Analysis Of Pesticides In Food Research Articles

Validation of a global method for the simultaneous analysis of polar and non-polar pesticides by online extraction and LC-MS/MS

BackgroundMulti-residue methods for pesticide analysis in food are available for many compounds, but polar pesticides are not generally included due to their specific properties, which include high polarity and low molecular weight. Single residue methods are therefore needed for sample preparation, while chromatographic separation often requires derivatization, ion paring, or dedicated methods suitable for polar compounds, mostly ion chromatography and hydrophilic interaction liquid chromatography (HILIC). These challenges affect the important pesticide glyphosate and the related compounds aminomethylphosphonic acid (AMPA) and glufosinate. There are only a few methods including these compounds in large-scale analysis, mostly complex methods based on multidimensional chromatography. ResultsA new method, for the global online extraction and analysis of pesticides in beer was developed and validated. The method exploited an online trapping device, with reversed-phase (RP) and anion exchange properties, that can trap small molecules from liquid samples. The ion exchange mechanism was used to retain the very polar pesticides glyphosate, AMPA, and glufosinate. The hydrophobic properties of the trapping column were also exploited to trap pesticides suitable for multi-residue investigations. The chromatographic separation was optimized by comparison of HILIC and RP C30, which could separate pesticides, including the polar ones, with modulation by the trapping column after proper selection of the mobile phase composition and basic modifier. The validation for beer provided recoveries in the range 71–112 %, with <15 % RSD, and LOD and LOQ values of 0.02–1 and 0.3–3 μg L−1, respectively. The result was competitive with previous methods on polar pesticide analysis in beer. SignificanceThe method was validated for 15 pesticides, over the log Kow range from −4.4 to 4.5, using a methodology with single and fast chromatographic separation under conditions compatible with multi-residue analysis by RP-LC-MS/MS. In the case of beer, for which the method was validated, the sample preparation was also performed online, after simple degassing, and sample dilution.

Analysis of pesticides in food: A review on applications of molecularly imprinted polymer nanoparticles and chromatographic methods

Analysis of pesticides in food: A review on applications of molecularly imprinted polymer nanoparticles and chromatographic methods

Comparison of different fast gas chromatography - mass spectrometry techniques (Cold EI, MS/MS, and HRMS) for the analysis of pyrethroid insecticide residues in food.

In the multiclass, multiresidue analysis of pesticides in food and environmental samples, pyrethroid insecticides are generally more difficult to analyze than other types of analytes. They do not ionize well by electrospray ionization, and although they are suitable for analysis by gas chromatography-mass spectrometry (GC-MS), selectivity using standard electron ionization (EI) in GC-MS is often insufficient because the molecular ion is rarely present. Many pyrethroids tend to have the same fragment ions in MS or high-resolution (HR)MS, and similar ion transitions in tandem MS/MS, leading to difficulties in distinguishing different pyrethroids from each other and chemical interferences in complex matrices. In this study, different forms of fast GC coupled with different types of MS detectors were compared for the analysis of up to 15 pyrethroids in barley extracts as a test case to assess which approach was the most advantageous. The three studied GC-MS techniques consisted of Cold EI using supersonic molecular beams in selected ion monitoring (SIM) mode with a single quadrupole instrument; triple quadrupole MS/MS; and HRMS using an orbital ion trap (orbitrap). A higher flow rate was used in Cold EI, and low pressure (LP) GC was employed in the MS/MS and orbitrap methods, to speed up the GC analyses (<10 min chromatograms in all cases). Each technique had some advantages over the others depending on specific pyrethroid analytes in the matrix. Nontargeted LPGC-orbitrap typically yielded the highest selectivity, but it rarely achieved the needed detectability to quantidentify the residues at 10 ng g-1. Cold EI-SIM and LPGC-MS/MS usually met the needed detection limits and generally achieved similar capabilities for the targeted pyrethroids.

A method for the quantitative analysis of polar anionic pesticides in milk/infant formula, cereals and fruit and vegetables using ion chromatography coupled to tandem mass spectrometry.

Polar pesticides such as anionic or ionisable compounds have always provided a challenge for analytical chemists. Methods of analysis have been developed using a range of techniques including normal phase chromatography, ion-pairing, derivatisation and HILIC or multi-mode chromatography. These work well with some of these compounds but, except for HILIC, all of them have their limitations and none of them cover the range required by legislation. Some of these compounds, glyphosate, chlorate and phosphonic acid, are found regularly in a range of food matrices, and therefore reliable methods of analysis are essential. This study describes an ion chromatography method with tandem mass spectrometry detection which not only covers the full range of compounds required by legislation but also can be expanded to include other anionic or ionisable pesticides and metabolites. These include glyphosate and its metabolites, glufosinate and its metabolites, ethephon and its metabolites as well as fosetyl aluminium, chlorate and perchlorate. The method is fully validated according to the performance criteria from the SANTE guidelines for the analysis of pesticides in food and feed over a wide range of matrices, including milk, infant formula, cereals and fruits and vegetables. Over 300 food samples have analysed as part of our routine monitoring program.

Automated micro-solid-phase extraction clean-up and gas chromatography-tandem mass spectrometry analysis of pesticides in foods extracted with ethyl acetate

Generic extraction methods for the multi-compound pesticide analysis of food have found their solid place in laboratories. Ethyl acetate and acetonitrile extraction methods have been developed as fast and easy to handle standard multi-compound methods, both feature benefits and limitations. The direct injection to gas chromatography can be impaired by a high burden of coextracted matrix, resulting in deterioration of the chromatographic system and matrix effects, requiring frequent maintenance. Therefore, common clean-up methods, such as dispersive solid-phase extraction, freeze-out of fats, or gel permeation chromatography, have been applied in clean-up. Automated clean-up using micro-solid-phase extraction (µSPE) is a recent development with several demonstrated advantages when employed in the analysis of pesticides and other contaminants in foods extracted with acetonitrile, but it has not yet been evaluated in this application using ethyl acetate for extraction. In this study, an automated procedure using µSPE cartridges was developed and established on an x,y,z robotic sampler for the raw extract clean-up and preparation of diluted samples for injection on a GC-MS/MS system. Validation experiments for 212 pesticides, polychlorinated biphenyls, and polycyclic aromatic hydrocarbons in lettuce, avocado, raspberry, paprika, egg, and liver extracts were performed using µSPE with MgSO4, PSA, C18, and CarbonX. The performance in routine operation is briefly discussed.Graphical abstract

Facile ultrasonication-assisted synthesis of Purpald-functionalized silver nanoparticles for the rapid spectrophotometric detection of acetamiprid pesticide in food and environmental samples

In this work, we report a highly sensitive and selective colorimetric assay using purpald functionalized silver nanoparticles (P-AgNPs) as a probe for the detection of acetamiprid pesticide in food and environmental samples using Ultraviolet–visible (UV–Vis) spectrophotometric analysis. Several methods, including Fourier transforms infrared spectroscopy, X-ray diffraction spectroscopy, Transmission electron microscopy, X-ray photoelectron spectroscopy and Dynamic light scattering, were used to characterize the synthesized P-AgNPs. As prepared P-AgNPs were spherical in shape and the average particle size was determined to be 17.69 ± 0.3 nm based on TEM analysis. The surface plasmon resonance (SPR) band for P-AgNPs was observed at 445 nm (Visible spectral region). Interestingly, increased acetamiprid pesticide concentration in the sample solution, shows decreased SPR band absorbance due to aggregation of P-AgNPs by electrostatic repulsion. Results showed an excellent linearity range 2.49 to 82.06 µM and the lowest detection limit was 36 nM, the present method is applied to detect acetamiprid pesticide in a variety of environmental and food samples, including soil samples, tomato, carrot, bean, cabbage and cucumber samples, as well as tap and drinking water. Results indicate good accuracy and precision. Therefore, the presented method is proven to be a simple, fast, low-cost and efficient method for analysis of pesticides in food and environmental samples.

Solid-Phase Microextraction-Gas Chromatography Analytical Strategies for Pesticide Analysis.

Due to their extensive use and the globalized commerce of agricultural goods, pesticides have become a global concern. Despite the undoubtful advantages of their use in agricultural practices, their misuse is a threat to the environment and human health. Their analysis in environmental samples and in food products continues to gain interest in the analytical chemistry community as they are challenging matrices, and legal concentration limits are particularly low (in the order of ppb). In particular, the use of solid-phase microextraction (SPME) has gained special attention in this field thanks to its potential to minimize the matrix effect, while enriching its concentration, allowing very low limits of detection, and without the need of a large amount of solvents or lengthy procedures. Moreover, its combination with gas chromatography (GC) can be easily automated, making it a very interesting approach for routine analysis. In this review, advances and analytical strategies for the use of SPME coupled with GC are discussed and compared for the analysis of pesticides in food and environmental samples, hopefully encouraging its further development and routine application in this field.

Perspectives on Liquid Chromatography-High-Resolution Mass Spectrometry for Pesticide Screening in Foods.

This perspective discusses the use of liquid chromatography coupled with high-resolution mass spectrometry (LC-HRMS) for multiresidue analysis of pesticides in foods and agricultural commodities. HRMS has the important distinction and advantage of mass-resolving power and, therefore, requires different concepts, experiments, and guidance for screening, identification, and quantitation of pesticides in complex food matrices over triple quadrupole mass spectrometry. HRMS approaches for pesticide screening, including full-scan experiments in conjunction with tandem mass spectrometry (MS/MS) experiments, are described. This approach results in the generation of chromatographic retention times and high-resolution mass spectra with accurate mass measurements that can be used to create compound databases. New data processing tools can create an efficient and optimized screening approach that can speed the analysis and identification of compounds, reduce the need for chemical standards, and harmonize pesticide analytical procedures.

Determination of pesticides in sewage sludge from an agro-food industry using QuEChERS extraction followed by analysis with liquid chromatography-tandem mass spectrometry.

An analytical method was developed and validated for the determination of ten pesticides in sewage sludge coming from an agro-food industry. The method was based on the application of Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) extraction for solid sewage sludge and SPE extraction for sludge aqueous phase, followed by liquid chromatography (LC) coupled to hybrid quadrupole/linear ion trap mass spectrometry (QqLIT-MS). The QuEChERS method was reported 14years ago and nowadays is mainly applied to the analysis of pesticides in food. More recent applications have been reported in other matrices as sewage sludge, but the complexity of the matrix makes necessary the optimization of the cleanup step to improve the efficiency of the analysis. With this aim, several dispersive solid-phase extraction cleanup sorbents were tested, choosing C18+PSA as a d-SPE sorbent. The proposed method was satisfactorily validated for most compounds investigated, showing recoveries higher than 80% in most cases, with the only exception of prochloraz (71%) at low concentration level. Limits of quantification were lower than 40ngl-1 in the aqueous phase and below 40ngg-1 in the solid phase for the majority of the analytes. The method was applied to solid sludge and the sludge aqueous phase coming from an agro-food industry which processes fruits and vegetables. Graphical abstract Application of LC/MS/MS advanced analytical techniques for determination of pesticides contained in sewage sludge.

Dispersive solid-phase extraction using polyaniline-modified zeolite NaY as a new sorbent for multiresidue analysis of pesticides in food and environmental samples

The applicability of polyaniline (PANI)-modified zeolite NaY as a sorbent for multi-class pesticides extraction was investigated. The sorbent had a sorption capacity of 833mgkg−1 sorbent and preconcentration factor of 42 in the mixture of twenty pesticides. The PANI-coated zeolite NaY was successfully created via oxidative polymerization of aniline onto the surface of the zeolite. The sorbent was applied for dispersive solid phase extraction (DSPE) of commonly used pesticides belonging to five different chemical groups, involving carbamate, organophosphate, sulfonylurea, pyrethroid and neonicotinoid. The coupling of DSPE and HPLC-PDA resulted in an efficient method for multiresidue analysis of pesticides. The proposed method gave LODs and LOQs in the ranges of 0.001–1.00mgL−1 and 0.005−2.50mgL−1, respectively. The method was applied for determination of pesticide residues in environmental and food samples including drinking water, pond waters, soils, honey, cabbages, cucumbers, tomatoes and strawberries which were collected in Khon Kaen Province, Thailand. Recoveries of the target pesticides were in the range of 64−128% with RSDs less than 12% using matrix matched calibration for all sample matrices. Eight pesticides were found in fruit and vegetable samples at concentrations of 0.003–0.033mgkg−1 whereas a few compounds in contaminated pond waters have concentrations of 0.046–0.092mgL−1. The occurrence of high concentration of up to 1.26mgkg−1 in the soil samples is noteworthy.

Recent Advances in Analysis of Pesticides in Food and Drink Samples Using LPME Techniques Coupled to GC-MS and LC-MS: a Review.

Food quality and food safety are major challenges affecting agricultural and industrial aspects of production. Many contaminants from different sources contaminate foods and drinks, leading to disastrous health problems like gene mutations and cancer. Previously, many different methods have been used for the analysis of these contaminants. Liquid-liquid extraction (LLE) has been the most well-known conventional technique used, but its limitations are its tediousness, time required, and the use of large quantities of toxic organic solvents. These limitations have led to the search for other, efficient techniques that are more environmentally friendly. Hence, this review highlights recent advances in liquid-phase (single-drop, hollow fiber, and dispersive liquid-liquid) microextraction procedures for food and drink analyses. Such modifications can be justified for solving limitations associated with the traditional LLE method. The objective of this review is to serve as a reference platform for providing effective management tools for solving problems of pollution, clean-up, and control of food quality and safety globally.

Use of ammonium formate in QuEChERS for high-throughput analysis of pesticides in food by fast, low-pressure gas chromatography and liquid chromatography tandem mass spectrometry

The “quick, easy, cheap, effective, rugged, and safe” (QuEChERS) approach to sample preparation is widely applied in pesticide residue analysis, but the use of magnesium sulfate and other nonvolatile compounds for salting out in the method is not ideal for mass spectrometry. In this study, we developed and evaluated three new different versions of the QuEChERS method using more volatile salts (ammonium chloride and ammonium formate and acetate buffers) to induce phase separation and extraction of 43 representative pesticide analytes of different classes. Fast low-pressure gas chromatography tandem mass spectrometry (LPGC-MS/MS) and liquid chromatography (LC)-MS/MS were used for analysis. The QuEChERS AOAC Official Method 2007.01 was also tested for comparison purposes. Of the studied methods, formate buffering using 7.5g of ammonium formate and 15mL of 5% (v/v) formic acid in acetonitrile for the extraction of 15g of sample (5g for wheat grain) provided the best performance and practical considerations. Method validation was carried out with and without the use of dispersive solid-phase extraction for cleanup, and no significant differences were observed for the majority of pesticides. The method was demonstrated in quantitative analysis for GC- and LC-amenable pesticides in 4 representative food matrices (apple, lemon, lettuce, and wheat grain). With the typical exceptions of certain pH-dependent and labile pesticides, 90–110% recoveries and <10% RSD were obtained. Detection limits were mostly <5ng/g, which met the general need to determine pesticide concentrations as low as 10ng/g for monitoring purposes in food applications.

Cleaning up blood samples using a modified “QuEChERS” procedure for the determination of drugs of abuse and benzodiazepines by UPLC–MSMS☆

The “QuEChERS” (quick, easy, cheap, effective, rugged, and safe) dispersive SPE (dSPE) method is an emerging sample preparation technique that is becoming increasingly popular in the area of multi-residue pesticide analysis in food and agricultural products. A simplified QuEChERS extraction method followed by ultra high performance liquid chromatography–tandem mass spectrometry (UHPLC–MS/MS) has been developed for the simultaneous determination of forensically relevant drugs of abuse (opiates including buprenorphine, methadone and fentanyl and analogues, cocaine and metabolites, amphetamines, LSD) and benzodiazepines and analogues (Z-drugs) in 1mL of human whole blood performing a sole extraction. The method was validated showing good repeatability, accuracy and linearity; LODs were 0.5ng/mL for all benzodiazepines tested while for drugs of abuse LODs varied from 0.05 to 2ng/mL. The method showed high throughput capabilities and was applied on various forensic cases for determination of pharmaceuticals and drugs of abuse.

Planar solid phase extraction clean-up and microliter-flow injection analysis–time-of-flight mass spectrometry for multi-residue screening of pesticides in food

For multi-residue analysis of pesticides in food, a sufficient clean-up is essential for avoiding matrix effects in liquid and gas chromatography (LC and GC) analysis coupled to mass spectrometry (MS). In the last two years, high-throughput planar solid phase extraction (HTpSPE) was established as a new clean-up concept for pesticide residue analysis in fruits and vegetables (C. Oellig, W. Schwack, 2011) and tea (C. Oellig, W. Schwack, 2012). HTpSPE results in matrix-free extracts almost free of interferences and matrix effects. In this study, a time-of-flight mass spectrometer (TOFMS) was applied to directly analyze HTpSPE extracts for pesticide residues. This HTpSPE–microliter-flow injection analysis (μL-FIA)–TOFMS approach detects all pesticides at once in a single mass spectrum, without a liquid chromatographic separation step. Complete sample information was obtained after the injection of the cleaned extract within a single peak. Recovery studies for seven representative pesticides in four different matrices (apples, red grapes, cucumbers, tomatoes) provided mean recoveries of 86–116% with relative standard deviations of 1.3–10% (n=5) using the mass signal intensities under the entire sample peak. Comparing the mass spectra of sample peaks from spiked extracts and solvent standards indicated the efficiency of HTpSPE clean-up. A pesticide database search detected all spiked pesticides with a low incidence of false-positives. HTpSPE of one sample required a few minutes, and numerous samples could be cleaned in parallel at minimal cost with low sample and solvent consumption. The μL-FIA–TOFMS screening then needed an additional 6min per sample. The novel screening approach was successfully applied to QuEChERS extracts of several real samples, and the pesticides identified by HTpSPE–μL-FIA–TOFMS were identical to the pesticides detected by common target LC–MS/MS analyses. The high degree of concordantly identified pesticides by the new developed HTpSPE–μL-FIA–TOFMS approach and target LC–MS/MS demonstrates the applicability as a routine screening method.

Planar solid phase extraction clean-up for pesticide residue analysis in tea by liquid chromatography–mass spectrometry

Efficient clean-up is indispensable for preventing matrix effects in multi-residue analysis of pesticides in food by liquid and gas chromatography (LC and GC) coupled to mass spectrometry (MS). High-throughput planar solid phase extraction (HTpSPE) was recently introduced as a new clean-up concept in residue analysis of pesticides in fruit and vegetables (C. Oellig, W. Schwack, 2011 [45]). Thin-layer chromatography (TLC) was used to completely separate pesticides from matrix compounds and to focus them into a sharp zone, followed by extraction of the target zone by the TLC–MS interface. As rather challenging matrices, tea samples were chosen in this study. Besides chlorophylls and polyphenols, high amount of caffeine is co-extracted resulting in strong matrix effects both in LC–MS and GC–MS. The former HTpSPE procedure was adapted to initial extracts of green and black tea resulting in colorless extracts nearly free of matrix effects and interferences, as shown for seven chemically representative pesticides (acetamiprid, penconazole, azoxystrobin, chlorpyrifos, pirimicarb, fenarimol, and mepanipyrim). LC–MS/MS calibration curves obtained in the range of 0.002–0.5mg/kg from matrix-matched standards and solvent standards were nearly identical and demonstrated the effectiveness of clean-up by HTpSPE. Mean recoveries determined by LC–MS/MS against solvent standards at spiking levels of 0.01 and 0.1mg/kg ranged between 72 and 114% with relative standard deviations (RSDs) of 0.7–4.7% (n=4), while LC–MS measurements of tea samples spiked at 1mg/kg provided recoveries of 81–104% with RSDs of 1.2–4.9% (n=6). Using LC–MS/MS, the method showed high sensitivity with signal-to-noise ratios >10 for concentrations below 0.002mg/kg. HTpSPE of one sample was done in a few minutes, while numerous samples were cleaned in parallel at minimal costs with very low sample and solvent consumption.

GC/MSにおけるマトリックス効果原因物質の探索およびその検証

GC/MSにおけるマトリックス効果原因物質の探索およびその検証

Planar solid phase extraction—A new clean-up concept in multi-residue analysis of pesticides by liquid chromatography–mass spectrometry

Efficient clean-up is indispensable for preventing matrix effects in multi-residue analysis of pesticides in food by liquid and gas chromatography coupled to mass spectrometry. As a completely new approach, highly automated planar chromatographic tools were applied for powerful clean-up, called high-throughput planar solid phase extraction (HTpSPE). Thin-layer chromatography (TLC) was used to completely separate pesticides from matrix compounds and to focus them into a sharp zone, followed by extraction of the target zone by the TLC–MS interface. HTpSPE resulted in extracts nearly free of interference and free of matrix effects, as shown for seven chemically representative pesticides in four different matrices (apples, cucumbers, red grapes, tomatoes). Regarding the clean-up step, quantification by LC–MS provided mean recovery (against solvent standards) of 90–104% with relative standard deviations of 0.3–4.1% ( n = 5) for two spiking levels of 0.1 and 0.5 mg/kg. Clean-up of one sample was completed in a manner of minutes, while running numerous samples in parallel at reduced costs, with very low sample and solvent volumes.

Determination of 195 pesticide residues in Chinese herbs by gas chromatography–mass spectrometry using analyte protectants

The phenomenon known as “matrix-induced enhancement effect” is not only observed in the analysis of pesticides in food, but also in Chinese herbs. Several approaches have been proposed to overcome the matrix-induced effect, but each method has serious limitations. Compared with standard calibration methods, the procedure with adding analyte protectants offers a more convenient and effective route to solve the problem. In the current study, we have analyzed 195 types of pesticides in Chinese herbs by gas chromatography–mass spectrometry (GC–MS), and the compounds that are susceptible to matrix effect were picked up and confirmed. In addition, several analyte protectants were evaluated and the most effective combination was determined. d-Ribonic acid-γ-lactone (2 mg/ml) and d-sorbitol (1 mg/ml) were shown to be the best analyte protectants for the analysis of most pesticides.

Ultra-performance liquid chromatography–tandem mass spectrometry: A novel challenge in multiresidue pesticide analysis in food

Potential of ultra-performance liquid chromatography (UPLC) separation strategy coupled with tandem (in space) mass spectrometric detection (MS/MS) in multiresidue pesticide analysis was critically assessed. Performance parameters such as number of theoretical plates, height of theoretical plate, peak symmetry and peak capacity were measured/calculated on the basis of data generated by analysis of apple extracts containing 17 (semi)polar pesticides representing various classes of active ingredients of widely used crop protective preparations. Ultra-performance liquid chromatography–tandem mass spectrometry (UPLC–MS/MS) procedure provided improved chromatographic parameters resulting in significantly increased sample throughput including lower solvent consumption and lower limits of quantitation (LOQs) for most of target analytes compared to common method employing conventional high-performance liquid chromatography (HPLC) separation.

Time of flight mass spectrometry applied to the liquid chromatographic analysis of pesticides in water and food

Liquid chromatography coupled to mass spectrometry (LC-MS) is an excellent technique to determine trace levels of polar and thermolabile pesticides and their degradation products in complex matrices. LC-MS can be equipped with several mass analyzers, each of which provides unique features capable to identify, quantify, and resolve ambiguities by selecting appropriate ionization and acquisition parameters. We discuss in this review the use of LC coupled to (quadrupole) time-of-flight mass spectrometry (LC-(Q)ToF-MS) to determine the presence of target and non-target pesticides in water and food. This technique is characterized by operating at a resolving power of 10,000 or more. Therefore, it gives accurate masses for both parent and fragment ions and enables the measurement of the elemental formula of a compound achieving compound identification. In addition, the combination of quadrupole-ToF permits tandem mass spectrometry, provides more structural information, and enhances selectivity. The purpose of this article is to provide an overview on the state of art and applicability of liquid chromatography time-of-flight mass spectrometry (LC-ToF-MS), and liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QToF-MS) for the analysis of pesticides in environmental matrices and food. The performance of such techniques is depicted in terms of accurate mass measurement, fragmentation, and selectivity. The final section is devoted to describing the applicability of LC-(Q)ToF-MS to routine analysis of pesticides in food matrices, indicating those operational conditions and criteria used to screen, quantify, and identify target and "suspected" pesticides and their degradation products in water, fruits, and vegetables. The potential and future trends as well as limitations of LC-(Q)ToF-MS for pesticide monitoring are highlighted.