μL of binary mixture (dichloromethane and 1,2-dichloroethane), 2.5 mL of ethanol, and 15 s vortex were obtained as optimum parameters. The detection and quantification limits calculated for the analytes were found to be between 0.30-1.6 and 1.0-5.3 ng/mL, respectively. Enhancement in detection power calculated as a ratio of the binary extraction detection limit to the detection limit of direct GC-MS analysis was 105-, 214-, and 233-fold for chlorflurenol, iprodione, and procymidone, respectively. In order to check the accuracy of the developed method, recovery study was performed. Water sampled from a lake and two wastewater samples from treatment facilities were spiked at two concentrations, and the percent recovery calculated for the samples ranged between 87 and 116%. These results confirmed the suitability of the method to real samples for accurate determination of the analytes at trace levels.

Development of an efficient and sensitive analytical method for the determination of copper at trace levels by slotted quartz tube atomic absorption spectrometry after vortex-assisted dispersive liquid-liquid microextraction in biota and water samples using a novel ligand

This study describes the determination of trace levels of copper by slotted quartz tube atomic absorption spectrometry after dispersive liquid-liquid microextraction. A ligand synthesized from the reaction of salicylaldehyde and 1-naphthylamine was used to form coordinate copper complex prior to extraction. All parameters that influence the output of complex formation, extraction, and instrumental measurement were optimized to enhance the absorbance signal of copper. Under the optimum conditions, about 104-fold enhancement in sensitivity was recorded over the conventional flame atomic absorption spectrometer, corresponding to a 0.51 ng/mL detection limit. The percent relative standard deviation calculated for the lowest concentration (4.8%) indicated high precision for the experimental procedure. Accuracy and applicability of the optimum method were determined by performing spiked recovery tests on urine, lake water, and mineral water samples. Satisfactory recovery results were obtained between 82.2 and 106.3% at four different concentrations. Matrix matching method was also performed to increase the accuracy of quantification, and the percent recovery calculated for 175 ng/mL was 105.14%.

Evaluation of the Impact of Storage Conditions on the Biogenic Amines Profile in Opened Wine Bottles

A survey of biogenic amine (BA) profiles in opened wine bottles has been established to monitor the level of biogenic amines (BAs) in opened bottles against time and other conditions. Bottles of red and white wine were submitted to different temperatures, stopper type (screw cap, cork), and use of vacuum devices. A total of six wines made from a variety of grapes were obtained from vineyards from regions across Poland. Dispersive liquid-liquid microextraction-gas chromatography-mass spectrometry (DLLME-GC-MS) procedure for BAs determination was validated and applied for wine sample analysis. The total content of BAs from the set of immediately opened wine samples ranged from 442 to 929 µg/L for white wines, and 669 to 2244 µg/L for red wines. The most abundant BAs in the analysed wines were histamine and putrescine. Considering the commercial availability of the analysed wines, there was no relationship between the presence of BAs in a given wine and their availability on the market. However, it was observed and confirmed by chemometric analysis that the different storage conditions employed in this experiment affect not only the BAs profile, but also the pH.

Use of Innovative (Micro)Extraction Techniques to Characterise Harpagophytum procumbens Root and its Commercial Food Supplements

INTRODUCTION

For the determination of harpagoside and the wide phenolic pattern in Harpagophytum procumbens root and its commercial food supplements, dispersive liquid-liquid microextraction (DLLME), ultrasound-assisted DLLME (UA-DLLME), and sugaring-out liquid-liquid extraction (SULLE) were tested and compared.

OBJECTIVES

In order to optimise the extraction efficiency, DLLME and UA-DLLME were performed in different solvents (water and aqueous solutions of glucose, β-cyclodextrin, (2-hydroxypropyl)-β-cyclodextrin, sodium chloride, natural deep eutectic solvent, and ionic liquid).

MATERIAL AND METHODS

The plant material was ground and sieved to obtain a uniform granulometry before extraction. Commercial food supplements, containing H. procumbens are commercially available in Italy.

RESULTS

The most effective sodium chloride-aided-DLLME was then optimised and applied for analyses followed by HPLC-PDA. For comparison, microwave-assisted extraction was performed using the same solvents and the best results were obtained using 1% of β-cyclodextrin or 15% of sodium chloride.

CONCLUSION

All commercial samples respected the European Pharmacopoeia monograph for this plant material, showing a harpagoside content ≥ 1.2%. Copyright © 2017 John Wiley & Sons, Ltd.

Development and Validation of a Sensitive Method for Trace Nickel Determination by Slotted Quartz Tube Flame Atomic Absorption Spectrometry After Dispersive Liquid-Liquid Microextraction

In this study, dispersive liquid-liquid microextraction was systematically optimized for the preconcentration of nickel after forming a complex with diphenylcarbazone. The measurement output of the flame atomic absorption spectrometer was further enhanced by fitting a custom-cut slotted quartz tube to the flame burner head. The extraction method increased the amount of nickel reaching the flame and the slotted quartz tube increased the residence time of nickel atoms in the flame to record higher absorbance. Two methods combined to give about 90 fold enhancement in sensitivity over the conventional flame atomic absorption spectrometry. The optimized method was applicable over a wide linear concentration range, and it gave a detection limit of 2.1 µg L^-1. Low relative standard deviations at the lowest concentration in the linear calibration plot indicated high precision for both extraction process and instrumental measurements. A coal fly ash standard reference material (SRM 1633c) was used to determine the accuracy of the method, and experimented results were compatible with the certified value. Spiked recovery tests were also used to validate the applicability of the method.

A green deep eutectic solvent dispersive liquid-liquid micro-extraction (DES-DLLME) for the UHPLC-PDA determination of oxyprenylated phenylpropanoids in olive, soy, peanuts, corn, and sunflower oil

A green dispersive liquid-liquid microextraction (DLLME) using deep eutectic solvent (DES) as the extracting solvent has been developed and applied for the simultaneous quantification of ferulic acid, umbelliferone, boropinic acid, 7-isopentenyloxycoumarin, 4'-geranyloxyferulic acid (GOFA), and auraptene in some vegetable oils using ultra high performance liquid chromatography (UHPLC) with photodiode array detection (PDA). All parameters in the extraction step, including selection and loading of both extracting and dispersing solvents, amount of both extractant and disperser solvent were investigated and optimized. PhAA/TMG DES achieved higher recovery and enrichment factor compared to other DESs. The validated method showed good linearity with correlation coefficients, r²>0.9990 for all the analytes. Furthermore, this is the first time that eco-friendly solvents are used for the extraction of oxyprenylated phenylpropanoids and the corresponding extract analyzed with ultra high performance liquid chromatography with photodiode array detection.

Alterations in liver marker enzymes and recovery ability of cyprinids as indicators of aquatic pollution

Information on the detection of pesticides in fresh water Lakes of Kashmir (Dal and Mansbal) through GC-MS technique is scarce, and also the recovery in biochemical parameters (AST, ALT and ALP) of fish after transferring them to clean media has not been reported yet. The water samples were collected from three sites and analyzed for their pesticide profile by dispersive liquid-liquid micro extraction (DLLME) followed by GC-MS. Influence of pesticides on liver marker enzymes of Cyprinus carpio and Carassius carassius was also investigated. The results obtained showed the presence of three main pesticides viz. chlorpyrifros, dimethoate and dichlorvos in waters of Dal Lake whereas no pesticide was detected in waters of Mansbal. The higher values for AST, ALT and ALP activities and decrease in protein content were obtained in the samples from the Dal Lake compared with those from Mansbal Lake (p < 0.05). These data when compared with the values found in C. carpio and C. carassius from both the Dal Lake and Mansbal Lake kept under laboratory conditions after 15, 30, 45 and 60 days of maintenance in clean media found that during depuration, all the enzyme activities came down significantly (p < 0.05) indicating the compensatory response by the fish against the pesticide stress. Therefore, these parameters could be used as indicators of pesticide pollution in aquatic organisms and were recommended for environmental monitoring for investigating the mechanism involved in the recovery pattern.

Occurrence of cocaine and metabolites in hospital effluent - A risk evaluation and development of a HPLC method using DLLME

A fast method for the determination of cocaine and its metabolites in hospital effluent samples was worked out by using liquid chromatography with the aid of fluorescence and diode array detection. Solid phase extraction and dispersive liquid -liquid microextraction were employed during the sample preparation stage. The experiment was conducted by using Chromabond^® C18 ec 6 ml/500 mg cartridges, with recoveries higher than 96.6%, 88.3%, 78.7%, and LOQ_m 0.15; 0.18 and 0.30 μg L^-1 for cocaine, benzoylecgonine and anhydroecgonine respectively. In the case of DLLME, different chemical conditions and solvent combinations were tested to find the best settings for the microextraction: pH 9; addition of 0.3 mol L^-1 NaCl; 150 μL extractor (chloroform) and 350 μL disperser (methanol). The recoveries for cocaine were as high as 98.3% with LOQ_m 0.3 μg L^-1. After validation, these methods were applied to quantification of the analytes. While the concentration of the anhydroecgonine, (the main pyrolytic metabolite of cocaine), remained below the limit of detection, the range of concentrations of cocaine and benzoylecgonine determined were 0.4-4.9 μg L^-1 and 0.9-8.6 μg L^-1, respectively. The occurrence has a relatively median/high environmental impact. These concentration values suggest that a role is played by other sources of cocaine, probably related to transport, or handling and the consumption of the drug. The outcome is that cocaine can be quantified by using DLLME as well as SPE, however, DLLME offered clear benefits like simplicity, affordability, and speed, as well as only requiring a small volume of solvents and samples.

Fast analysis of phthalates in freeze-dried baby foods by ultrasound-vortex-assisted liquid-liquid microextraction coupled with gas chromatography-ion trap/mass spectrometry

This paper is focused on the determination of phthalates (PAEs), compounds "plausibly" endocrine disruptors, in baby food products by means of a method based on ultrasound-vortex-assisted liquid-liquid microextraction coupled with GC-IT/MS (UVALLME-GC-IT/MS). Particularly, the whole procedure allows the determination of six phthalates such as DMP, DEP, DBP, iBcEP, BBP and DEHP. After dissolution of 0.1g product sample and addition of anthracene as Internal Standard, 250μL of n-heptane are used as extraction solvent. The solution, held for 5min on the vortex mixer and for 6min in an ultrasonic bath at 100W for favoring the solvent dispersion and consequently the analyte extraction, is centrifuged at 4000rpm for 30min. About 100μL of heptane are recovered and 1μL is injected into the GC-IT/MS. All the analytical parameters investigated are deeply discussed: under the best conditions, the percentage recoveries range between 96.2 and 109.2% with an RSD ≤10.5% whereas the Limit of Detections (LODs) and the Limit of Quantifications (LOQs) are below 11 and 20ngg^-1, respectively, for all the PAEs except for iBcEP (23 and 43ngg^-1, respectively). The linear dynamic range of this procedure is between 10 and 5000ngg^-1 with R² ≥0.92. The method has been applied to real commercial freeze-dried samples (chicken and turkey meats) available on the Italian pharmaceutical market: three PAEs were preliminary identified, i.e. DEP (14ngg^-1), DBP (11ngg^-1) and DEHP (64ngg^-1).

An in situ derivatization - dispersive liquid-liquid microextraction combined with gas-chromatography - mass spectrometry for determining biogenic amines in home-made fermented alcoholic drinks

A novel dispersive liquid-liquid microextraction (DLLME) gas chromatography mass-spectrometry (GC-MS) method was developed for the determination of 13 biogenic amines in home-made wine samples. The method allows to simultaneous extraction and derivatization of the amines providing a simple and fast mode of extract enrichment. During the study, two different procedures were examined. Statistical analysis was performed to choose better procedure, as well as the conditions of derivatization reaction. At least, a mixture of methanol (dispersive solvent; 215μL), chloroform (extractive solvent; 400μL), and isobutyl choloroformate (derivatizing reagent; 90μL) was used as extractive/derivatizing reagent, added to 5mL of sample. The addition of mixture of pyridine and HCl was necessary to eliminate the by-products. The proposed method showed good linearity (correlation coefficients >0.9961), good recoveries (from 77 to 105%), and good intra-day precision (below 13%) and inter-day precision (below 10%). Moreover, detection limits were never over 4.1μg/L. The developed method was successfully applied to the analysis of 17 home-made wine samples not regulated by law. All of the biogenic amines analyzed were found in most of the wines.

Multimycotoxin analysis in water and fish plasma by liquid chromatography-tandem mass spectrometry

High performance liquid chromatography-mass spectrometry was used for the determination of 15 mycotoxins in water and fish plasma samples, including aflatoxins, fumonisins, ochratoxin A, sterigmatocistin, fusarenon-X and emerging Fusarium mycotoxins. In this work, dispersive liquid-liquid microextraction (DLLME) was assessed as a sample treatment for the simultaneous extraction of mycotoxins. Results showed differences in recovery assays when different extraction solvents were employed. Ethyl acetate showed better recoveries for the major part of mycotoxins analyzed, except for aflatoxins B2, G1 and G2, which showed better recoveries when employing chloroform as extractant solvent. Fumonisins and beauvericin exhibited low recoveries in both water and plasma. This method was validated according to guidelines established by European Commission and has shown to be suitable to be applied in dietary and/or toxicokinetic studies in fish where is necessary to check mycotoxin contents in rearing water and fish plasma.