Quick, Easy, Cheap, Efficient, Rugged And Safe Research Articles

Quantification of hetero-cyclic amines from different categories of braised beef by optimized UPLC-TQ-XS/ESI method.

This research work has developed and optimized a sensitive analytical method for separation and quantification of heterocyclic amines (HCAs) mainly including PhIP, Harman, Norharman, IQ, MeIQ, AαC, MeAαC and Trp-P-2 by optimizing UPLC-TQ-XS using electrospray ionization source (ESI+) on ACQUITY UPLC® BEH C18 column in <7min, from braised beef sample matrix. Meanwhile, modified HCAs extraction by modifying QuEChERS (quick, easy, cheap, efficient, rugged and safe) technique and revisited with solid phase extraction (SPE) for HCAs purification, instead using traditional QuEChERS salts. Moreover, optimized pH conditions of HCA extracts before purification, for better extraction recoveries. Furthermore, this method was validated in terms of method validation parameters. Lastly, simulation of real braised beef model provided the minimum formation of HCAs by optimizing cooking parameters and precursors in a cooking system. Therefore, this method could be applied simultaneously on braised beef matrix either marketed or home cooked for HCAs analysis.

Assessment of Apple Peel Barrier Effect to Pesticide Permeation Using Franz Diffusion Cell and QuEChERS Method Coupled with GC-MS/MS.

In this study, a new approach to pesticide permeation through the apple peel into the pulp is discussed. The tested compounds can be classified, based on mode of action, as systemic (boscalid, cyprodinil, pirimicarb, propiconazole and tebuconazole) or contact (captan, cypermethrin and fludioxonil) pesticides. The barrier effect was assessed using a Franz flow-type vertical diffusion cell system. A residue analysis was performed using a modified quick, easy, cheap, efficient, rugged and safe (QuEChERS) extraction method coupled to gas chromatography with tandem mass spectrometry (GC-MS/MS). The limits of detection (LODs) ranged between 2.6 µg kg-1 (pirimicarb) and 17 µg kg-1 (captan), with the coefficient of variability (CV) lower than 6%, while recoveries ranged from 85% (boscalid) to 112% (captan) at 0.1 and 1 mg kg-1 spiked levels. The highest peel penetration was observed for pirimicarb, captan and cyprodinil, with cumulative permeations of 90, 19 and 17 µg cm-2, respectively. The total absorption was in the range from 0.32% (tebuconazole) to 32% (pirimicarb). Only cypermethrin was not quantitatively detected in the pulp, and its use can be recommended in crop protection techniques. The obtained results indicate that molecular weight, octanol-water partition coefficient and water solubility are important parameters determining the process of pesticide absorption.

Development and validation of gas chromatography with electron capture detection method using QuEChERS for pesticide residue determination in cucumber.

A modified quick, easy, cheap, efficient, rugged, and safe (QuEChERS) method coupled to gas chromatography with electron capture detection was developed for the simultaneous determination of selected electronegative pesticides, namely, chlorpyrifos-methyl (1), chlorpyrifos (2), quinolphos (3), profenofos (4), myclobutanil (5), ethion (6), fenpropathrin (7), and cypermethrin (8), in vegetables with high water content. The selected compounds and some of their metabolites have even been found in human body fluids. In addition, some of them are known or suspected carcinogens according to the World Health Organization. Extraction and cleanup parameters were optimized; thus, the original QuEChERS method was modified to minimize solvent usage by making the study eco-friendly. The developed method was validated for selectivity, specificity, linearity, precision, and accuracy using SANTE guidelines. Calibration curves showed good linearity (r > 0.99) within the test range. Precision was evaluated by intra- and inter-day experiments with an acceptable range of less than 20.0% of relative standard deviation. Recovery was evaluated at limit of quantification and was found to be in the range of 70-120%, with relative standard deviations lower than 4.21%. The proposed method is applicable for detection and monitoring of selected pesticides in one run not only in fruits and vegetables with high water content but also in samples containing large quantities of pigments/dyes.

Exposomic Analysis of Organic Pollutants in Seminal Plasma and Male Reproductive Parameters

Previous studies of environmental exposures and male reproductive health have typically examined limited sets of exposures in the urine, which may not accurately capture the chemical burden in relevant tissues and do not consider a large range of concurrent exposures. Here, we used a combined targeted and untargeted exposome approach to identify novel associations of environmental pollutants found in seminal plasma, as individual metabolites and co-exposure patterns, with male reproductive parameters. Semen samples were collected from male partners from 100 heterosexual couples undergoing assisted reproductive treatment in Tel Aviv after 2-7 day abstinence. Semen parameters were assessed for sperm concentration, percent motility, and total motile sperm. Using a novel QuEChERS (quick, easy, cheap, efficient, rugged, and safe) extraction method, 118 targeted and 2005 untargeted organic pollutant exposures were measured from seminal plasma using gas chromatography. We used linear regression, principal component pursuit (PCP), and Bayesian Kernel Machine Regression (BKMR) to estimate the associations of organic pollutants with semen parameters. Using an exposome-wide association approach, we found that etriadizole, a common pesticide, was negatively associated with total motile sperm (p&amp;#x3c;0.001), concentration (p=0.002), and percent motility (p=0.04). Using PCP, a machine learning pattern recognition approach, we derived a low-rank matrix with one major principal component. This principal component was primarily loaded by one phthalate (diethyl phthalate) and three PAHs (anthracene, pyrene, phenanthrene) and was associated with lower total sperm (p=0.03) and percent motility (p=0.05). BKMR results confirmed that as an overall mixture, these four pollutants were negatively associated with percent motility, although anthracene was not important to the mixture effect. Seminal plasma levels of etridiazole, diethyl phthalate, and polycyclic aromatic hydrocarbons (PAHs) are negatively associated with semen parameters. Future exposomic investigations using seminal plasma are warranted. Keywords: exposomics; exposome; seminal plasma; reproduction; reproductive health; semen; sperm; pesticide, etridiazole, phthalates, PAH

Improvement of the QuEChERS method coupled with GC–MS/MS for the determination of pesticide residues in fresh fruit and vegetables

An enhanced methodology for the determination of 31 currently used pesticides (13 insecticides including 7 acaricides, 17 fungicides and 1 herbicide) in food samples was proposed to meet the increasingly stringent legal requirements concerning the maximum pesticide residue limits (MRLs). The procedure involves a modified quick, easy, cheap, efficient, rugged and safe (QuEChERS) method coupled to gas chromatography with tandem mass spectrometry (GC–MS/MS). In order to obtain lower limits of quantification (LOQs), an additional extract preconcentration step prior to their purification was introduced. Retention times of analytes were corrected using the Automatic Adjustment of Retention Time (AART) program, which further improved the efficiency and peak identification after changing the sample matrices. The methodology was validated in accordance with the EU ‘SANTE’ guide and the obtained LOQs were in the range of 0.63 µg kg−1 (fenazaquin) – 39 µg kg−1 (imazalil), with the coefficient of variability (CV) lower than 6 %. The recoveries were in the range of 82 % (etofenprox) – 112 % (captan) at two different spiked levels. The validated procedure has been successfully applied to the analysis of various fruit and vegetable samples with high water content. The MRLs were exceeded for captan (in cucumbers and Ligol apples), dimethoate (in courgettes), lambda-cyhalothrin (in parsley roots) and linuron (in carrots), while the rest of the samples do not pose a health risk.

O-247 Seminal Plasma Exposomics and Male Reproductive Parameters

Abstract Study question What novel environmental exposures found in seminal plasma, as individual metabolites and concurrent exposure patterns, are associated with poor male reproductive parameters? Summary answer Seminal plasma levels of etridiazole, diethyl phthalate, and polycyclic aromatic hydrocarbons (PAHs) are negatively associated with semen parameters. What is known already Numerous environmental exposures have been linked to poor male reproductive markers, but they have typically examined only a limited set of exposures in the urine, which may not be accurate representation of the chemical burden in tissue and do not holistically consider a large range of potential concurrent exposures. Study design, size, duration This cross-sectional study included 100 heterosexual couples undergoing assisted reproductive treatment at a Tertiary University Affiliated Medical Center. Semen samples were collected and fractionated to separate sperm (outcome measurement) and seminal plasma (exposomics analysis). Participants/materials, setting, methods Semen parameters were assessed for sperm concentration (millions/mL), percent motility, and total motile sperm (millions/mL). Using a novel QuEChERS (quick, easy, cheap, efficient, rugged, and safe) based extraction method, targeted and untargeted organic pollutant exposures were measured from 500uL of seminal plasma using a Thermo Q Exactive Orbitrap mass spectrometer. We used linear regression, principal component pursuit (PCP), and Bayesian Kernel Machine Regression (BKMR) to estimate the associations of organic pollutants with semen parameters. Main results and the role of chance We identified 118 known chemicals in seminal plasma from the targeted panel of organic pollutants. Using an exposome-wide association approach, we modeled each exposure with the outcome individually and found that etriadizole, a common pesticide, was negatively associated with total motile sperm (p &amp;lt; 0.001), concentration (p = 0.002), and percent motility (p = 0.04). Using PCP, a machine learning pattern recognition approach, we derived a low-rank matrix with one major principal component. This principal component was primarily loaded by one phthalate (diethyl phthalate) and three PAHs (anthracene, pyrene, phenanthrene) and was associated with lower total sperm (p = 0.03) and percent motility (p = 0.05) in linear regression models. BKMR results confirmed that as an overall mixture, these four pollutants were negatively associated with percent motility, although anthracene was not an important component of the mixture effect. Furthermore, BKMR models showed that other PAHs did not confound or modify the impact of diethyl phthalate, pyrene, and phenanthrene. Limitations, reasons for caution Our sample only included 100 men and larger studies are necessary to confirm the associations identified by this investigation. Furthermore, this current analysis only included a limited number of targeted chemicals and future studies should examine untargeted features as well. Wider implications of the findings To our knowledge, our study is the first to assess a large set of seminal plasma exposures and their relation to semen parameters. Although the biological mechanism(s) underlying the observed associations are unknown, we identified novel associations. Thus, future investigations using broad exposomic approaches in seminal plasma is warranted. Trial registration number PGA 2102 Environmental Health Fund Israel

Occurrence and seasonal variation of several endocrine disruptor compounds (pesticides, bisphenols, musks and UV-filters) in water and sediments from the estuaries of Tagus and Douro Rivers (NE Atlantic Ocean coast)

Exposure of aquatic environments to emerging contaminants is a global issue, special relevant in many estuaries due to impacts from anthropogenic activity. The aim of this work was to evaluate thirty-seven endocrine disruptor chemicals (EDCs) from four different classes (pesticides, bisphenols, polycyclic musks and UV-filters) in water and sediment samples collected during one-year in the estuaries of Tagus and Douro Rivers located into the NE Atlantic Ocean coast. EDCs analysis was achieved afterward validation of a gas-chromatography mass spectrometry (GC–MS) method using Dispersive Liquid-Liquid Microextraction (DLLME) as extraction procedure for water samples, and Quick, Easy, Cheap, Efficient, Rugged and Safe (QuEChERS) combined with DLLME for sediments. Tagus estuary presented higher levels of contamination with pesticide residues and bisphenols (BPs) than the Douro estuary in both water and sediment samples. Contrariwise, levels and frequency of polycyclic musks (PCMs) and UV-filters (UVF) were slightly higher in Douro estuary. Levels of pesticide residues in both sediment and water samples, and levels of PCMs and UVF in water samples were higher in warmer seasons (summer and spring) than in colder ones (winter and autumn). The opposite was found in what respect levels of BPs in water and sediment samples, and PCMs and UVF levels in sediment samples. Although the levels found for each contaminant are low, usually in the order of a few ng/mL(g), the presence of a high number of toxic compounds is a source of concern and requires constant monitoring.

Method Development and Validation of Gas Chromatography Methods using Nitrogen Phosphorus Detector (GC-NPD) and Isotope Dilution Triple Quadrupole Mass Spectrometry (GC-IDMS/MS) for the Determination of Chlorpyrifos in Mango

Pesticides residue determination in fruits like chlorpyrifos is important due to its health effects on humans. Thus, there is a need for sensitive and accurate methods for better quantification. In this study, the performance of two gas chromatographic detection methods, nitrogen phosphorus detector (GC-NPD) and isotope dilution triple quadrupole mass spectrometer (GC-IDMS/MS), for the determination of chlorpyrifos in mango was evaluated to be used for the development of candidate reference material. Other than liquid-liquid extraction (LLE), Quick, Easy, Cheap, Efficient, Rugged and Safe (QuEChERS) sample extraction and dispersive solid phase extraction (dSPE) clean-up procedures were optimized to extract chlorpyrifos from the sample matrix. Comprehensive method validations were performed in GC-NPD and GC-IDMS/MS with HP-5 capillary column to establish linearity, the limit of detection (LOD), the limit of quantification (LOQ), accuracy, repeatability, and intermediate precision using freeze-dried mango samples. The LOD and LOQ were 2.35 and 3.47 µg kg-1 for GC-NPD, and 1.23 and 1.85 µg kg-1 for GC-IDMS/MS, respectively. Matrix-matched calibration curves showed excellent linearity of r2=0.999 for both GC-NPD and GC-IDMS/MS protocols. Acceptable repeatability was obtained for three spike concentrations of 10, 30, and 60 µg kg-1 (n=10) and intermediate precision for 0.5-, 1- and 3-months in the same three-spike concentrations (n=3) expressed as relative standard deviation (RSD) ranging from 0.34-5.61 % for GC-NPD and 0.46-4.22 % for GC-IDMS/MS. Satisfactory mean recoveries (n=10) were achieved: 88.48-109.81% in GC-NPD and 97.61-108.40% in GC-IDMS/MS. GC-IDMS/MS and GC-NPD methods were fit for the purpose of quantifying chlorpyrifos in Philippine mango accurately with the use of isotope dilution technique and traceability to international standards by the application of gravimetric sample preparation.

A miniaturized method for fast, simple, and sensitive pesticide analysis in soils

PurposeOrganochlorine pesticides (OCPs) like lindane and DDT have been used extensively after World War II until the 1990s. Still, residues of these pesticides can be found in agricultural soils all over the world, especially in developing countries. Often, they occur in extensive areas and elevated concentrations so that food safety is jeopardized. Hence, simple, cheap, and fast analytical methods are needed for a straight-forward assessment of risks. A miniaturized solid–liquid extraction combined with solid-phase microextraction (SPME) based on a proven ISO method is presented.MethodsThe performance of the method is evaluated by extracting three different soils which were spiked with HCH and DDT congeners, and trifluralin, and aged for 35 days. The results are compared with those of a modified quick, easy, cheap, efficient, rugged, and safe (QuEChERS) method. For further validation, both methods are applied to three environmental soil samples.ResultsValidation results show limits of detection and quantification as well as recovery rates in good agreement with standard requirements. The new method was found to be quicker than QuEChERS, which requires time-consuming preparation of reagents.ConclusionMerits include low time and sample volume requirements (0.5 g) and the possibility to extract many samples simultaneously, which allows the screening of large sample sizes to determine the pollution status of whole landscape regions. However, access to an automated SPME apparatus is assumed. The authors can recommend this method as a cheap and fast alternative where SPME is available.

Determination of Four Priority Polycyclic Aromatic Hydrocarbons in Food Samples by Gas Chromatography – Mass Spectrometry (GC-MS) after Vortex Assisted Dispersive Liquid-Liquid Microextraction (DLLME)

Dispersive liquid-liquid microextraction (DLLME) is a useful preconcentration technique but its direct application is limited to aqueous samples. Two pretreatment methods for solid samples, QuEChERS (quick easy cheap efficient rugged and safe) and a standard method, were used to isolate four polycyclic aromatic hydrocarbons (PAHs) from the sample matrix. However, since these methods result in analyte dilution, DLLME was used to augment them by concentrating the analytes from 8.0 mL of sample into 150 µL of 1,2-dichloroethane. Under the optimum conditions, the instrumental detection limit was enhanced by approximately 100-fold for chrysene, benzo[a]pyrene, benz[a]anthracene, and benzo[k]fluoranthene with corresponding detection limits of 29, 29, 30, and 28 ng/L, respectively. The precision of the method based on inter-analyst and inter-day analysis yielded relative standard deviations less than 9.0 and 4.0%, respectively. The optimized method was applied to snail samples spiked at 5.0, 10, 20, and 50 ng/g and the recoveries were nearly 100%. Matrix matched standards were also used to determine the recoveries; the results did not vary significantly from the direct calibration recoveries.

Application of a streamlined LC-MS/MS methodology for the determination of atropine and scopolamine in cereals from Asian and African countries

ABSTRACT Tropane alkaloids are toxic secondary metabolites produced by a wide variety of plants that can be present in edible materials or animal feed. Several human poisoning cases through consumption of cereals were reported over the last years and highlighted the need for reliable and robust analytical methodologies for safety control. To rationalize analyses in high-throughput laboratory environments dealing with shorter and shorter turn-around-around time, the scope of our multi mycotoxins method was extended to the analysis of two regulated tropane alkaloids, namely atropine and scopolamine. Extraction procedure is based on the QuEChERS (Quick, Easy, Cheap, Efficient, Rugged, and Safe) approach followed by liquid chromatography tandem mass spectrometry (LC-MS/MS) detection. Quantification is performed by the isotopic dilution approach using labelled isotopomers as internal standard. The procedure was validated at two fortification levels (0.5 µg/kg and 10 µg/kg) on different cereal-based products according to the European SANTE/12682/2019 document and performance parameters such as precision (RSD(r) ≤ 6%, RSD(iR) ≤ 6%) and recovery (82–114%) fulfilled its requirements. The limit of quantification (0.5 µg/kg) is low enough to ensure compliance with existing regulations. The method was further applied on 95 cereals and cereal-based products collected from Asian and African countries. All samples were found free of the two targeted TAs, with the exception of a rice-based product in which both atropine and scopolamine were quantified at 9.6 µg/kg and 2.6 µg/kg, respectively. A total of 29 cereals samples, shown to be free of both atropine and scopolamine were also analysed for mycotoxins. Aflatoxins, fumonisins, and deoxynivalenol were sporadically detected at levels below the maximum levels defined by the European Union legislation often considered as the most stringent regulation.

Determination and uptake of abamectin and difenoconazole in the stingless bee Melipona scutellaris Latreille, 1811 via oral and topic acute exposure

Bees are considered as important providers of ecosystem services, acting via pollination process in crops and native plants, and contributing significantly to the maintenance of biodiversity. However, the decrease of bee's population has been observed worldwide and besides other factors, this collapse is also related to the extensive use of pesticides. In this sense, studies involving the assessment of adverse effects and the uptake of pesticides by bees are of great concern. This work presents an analytical method for the determination of the insecticide abamectin and the fungicide difenoconazole in the stingless bee Melipona scutellaris exposed via oral and topic to endpoints concentrations of active ingredients (a.i.) alone and in commercial formulations and the discussion about its mortality and uptake. For this purpose, QuEChERS (Quick, Easy, Cheap, Efficient, Rugged and Safe) acetate modified method was used for extraction and pesticides were determined by LC-MS/MS. The validation parameters have included: a linear range between 0.01 and 1.00 μg mL−1; and LOD and LOQ of 0.038 and 0.076 μg g−1 for abamectin and difenoconazole, respectively. The uptake of tested pesticides via oral and topic was verified by the accumulation in adult forager bees, mainly when the commercial product was tested. Mortality was observed to be higher in oral exposure than in topic tests for both pesticides. For abamectin in a commercial formulation (a.i.) no differences were observed for oral or topic exposure. On the other hand, for difenoconazole, topic exposure had demonstrated higher accumulation in bees, according to the increase of received dose. Through the results, uptake and the possible consequences of bioaccumulated pesticides are also discussed and can contribute to the knowledge about the risks involving the exposure of bees to these compounds.

Determination of fenazaquin in water and tomato matrices by GC-MS after a combined QuEChERS and switchable solvent liquid phase microextraction

This study presents the use of Quick Easy Cheap Efficient Rugged and Safe (QuEChERS) as an effective sample cleaning procedure and switchable solvent liquid phase microextraction (SS-LPME) as a preconcentration tool for the determination of fenazaquin by gas chromatography mass spectrometry (GC-MS) at ultratrace levels. After a thorough optimization process, 0.50mL of switchable solvent, 1.5mL of 1.0M sodium hydroxide, and 15s of vortexing were determined as optimum conditions of the SS-LPME method. The limit of detection (LOD) and limit of quantitation (LOQ) determined using the optimum method (SS-LPME/GC-MS) were 0.05 and 0.18ng/mL, respectively. Compared with direct GC-MS determination of fenazaquin, the optimum method yielded about 800-fold enhancement in detection power of GC-MS. The method was applied to lake, irrigation canal, well, and wastewater samples. In order to test the method's applicability on fresh tomato samples, a QuEChERS method was used before applying the SS-LPME method. Matrix-matched calibration standards were used to enhance the accuracy of fenazaquin quantification in spiked tomato samples to obtain recovery results close to 100%.

Multiple Mycotoxins Determination in Food by LC-MS/MS: An International Collaborative Study.

An intercollaborative study was organized to evaluate the performance characteristics of a liquid chromatography tandem mass spectrometry procedure for the simultaneous determination of 12 mycotoxins in food, which were ochratoxin A, aflatoxins B1, B2, G1, G2, and M1, deoxynivalenol, zearalenone, fumonisins B1 and B2, and T-2 and HT-2 toxins. The method combined the simplicity of the QuEChERS (Quick, Easy, Cheap, Efficient, Rugged and Safe) approach with the efficiency of immunoaffinity column cleanup (the step used to enhance sensitivity and sample cleanup for some matrices only). Twenty-three entities were enrolled and were European reference laboratories for mycotoxin analysis, U.S. and European service laboratories, and Nestlé laboratories. Each participant analyzed 28 incurred and/or spiked blind samples composed of spices, nuts, milk powder, dried fruits, cereals, and baby food using the protocol given. Method performances were assessed according to ISO 5725-2. Relative standard deviations of repeatability and reproducibility and trueness values for each of the 115 mycotoxin/sample combinations ranged from 5% to 23%, 7% to 26%, and 85% to 129%, respectively, in line with requirements defined in EC 401/2006. The overall set of data gathered demonstrated that the method offered a unique platform to ensure compliance with EC 1881/2006 and EC 165/2013 regulations setting maximum limits for mycotoxins in food samples, even at low regulated levels for foods intended for infants and young children. The method was applicable regardless of the food, the regulated mycotoxin, and the concentration level, and thus is an excellent candidate for future standardization.

QuEChERS-based gas chromatography-electron capture/flame photometric detection method for multi-pesticide residues analysis in Andrographis paniculata: a popular Indian medicinal herb

ABSTRACT Andrographis paniculata (kalmegh) is a medicinal plant consumed at ton scale worldwide. This herb has a high demand both in traditional ayurvedic formulations and in the pharmaceutical industry. Owing to the continuous global demand for pharmaceutical applications, quality of cultivated kalmegh is very important and the presence of pesticide residues may pose serious restrictions by various national/international regulatory bodies for consumer safety. The European pharmacopoeia, require validated methods to determine the pesticide residues in each specific medicinal plant. In order to achieve such requirements, a modified quick, easy, cheap, efficient, rugged and safe (QuEChERS) method coupled with gas chromatography with electron capture detector or flame photometric detection (GC–ECD/FPD) was developed for the determination of the multiclass pesticide residues of 12 organochlorines (OCs), 8 organophosphates (OPs), 6 synthetic pyrethroids (SPs) insecticides, 5 herbicides, and 3 fungicides in kalmegh. Initially, pesticides were extracted with acetonitrile and then, the extracts were purified by dispersive solid-phase extraction clean-up. The developed method showed good linearity for all pesticides with high values of correlation coefficients (0.973–0.997) coupled with low limits of detection (LOD) and quantification (LOQ) values ranging from 0.001–0.01 µg/mL and 0.01–0.075 µg/g, respectively. Matrix effects were also investigated and matrix-matched calibration curves were used for all studies. Mean recoveries (60.8–111.8%, with RSD 8.1%) were within the international acceptable limits (70–120%) along with uncertainty analysis ranging from 7.69 to 21.15%. The validated established method was effectively employed for determining the pesticide residues in real field samples and can be extended for commercial and regulatory residue analysis.

Hmim]PF6 enhanced the extraction of polycyclic aromatic hydrocarbons from soil with the QuEChERS method

To detect, identify, and quantify the polycyclic aromatic hydrocarbons (PAHs) released into the environment, the PAHs need to be isolated from the soil matrix. In this work, a modified quick, easy, cheap, efficient, rugged and safe (QuEChERS) method with ionic liquid was combined with liquid chromatography to identify 16 selected PAHs in soil. Ionic liquid 1-hexyl-3-methylimidazolium hexafluorophosphate ([Hmim]PF6) was applied as an extractant component to enhance the process. The [Hmim]PF6 content in acetonitrile (ACN) was optimized. The [Hmim]PF6 modified QuEChERS method has the advantages defined by its name and a similar recovery to other extraction methods reported in the literature. Adding [Hmim]PF6 may eliminate the co-extract proportion and achieve a more effective extraction. Compared with ACN alone, the matrix effect (ME) of ACN containing 5% [Hmim]PF6 was reduced by approximately 35%. Additionally, the ME of using ACN containing [Hmim]PF6 without a clean-up procedure was similar to that of using ACN followed by a clean-up procedure. The recoveries of the QuEChERS method implemented with [Hmim]PF6 ranged from 75.19% to 100.98%. The limits of detection (LOD) and limits of quantification (LOQ) ranged from 0.86 to 4.51 µg/kg and from 2.87 to 15.13 µg/kg, respectively.

Determination of Selected Priority Pesticides in High Water Fruits and Vegetables by Modified QuEChERS and GC-ECD with GC-MS/MS Confirmation.

A modified quick, easy, cheap, efficient, rugged and safe (QuEChERS) method coupled to gas chromatography with electron capture detector (GC-ECD) was developed for simultaneous determination of selected electronegative pesticides in fruits and vegetables with high water content. The chosen compounds are commonly detected in fruit and vegetable crops, and some of their metabolites have even been found in human urine. In addition, some of them are known or suspected carcinogens according to the International Agency for Research of Cancer. Extraction and clean up parameters were optimized, thus the original QuEChERS method was modified to decrease solvent usage, in accordance with ‘green chemistry’ principles. The proposed methodology was validated in terms of selectivity, specificity, linearity, precision and accuracy. The obtained limits of detection (LODs) for all investigated pesticides ranged from 5.6 µg·kg−1 to 15 µg·kg−1 and limits of quantification (LOQs) from 17 µg·kg−1 to 45 µg·kg−1. The obtained data demonstrated the good reproducibility and stability of the procedure in the tested concentration range up to 10 mg·kg−1, with relative standard deviations (RSDs) lower than 10%. Recoveries for spiked pear samples at LOQ level for each pesticide were from 90% to 107% with RSDs lower than 9.6%. The suitability of the developed procedure was tested on various fruit and vegetable samples available on the market at different seasons. The proposed methodology is applicable for detection and monitoring of selected pesticides not only in fruits and vegetables with high water content, but also in samples containing large amounts of pigments and dyes.

Validation of a modified QuEChERS method for the analysis of organochlorine pesticides in fatty biological tissues using two-dimensional gas chromatography

The monitoring of organic contaminants in the environment has gained tremendous traction in recent times, however, little attention has focused on the development of appropriate methods for the analysis of biological tissues from key sentinel species. In this study, a rapid, low-cost method is presented for the analysis of organochlorine pesticides (OCPs) in fatty biological tissues using a modified QuEChERS (Quick, Easy, Cheap, Efficient, Rugged and Safe) approach. The adapted extraction procedure is tested on biological samples of varying fat content, including fish muscle tissue and two previously untested matrices; coral and adipose tissue. Residue analyses were conducted by two-dimensional gas chromatography−time-of-flight mass spectrometry (GCxGC-TOF-MS). The method was fully validated through the evaluation of recoveries, limits of detection, linearity and precision. Mean recoveries (n = 3) for all 18 target compounds ranged between 69 and 102% across all matrices, with relative standard deviations (RSD) <10% in most cases. Limits of detection (LOD) ranged from 0.1 to 2.0 ng g−1. The method was successfully applied to the analysis of real samples collected from iSimangaliso Wetland Park World Heritage Site, South Africa.

Fast and environmental-friendly methods for the determination of polybrominated diphenyl ethers and their metabolites in fish tissues and feed

Environmental-friendly, cost-effective and fast methods were developed and validated for the analysis of seven PolyBrominated Diphenyl Ethers (PBDEs) and eight methoxylated PBDEs (MeO-PBDEs) in three distinct seafood matrices (muscle, liver and plasma) and feed using a Quick, Easy, Cheap, Efficient, Rugged and Safe (QuEChERS) extraction approach for solid samples and a Dispersive Liquid-Liquid Microextraction method (DLLME) for plasma. Instrumental analyses were performed with gas chromatography coupled to triple quadrupole mass spectrometry using electron impact source (GC-EI-MS/MS) and negative ion chemical ionization (GC-NICI-MS) to assess BDE-209. Statistical validation showed recoveries for all target substances near 100% with average Relative Standard Deviation (RSD) lower than 9% and recovery standards higher than 65% (average RSD below 20%). Average calculated Method Detection Limits (MDLs) were lower than 65 pg·g−1 wet weight (WW) for muscle, 5.35 ng·g−1 WW for liver, 4.50 ng·g−1 WW for feed, and 0.60 ng·mL−1 for plasma samples. Quality assurance and quality control practices were comprehensively described. Methods scored high in an analytical Eco-scale, thus being classified as “an excellent green analysis”. Finally, real seafood samples collected in local markets and local fishermen were analyzed. Positive samples presented both PBDEs and MeO-PBDEs in safe amounts (0.28–125.80 ng·g−1 WW) for human consumption.

Pesticides residue analysis in yam from selected markets across Ghana and Belgium: an evaluation of the QUECHERS method

BackgroundIn recent years, concerns have been raised in Ghana regarding the use of pesticides in yamproduction to the extent that it is feared that pesticides residues may be found in the yam tuber which isconsumed by many Ghanaians. This present study, therefore, was designed to assess the level of pesticides residues in yam bought from across Ghanaian markets i.e. production for local consumption and from Belgium grocery shops (export production from Ghana) using the Quick, Easy, Cheap, Efficient, Rugged and Safe (QuEChERS) method coupled with LC-MS/MS. A total of 180 yam samples, including 150 from Ghana and 30 from Belgium were collected and pesticides residues were analyzed using a multi-residue method.ResultsA total of 25 pesticides were screened in the yam samples and 11 of them were detected. Theresults indicated that about 46% of the samples contained one or more of the 11 detected pesticides in arange of 0.000014 mg/kg up to 0.0146 mg/kg. The three most detected pesticides in this study were fenpropimorph, cadusafos and fenitrothion, occurring in 179, 171 and 126 samples respectively. All the detected pesticides were below their respective EU maximum residue limits (MRL).ConclusionBy these results, it can be said that, the residues of the monitored pesticides found in yam arevery low and are unlikely to pose a negative human health effect.