QuEChERS Extraction Research Articles

Determination of non-glucosidic cyanogen in Chinese liquor-fermentation ingredients using QuEChERS sample preparation and spectrophotometric method

Non-glucosidic cyanogen, which easily break down to liberate toxic cyanide ions, present in sorghum, wheat and fermented grains involved in Chinese liquor fermentation affect its quality and safety, and may endanger public health. In this study, a simple and practical method for the determination of non-glucosidic cyanogen was developed using QuEChERS sample-preparation, combined with spectrophotometry. The QuEChERS extraction solvent, buffer and SPE adsorbents were varied to optimize analyte recovery from spiked samples. Under the optimum conditions, the linear range for cyanide determination was 0.02–0.44 μg/mL, with a correlation coefficient of 0.99 and an LOD of 0.0023 μg/mL. The recoveries of spiked sample (82.11–115.12%) and the relative standard deviations (RSDs; 4.87–9.62%) were considered satisfactory. The method was successfully applied to real samples and was simple, efficient, inexpensive, practical and reliable.

Determination of Chlorpyrifos Pesticide Residue in Bell Peppers Grown in Dalat (Vietnam) by GC-MS/MS Using QuEChERS Extraction

Determination of Chlorpyrifos Pesticide Residue in Bell Peppers Grown in Dalat (Vietnam) by GC-MS/MS Using QuEChERS Extraction

Development and Validation for Simultaneous Determination of Disulfoton and Its Five Metabolites in Seven Agro-Products Using Liquid Chromatography-Tandem Mass Spectrometry Combined with QuEChERS Extraction Method

Development and Validation for Simultaneous Determination of Disulfoton and Its Five Metabolites in Seven Agro-Products Using Liquid Chromatography-Tandem Mass Spectrometry Combined with QuEChERS Extraction Method

Tocopherols in Seeds and Nuts: QuEChERS Extraction, HPLC Separation, and Fluorescence Detection

Tocopherols in Seeds and Nuts: QuEChERS Extraction, HPLC Separation, and Fluorescence Detection

Pesticide residues in dates using a modified QuEChERS method and GC-MS/MS

ABSTRACT The aim of this study was to develop a convenient, fast, effective and safe analytical method (QuEChERS) to determine 198 pesticide residues in multi-source date palm fruits using gas chromatography-tandem mass spectrometry (GC-MS/MS). The calibration curves for most pesticides were linear in the range of 15–150 µg/kg, with r2 values higher than 0.9934 and the relative standard deviation for all pesticides was ≤20%. The mean recovery rate of pesticides was 70–120% and limits of detection (LODs) and limits of quantification (LOQs) were in the range of 5–14 µg/kg and 14–40 µg/kg, respectively. The validated procedure was used to monitor pesticide residues in 30 fresh date samples. It could be concluded that the modified QuEChERS extraction method was efficient in analysing pesticide residues in dates palm and none of the samples contained residues above the MRLs.

Seasonal and geographical variations in insecticide and miticide residues in hop samples produced across three hop-growing regions in the Czech Republic during the years 2018–2020

The aim of this study was to determine the presence of zoocide (insecticide and miticide) residues in hops collected in three hop-growing regions located in the Czech Republic, and to assess their zoocide profiles and residue levels in terms of variability in temperature and precipitation across the 2018–2020 seasons. Furthermore, the weather factors that influenced the occurrence of hop pests are described and discussed. During our 3-year survey, a total of 120 samples of whole-cone hops samples harvested in three hop-growing regions were analysed for the presence of 29 insecticides and miticides using the modified QuEChERS extraction method, followed by liquid chromatography-tandem mass spectrometry and gas chromatography-tandem mass spectrometry. A majority, 119 of 120 samples, contained a residue of at least one of the active substances surveyed in this study, and 34 analysed samples contained multiple residues with three to four zoocides presented. Concerning the most frequently detected zoocide residues, spirotetramat and/or its metabolites were found in 94.2% of the samples at levels ranging from 0.02 to 1.08 mg/kg. Of the other zoocides surveyed, residues of fenpyroximate, hexythiazox, bifenazate and lambda-cyhalothrin were routinely found in hop cone samples. Obtained data were then used for evaluating seasonal and geographical variations in the profile of zoocide residues among the hop-growing regions in the years 2018–2020, and the compliance with legal regulations concerning the use of zoocides on hops was ascertained. The results showed that (1) the profile and levels of zoocide residues found in the samples reflected seasonal prevalence of pest infestation on hop plants; (2) the strategy to control pests (especially aphids) used in most of hop yards was consistent across the seasons; and (3) a concentration of spirotetramat residues less than 1 mg/kg was typical for hops grown in the Czech Republic.

QuEChERS extraction for quantitation of bitter acids and xanthohumol in hops by HPLC-UV

We hypothesised that QuEChERS could be successfully applied to the extraction of bitter acids and xanthohumol from hops, which would be less time consuming, cheaper, and more eco-friendly by the severe reduction of solvent use. High performance liquid chromatography was used to separate the compounds after extraction and quantitation was evaluated against standard calibration curves for bitter acids prepared from an International calibration extract (ICE-4) and an authentic standard of xanthohumol. The standard QuEChERS method was compared to mini and micro-versions including clean-up and spiking procedures. The quantitative analyzes indicate the applicability of the QuEChERS method for the quantitation of bitter acids compared to Soxhlet extraction. The statistical data confirm reproducibility of the total alpha- and beta- acids measured by the standard method and the modified mini- and micro-QuEChERS procedures. Our hypothesis is supported by the data described and is consistent with other previous methods described in the literature.

Modification and validation of the simultaneous detection of 38 pesticide residues method by ultra‐high‐performance liquid chromatography/tandem mass spectrometry with QuEChERS extraction in different oil crops and products

Oil crops and products are important food materials in daily life. Pesticide residues in food could directly and indirectly endanger human health. However, the method for detecting multiple pesticides simultaneously is limited. In this study, an easy and efficient method for the simultaneous determination of 38 pesticides in oil crops and products was established and validated. All samples were treated with a modified QuEChERS procedure followed by ultra-high-performance liquid chromatography/tandem mass spectrometry (UHPLC/MS/MS) analysis. Mass spectrometry was performed in positive and negative ion electrospray ionization mode. The mobile phase consisted of 0.1% formic acid in water and 0.1% formic acid in acetonitrile. The column used was a Poroshell 120 EC-C18 and the flow rate was 0.3 mL/min. The method was validated so that the calibration curves for all pesticides had good linearity in the concentration range of 10-1000 μg/L with correlation coefficients (R2 ) above 0.9945. The recovery rates were between 70.1 and 120.0%, with relative standard deviations (RSDs) (n = 6) ≤20.0%. The limits of quantification (LOQs) ranged from 0.5 to 10 μg/kg, limits of detection (LODs) ranged from 2.0 to 30 μg/kg, and the matrix effect (ME) ranged from -18.77 to 19.33%, respectively. The method proved to be accurate, sensitive, and stable. It can be used for rapid screening and confirmation of 38 pesticide residues in oil crops and products which takes 10 min for sample extraction and clean-up with less requirement of solvents. This study provides a technical basis for regulatory analysis and quality supervision of foods.

Optimization and Validation of a Method Based on QuEChERS Extraction and Gas Chromatographic-Mass Spectrometric Analysis for the Determination of Polycyclic Aromatic Hydrocarbons and Polychlorinated Biphenyls in Olive Fruits Irrigated with Treated Wastewaters

The wastewater reuse is an important measure to face water shortage, thus improving the resilience of agricultural production chains. However, treated wastewater can contain residual organic micropollutants residues that may result in crop contamination. Among edible crops, olive is the most important agricultural product in the Mediterranean region. Methods to assess the contamination of organic micropollutants such as polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) in olives are poorly investigated. Given the complexity of olives, this study focused on the development and validation of a method for the simultaneous extraction of PAHs and PCBs from olives, and subsequent analysis by gas chromatography coupled with mass spectrometry detection. Extraction was optimized through a QuEChERS protocol, studying the effect of the extraction solvent (CH2Cl2, cyclohexane, CH3CN) and of the dispersive-solid phase extraction (d-SPE) sorbent (octadecyl silica, Florisil, primary secondary amine, Z-Sep) on the recovery of micropollutants. The best recoveries (94–122%, relative standard deviations below 5%) were obtained using CH3CN/H2O and a double purification step with Z-Sep and Florisil. The method developed for PAHs and PCBs, which showed good intra-day (<2.7%) and inter-day (<2.9%) precision and low matrix effect (|ME| < 14%), was applied to the analysis of olives grown by irrigation with reclaimed wastewaters.

Neonicotinoids exposure assessment in Africanized honey bees (Apis mellifera L.) by using an environmentally-friendly sample preparation technique followed by UPLC-MS/MS

A miniaturized QuEChERS extraction method followed by ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) was developed to analyze thiamethoxam and imidacloprid in 0.3 g of lyophilized Africanized honey bees (Apis mellifera L.). The work aimed to estimate honey bees' exposure to pesticides at the nanogram/gram (ng g−1) levels, using small sample and reagent quantities. Low amounts of solvents and salts were employed – 15× less than used in traditional methods. Average recoveries ranged from 64.5% to 99.7%, with repeatability below 20% for samples spiked at 3 and 167 ng g−1. LOD and LOQ were 0.7, and 3 ng g−1 for both pesticides. Applying the proposed approach, honey bee samples from different apiaries from the State of São Paulo (Brazil) were analyzed. The pesticides were detected in concentrations between 7.0 and 27.0 ng g−1. Thus, the proposed method can be used as a greener alternative to analyze the two neonicotinoids at trace levels in small quantities of bees, consequently saving chemicals and waste.

Multi-Residue Analysis of Chemical Additives in Edible Vegetable Oils Using QuEChERS Extraction Method Followed by Supercritical Fluid Chromatography.

Since the quality and safety of food highly depend on its preservation and protection, the use of food packaging materials increases the risk of chemical contamination of the packaged food by migration. Herein, we focused on antioxidants, photoinitiators, UV absorbers and plasticizers which are extensive additives used in food packaging materials. In the present study, a rapid, simple, green and reliable method was developed and validated for the determination of twelve chemical additives in edible vegetable oils using SFC together with a modified QuEChERS procedure. Under the optimum conditions, twelve additives were separated within 10 min, and the consumption of the organic solvent was significantly reduced, which improved the environmentally friendliness. The performance of the developed method was evaluated. Good linearity (r > 0.999) was obtained in the range of 0.20–20.0 µg/mL and 0.50–20.0 µg/mL, respectively. The limits of detection and limits of quantification of the twelve additives in vegetable oils were 0.05–0.15 µg/mL and 0.15–0.50 µg/mL, respectively. Recoveries of all the chemical additives for the spiked samples were between 60.9% and 106.4%, with relative standard deviations (RSD) lower than 9.9%. The results demonstrated that the proposed method was efficient, reliable and robust for the routine analysis of additives in edible vegetable oils and can be an alternative to the multi-residue analysis of chemical additives for other packaged foods.

Investigation and probabilistic health risk assessment of pesticide residues in cucumber, tomato, and okra fruits from Khuzestan, Iran.

In this study, 30 pesticide residues in 45 fresh-eating cucumber, tomato, and okra fruit samples collected from the Khuzestan province as the main agricultural products in Iran using the QuEChERS extraction method were analyzed. In addition, noncarcinogen and carcinogen health risk assessments were evaluated. Results indicated that 93% of cucumber samples had at least one pesticide, of course, less than the maximum residue limit (MRL). All tomato and okra fruit samples were contaminated by diazinon. All pesticides detected in tomato samples were below national MRL except for thiamethoxam in four samples. In okra fruit samples, all detected diazinon and malathion, but only tebuconazole fungicide exceeded MRL. In addition, the hazard index (HI) was 0.23 and 1.06 in cucumber samples, 0.33 and 1.51 in tomato samples, and 5.5E-03 and 0.025 in okra fruit samples in adults and children, respectively. The use of cucumber and tomato may have notable risks in the short term in children group age. Ranking based on total CR was 1.2E-05 in tomato, 7.7E-06 for cucumber, and in okra 9.1E-11 because of the difenoconazole residue. However, significant carcinogenic risk threatens cucumber and tomato consumers.

Simultaneous multi-residue pesticide analysis in southern Brazilian soil based on chemometric tools and QuEChERS-LC-DAD/FLD method.

A simple and straightforward QuEChERS extraction method was proposed for the simultaneous determination of atrazine (ATZ), desethylatrazine (DEA), desisopropylatrazine (DIA), carbaryl (CBL), carbendazim (CBD), and diuron (DIU) in soil with high agricultural activity from southeastern Brazil, using high-performance liquid chromatography-diode-array detection/fluorescence detection. Screening studies carried out by 24 factorial design indicate better recoveries when less sample (1.0g) and the volume of solvent (2.0mL of ACN) were applied, compared to the original QuEChERS method. Furthermore, interactions between factors were not negligible in the experimental set, except for ATZ and DIU, in which only water volume influenced their recovery. The influence of the type (primary secondary amine (PSA), C18, and Florisil) and the sorbent amount ratio to the compounds' concentration were also considered. PSA (25mg) was selected as the best sorbent without losing analytical response. The limits of quantification (LOQ) were estimated to be 5.0 to 15µgkg-1 in the soil matrix. Analytical performances were consistent with linearity (R2 ≥ 0.998), recovery from 74.7 to 108%, and relative standard deviations (RSD) between 2.6 and 20.2%. Robustness was assessed by fractional factorial Plackett-Burman design. The method is recommended for chemicals that are soluble in water, and it was successfully applied in the analysis of real soil samples containing the analytes in the range of μg kg-1, proving to be suitable for the study of soils strongly impacted by agricultural activity.

Occurrence of mycotoxins and mycotoxigenic fungi in silage from the north of Portugal at feed-out

Maize and grass silages are important dietary components for ruminant livestock that influence the quality of animal products for human consumption, such as milk, in many parts of the world. Infection of plants by fungi able to produce mycotoxins, either in the field or post-harvest, can result in a decrease of silage nutritional quality and, consequently, in milk quality. In this study, 45 maize and grass silage samples were collected from 25 dairy farms located in the north of Portugal. The occurrence of fungi was evaluated in samples, the most frequently isolated species being Aspergillus fumigatus, Dipodascus geotrichum, Mucor circinelloides, Penicillium paneum, and Aspergillus flavus. The mycotoxigenic profile of the fungal species was studied using the ultra-high-performance liquid chromatography coupled to mass spectrometry–ion trap–time-of-flight (UHPLC–MS–IT–TOF) detection. In addition, a new method based on a QuEChERS extraction followed by the UHPLC- tandem mass spectrometry (UHPLC-MS/MS) detection was developed for simultaneous analysis of 39 mycotoxins in silage. A high co-occurrence of Fusarium mycotoxins was found, although at low levels of contamination. Deoxynivalenol and beauvericin were found in more than 82% of maize silage samples. It can be highlighted the low occurrence of Penicillium and Aspergillus toxins in the maize and grass silages studied despite the frequent detection of species of both genera.

Sarımsakta Organoklorlu Pestisit Kalıntılarının Tespiti ve Sağlık Risklerinin Değerlendirilmesi

Persistent organic polluting pesticides that have been used extensively historically can still be detected in agricultural products and cause health risks. In this study, banned organochlorine pesticide (OCP) residue levels in 23 garlic samples produced in the fields of different villages located in the potentially polluted area in the center of Kastamonu were determined by GC/MS method combined with QuEChERS extraction and clean-up technique. In our study, at least one OCP was detected in 14 of 23 samples and 20 of the 23 OCPs we examined in our study, were detected in at least one sample. The most frequently detected OCP residue in garlic is dichloro-diphenyl-trichloroethane (DDT) and its metabolites. The residue levels of all garlic samples were below their maximum residue levels (MRL), except for sample 16. Eighteen of the OCPs we examined in our study, were determined in sample 16 and 14 of them had very high concentrations. Estimated daily intake levels (EDI) of all samples were calculated to determine whether the acceptable daily intake (ADI) levels were exceeded in order to make a risk assessment. None of the EDI values calculated from the amounts of residues in the sample 16 exceeded the ADI levels. However, it should not be forgotten that samples such as sample 16 may pose a risk of exposure for people whose actual consumption of garlic is higher than the calculated amount.

Quantification of docusate antimicrobial finishing after simulated landfill degradation via tandem mass spectrometry and QuEChERS extraction.

An analytical method for the detection and quantification of silver docusate antimicrobial finishing in soil was developed through a combination of the QuEChERS extraction method and tandem mass spectrometry (MS/MS) quantification with isotopically labeled internal standard. First, the calibration system was established in the matrix where QuEChERS extraction removed docusate from soil. The addition of an isotopically labeled internal standard reduces ionization suppression due to instrumental fluctuation and run-to-run deviation. After establishing the calibration system, this quantification method was validated according to a guideline from the U.S. Food and Drug Administration. A series of variables for quantification were validated including coefficient of determination (R2 = 0.989 ± 0.002), percent error (% error = 3 ± 4%), coefficient of variation (% CV = 6 ± 1%), limit of detection (LOD = 8 ± 2 ng mL-1), lower limit of quantification (LLOQ = 27 ± 5 ng mL-1), recovery and matrix effect (matrix effect = 0.944 ± 0.026). Those parameters were obtained from the inter- and intra-day measurements for both calibration and the quality control standards. Later, samples extracted from a simulated landfill degradation of cotton fabrics applied with sliver docusate antimicrobial finishing were measured. It was observed that the concentration measured (51 ± 5 ng mL-1 or 252 ± 25 ng g-1) fell into the ranges defined by the method development with good precision (% CV = 4 ± 1%). Results from this study could further the understanding of textile landfill degradation and facilitate further study regarding docusate contamination in soil.

Automated multi-plug filtration cleanup method for analysis of 48 pesticide residues in green tea using liquid chromatography-tandem mass spectrometry

An automated multi-plug filtration cleanup (m-PFC) method, based on QuEChERS extraction was developed for the analysis of 48 pesticides in green tea. The carboxyl functionalized multi-walled carbon nanotubes (MWCNTs-COOH) were firstly packed in m-PFC columns and functioned as promising sorbents with better clean-up capability. The different parameters of automated m-PFC equipment and extraction conditions were optimized. The automated method integrated cleanup and filtration (through filter membrane) procedure into a single run before injected to the detection instrument. Comparison to d-SPE and manual m-PFC method, the automated method could handle a batch of samples simultaneously with better purification effect. Acceptable recoveries at three concentration levels from 71% to 114% were obtained (except carbendazim and bifenazate) with relative standard deviations lower than 18%. The proposed automated m-PFC method offered a great compromise between rapidity, convenience and efficiency. It was successfully applied for market monitoring of pesticide residues with robust analyze data. • Automated m-PFC method for analysis of 48 pesticides in green tea. • Functionalized MWCNTs were mixed with other sorbents to assess cleanup performance. • Extraction and automated m-PFC process were optimized by recovery and matrix effect. • Method validation showed superior purification efficiency and robust analysis data. • The automated method can handle a batch of real sample in routine pesticide analysis.

Determination of Pesticide Residues Using QuEChERS Extraction with Inert GC-MSD Analytical Technique and Application on Seasonal Fruits and Vegetables in Pakistan

Determination of Pesticide Residues Using QuEChERS Extraction with Inert GC-MSD Analytical Technique and Application on Seasonal Fruits and Vegetables in Pakistan

Multi-residue analysis for the determination of pesticide residues in fruit and vegetables using liquid chromatography coupled with mass spectrometry

This article summarizes the results of validation studies of a multi-residue method for the determination of pesticide residues in fruits and vegetables. The results of some of the monitoring control programs carried out in Romania are also presented. Liquid chromatography coupled with mass spectrometry (LC-MS / MS) was used to assess pesticide residue levels. The QUECHERS extraction method was used to extract the compounds. To validate the method, the control samples were fortified with a solution of 74 pesticides for LC-MS / MS analyzes, at 3 levels.The validation study is based on the regulations in Document DG Nº SANTE / 12682/2019. The scope of validation included the following performance requirements: Limit of detection; Quantification limit; Recovery; Fidelity; Repeatability; Reproducibility; Recovery; Selectivity / Specificity; Stability / Robustness; Linearity; Matrix effect; Measuring the margin of error.

Quechers approach to the Alternaria mycotoxins detection in wheat: The recovery study

The performance of the QuEChERS extraction followed by the LC-MS/ MS analytical method was evaluated in terms of Alternaria mycotoxins recovery from the wheat. The alternariol (AOH), tentoxin (TEN) and alternariol monomethyl ether (AME) were analyzed using the ESI+ (electrospray positive ionization) by multiple reactions mon?itoring mode (MRM). In order to determine the recovery, the blank wheat samples were spiked at two spiking levels (0.01 and 0.1 mg/kg) in six replicates. The obtained average recoveries and precisions (expressed as the RSDr, %) were as follows: 107.6% (RSDr of 6.84%) for alternariol, 108.0% (RSDr of 6.78%) for tentoxin and 110.1% (RSDr of 6.50%) for alternariol monomethyl ether. The results of this study were in accordance with the Commission Decision 2002/657/EC and Commission Regulation (EC) No 401/2006.