The utilisation of ion chromatography and tandem mass spectrometry (IC-MS/MS) for the multi-residue simultaneous determination of highly polar anionic pesticides in fruit and vegetables

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.

Determination of highly polar anionic pesticides in beehive products by hydrophilic interaction liquid chromatography coupled to mass spectrometry

The analysis of highly polar pesticides is challenging due to their unique physicochemical properties, requiring specialized chromatographic techniques for their accurate and sensitive detection. Furthermore, the high level of co-extracted polar matrix components that can co-elute with the analytes can interfere with the analysis. Consequently, there is lack of pesticide monitoring data, as the European Food Safety Authority has pointed out. This article explores the overcoming of such difficulties in the analysis of these compounds. Analytical methodologies for the extraction, clean-up, and direct determination of 11 highly polar anionic pesticides, including glyphosate, glufosinate, ethephon, fosetyl-aluminium, and their related metabolites in complex food matrices such as honey and pollen by hydrophilic interaction liquid chromatography coupled to tandem mass spectrometry were successfully developed and validated. Solid-phase extraction and micro-solid-phase extraction employing strong anion exchange (SAX) cartridges were implemented for clean-up. The automation and miniaturization of SAX clean-up for these compounds were achieved for the first time. For method validation, SANTE/11312/2021 guideline was followed. Recoveries were between 70 and 120%, with RSDs below 20%. Limits of quantitation ranged from 0.005 to 0.020 mg kg-1. Linearity was evaluated from 0.002 to 0.200 mg kg-1. Matrix effects were assessed, showing medium to low signal suppression for most compounds. AMPA and glufosinate presented the highest signal suppression, but it was reduced after SAX clean-up. Analysis of real honey and pollen samples revealed the occurrence of the studied compounds in beehive products and showed the applicability of the validated methodologies for routine control of these complex samples.

Real-Time Monitoring of Translocation, Dissipation, and Cumulative Risk of Maleic Hydrazide in Potato Plants and Tubers by Ion Exclusion Chromatography

In this paper, a high-performance ion exclusion chromatographic (ICE) method was developed and applied for monitoring maleic hydrazide (MH) translocation in complex potato plant tissue and tuber matrices. After middle leaf uptake, most MH was trapped and dissipated in the middle leaf, and the rest was transported to other parts mainly through the phloem. Soil absorption significantly reduced the uptake efficiency of the root system, in which MH was partitioned to dissipate in root protoplasts or transfer through the xylem and persisted in the plant. Tuber uptake enabled MH to remain in the flesh and maintain stable levels under storage conditions, but during germination, MH was translocated from the flesh to the growing buds, where it dissipated through the short-day photoperiodic regime. The results demonstrated successful application of the ICE method and provided necessary insights for real-time monitoring of MH translocation behavior to effectively improve potato edible safety.

Non-targeted and suspect screening analysis using ion exchange chromatography-Orbitrap tandem mass spectrometry reveals polar and very mobile xenobiotics in Danish drinking water

Non-targeted and suspect screening analysis is gaining approval across the scientific and regulatory community to monitor the chemical status in the environment and thus environmental quality. These holistic screening analyses provides the means to perform suspect screening and go beyond to discover previously undescribed chemical pollutants in environmental samples. In a case study, we developed and optimized a high-resolution tandem mass spectrometry platform hyphenated with anion exchange chromatography to screen drinking water samples in Denmark. The optimized non-targeted screening method was able to detect anionic and polar compounds and was successfully applied to drinking water from two drinking water facilities. Following a data analysis pipeline optimization, anionic pesticide residues and other environmental contaminants were detected at confidence identification level 1 such as dimethachlor ESA, mecoprop, and dichlorprop in drinking water. In addition to these three substances, it was possible to detect another 1662 compounds, of which 97 were annotated at confidence identification level 2. More research is urgently needed to health risk prioritize the detected substances and to determine their concentrations.

A review on current progress of Raman-based techniques in food safety: From normal Raman spectroscopy to SESORS

Frequently occurrence of food safety incidents has induced global concern over food safety. To ensure food quality and safety, an increasing number of rapid and sensitive analytical methods have been developed for analysis of all kinds of food composition and contaminants. As one of the high-profile analytical techniques, Raman spectroscopy has been widely applied in food analysis with simple, rapid, sensitive, and nondestructive detection performance. Research on Raman techniques is a direction of great interest to many fields, especially in food safety. Hence, it is crucial to gain insight into recent advances on the use of Raman-based techniques in food safety applications. In this review, we introduce Raman techniques from normal Raman spectroscopy to developed ones (e.g., surface enhanced Raman scattering (SERS), spatially offset Raman spectroscopy (SORS), surface-enhanced spatially offset Raman spectroscopy (SESORS)), in view of their history and development, principles, design, and applications. In addition, future challenges and trends of these techniques are discussed regarding to food safety.

Analysis of environmental pollutants using ion chromatography coupled with mass spectrometry: A review

The rise of emerging pollutants in the current environment and requirements of trace analysis in complex substrates pose challenges to modern analytical techniques. Ion chromatography coupled with mass spectrometry (IC-MS) is the preferred tool for analyzing emerging pollutants due to its excellent separation ability for polar and ionic compounds with small molecular weight and high detection sensitivity and selectivity. This paper reviews the progress of sample preparation and ion-exchange IC-MS methods in the analysis of several major categories of environmental polar and ionic pollutants including perchlorate, inorganic and organic phosphorus compounds, metalloids and heavy metals, polar pesticides, and disinfection by-products in past two decades. The comparison of various methods to reduce the influence of matrix effect and improve the accuracy and sensitivity of analysis are emphasized throughout the process from sample preparation to instrumental analysis. Furthermore, the human health risks of these pollutants in the environment with natural concentration levels in different environmental medias are also briefly discussed to raise public attention. Finally, the future challenges of IC-MS for analysis of environmental pollutants are briefly discussed.

Application of a novel hybrid MIL-53(Al)@rice husk for the adsorption of glyphosate in water: Characteristics and mechanism of the process

The development of new materials that have a high capacity to remove pollutants in water-based media is becoming increasingly important because of the serious contamination of water and the negative impact on biodiversity and public health. The presence of glyphosate in water, the most widely used herbicide worldwide, has triggered alerts owing to the collateral effects it may cause on human health. The main objective of the present study was to investigate the potential of the hybrid material MIL-53(Al)@RH for the adsorption of glyphosate in aqueous solution. The material was obtained following the methodology of MIL-53(Al) synthesis in the presence of hydrolyzed rice husk assisted by microwave. Batch adsorption experiments were carried out to evaluate the adsorbent dosage, pH₀ solution effect, contact time, adsorbate concentration, and temperature effect. The results demonstrated that a maximum adsorption capacity of 296.95 mg g^-1, at pH₀ 4 with a ratio of 0.04 g MIL-53(Al)@RH/50 mL of solution, was achieved in 30 min. The Avrami and pseudo-second order models appropriately described the adsorption kinetics and the equilibrium by Langmuir and Sips models. The enthalpy changes (ΔH°) determined propose an endothermic reaction governed by chemisorption, corroborating the kinetic and equilibrium settings. Hydrogen bonds, π*-π interactions, and complexation between the metal centers of MIL-53(Al) and the anionic groups of glyphosate were postulated to be involved as adsorption mechanisms. Finally, for practical application, MIL-53(Al)@RH was packed in a column for a fixed-bed test which revealed that the hybrid can remove glyphosate with an adsorption capacity of 76.304 mg L^-1, utilizing 90% of the bed.

Development of an inexpensive and rapidly preparable enzymatic pencil graphite biosensor for monitoring of glyphosate in waters

Glyphosate (GLY) is the most widely used non-selective broad-spectrum herbicide worldwide under well-reported side effects on the environment and human health. That's why it's necessary to control its presence in the environment. This work describes the development of an affordable, simple, and accurate electrochemical biosensor using a pencil graphite electrode as support, a horseradish peroxidase enzyme immobilized on a polysulfone membrane doped with multi-walled carbon nanotubes. The developed electrochemical sensor was used in the determination of GLY in river and drinking water samples. Cyclic voltammetry and amperometry were used as electrochemical detection techniques for the characterization and analytical application of the developed biosensor. The working mechanism of the biosensor is based on the inhibition of the peroxidase enzyme by GLY. Under optimal experimental conditions, the biosensor showed a linear response in the concentration range of 0.1 to 10 mg L^-1. The limits of detection and quantification are 0.025 ± 0.002 and 0.084 ± 0.007 mg L^-1, respectively, which covers the maximum residual limit established by the EPA for drinking water (0.7 mg L^-1). The proposed biosensor demonstrated high reproducibility, excellent analytical performance, repeatability, and accuracy. The sensor proved to be selective against other pesticides, organic acids, and inorganic salts. Application on real samples showed recovery rates ranging between 98.18 ± 0.11 % and 97.32 ± 0.23 %. The analytical features of the proposed biosensor make it an effective and useful tool for the detection of GLY for environmental analysis.

Direct determination of glyphosate, aminomethylphosphonic acid and glufosinate in food samples with ion chromatography coupled to electrospray ionization tandem mass spectrometry

A fast and reliable method for the direct determination of the herbicide glyphosate, its major degradation product aminomethylphosphonic acid (AMPA) and glufosinate is presented for a variety of food matrices. The Quick Polar Pesticides in food of Plant Origin method (QuPPe-PO-Method) was used for extraction without further preconcentration or clean-up steps involving e.g. solid phase extraction (SPE). The method makes use of a commercially available high performance liquid chromatograph coupled to a tandem mass spectrometer with electrospray ionization (LC-ESI-MS/MS) - as present in many laboratories - equipped with an ion chromatography (IC)-column using an MS-compatible eluent made of 0.8% formic acid in water. Due to the absence of time-consuming clean-up procedures, strong matrix effects (ME) of up to 91% for AMPA in grapefruit can be observed, when comparing its sensitivity to that obtained for solvent-based standards. The limits of detection (LODs) were determined for the sample matrices apple, mushrooms, grapefruit, linseed, red lentils and wheat and they were found to be in the range of 0.09 to 0.8, 0.04 to 1 and 0.2 to 2 µg/kg for glyphosate, AMPA and glufosinate, respectively. For the same matrices the validation was carried out according to SANTE guidelines for different commodity groups by spiking them up prior to extraction to concentrations ranging from 10 to 400 µg/kg for matrices with high water content and from 10 to 800 µg/kg for matrices with low water content. When using solvent-based calibration under the use of isotopically labelled internal standards (ILIS) the recoveries were found to range from 84% to 120% and the relative standard deviations (RSD) range between 1% and 19% for glyphosate, AMPA and glufosinate at all fortification levels for all matrices investigated. Accordingly, the method was successfully introduced in our laboratory with limits of quantification (LOQs) of 10 µg/kg for glyphosate, AMPA and glufosinate in samples from SANTE commodity groups 1, 2, 4a and 5. The reliability and robustness of the method are demonstrated by showing a recovery control chart obtained for glyphosate in randomly selected samples from different commodity groups. Therefore, the samples were spiked up with 10 µg/kg of glyphosate during routine analysis, whereby all recoveries were found to be in the range between 70 and 120%.

Monitoring and Exposure Assessment of Fosetyl Aluminium and Other Highly Polar Pesticide Residues in Sweet Cherry

Cherries are popular fruits due to their health benefits, organoleptic quality, and attractive appearance. Since highly polar pesticides are of low mass and amphoteric character, and are not amenable to traditional multi-residue extraction methods, they are more commonly not included in the pesticide monitoring program. This study aims to determine twelve highly polar pesticide residues in cherry samples intended for export from Turkey. A total of 16,022 cherry samples from 2018−2020 harvests in four production areas of Turkey were analyzed using a modification of the Quick Polar Pesticides method and liquid chromatography-tandem mass spectrometry. The method was validated at two fortification levels (0.01 and 0.05 mg kg−1), and good recoveries (87.4−111.4%) and relative standard deviations (<6%) were achieved for all analytes. The limits of quantification were in the range of 1.08−2.55 μg kg−1. Overall, 28.4% of the analyzed cherry samples were detected with phosphonic acid, calculated as fosetyl aluminium (fosetyl-Al) in amounts up to 77.7 mg kg−1. For 2304 samples (14.4%), the residues exceeded the European Union maximum residue level of 2 mg kg−1. There is no reason to be concerned about long-term exposure to phosphonic acid/fosetyl-Al, and the other highly polar pesticides through the consumption of sweet cherry.

Airborne polar pesticides in rural and mountain sites of North-Eastern Italy: An emerging air quality issue

North-Eastern Italy and in particular Veneto Region, stands out as a major centre of agriculture and viticulture which has rapidly expanded in the last decade with high productivity indexes. In this context, assessing atmospheric pollution caused by crop spraying with pesticides in rural areas and their transport to high-altitude remote sites is crucial to provide a basis for understanding possible impacts on the environment and population health. We aim to improve existing methods with a highly sensitive technique by using high pressure anion exchange chromatography coupled to a triple quadrupole mass spectrometer. Thus, a total of fourteen polar pesticides were determined in aerosol samples collected from August to December 2021 at Roncade (Venetian plain) and Col Margherita Observatory (Dolomites). The observatory was chosen as the background site as it is representative of the surrounding alpine region. Some samples revealed a substantial amount of cyanuric acid mainly at Roncade (mean concentration of 10 ± 10 ng m^-3), glyphosate and fosetyl-aluminium (0.1 ± 0.2 and 0.1 ± 0.1 ng m^-3, respectively). Surprisingly, some pesticides have been also found at Col Margherita, a high mountain background site, with concentrations an order of magnitude lower than at Roncade. This is the first time that fourteen polar pesticides have been assessed in the aerosol phase of the Po' Valley and detected at a high-altitude remote site, and consequently this study provides the first data on their occurrences in Italian aerosols. It represents a basis for the assessment of risks for humans.

Comparison of Ion Chromatography Conductivity Detection (IC-CD) and Ion Chromatography Inductively Coupled Plasma Mass Spectrometry (IC-ICP-MS) for the Determination of Phosphonic Acid in Grapevine Plant Parts, Wine, and Soil

Potassium dihydrogen phosphonate had been allowed as a plant strengthener in organic viticulture in the European Union only until 2013, supporting the control of grapevine downy mildew. Therefore, low or nondetectable levels are a prerequisite for marketing of organic wines and, consequently, validated analytical methods are of major interest. Herein, two methods based on ion chromatography conductivity detection (IC-CD) or ion chromatography inductively coupled plasma mass spectrometry (IC-ICP-MS) for the determination of phosphonic acid (H₃PO₃) from 14 different plant matrices of Vitis vinifera L., wine, and soil were developed, validated, and compared. Extraction recoveries ranged from 95.1 to 99.3%. Limits of quantification (LOQ) ranged in liquid and solid samples from 3.8 to 16.8 μg/kg and 0.08 to 2.41 mg/kg for ICP-MS detection and from 39.9 to 593.7 μg/kg and 3.51 to 58.7 mg/kg for CD, respectively. Data on a current anonymized selection of 100 conventionally and 30 organically produced wines are briefly presented to demonstrate the suitability of the method.

Current Role of Mass Spectrometry in the Determination of Pesticide Residues in Food

The extensive use of pesticides represents a risk to human health. Consequently, legal frameworks have been established to ensure food safety, including control programs for pesticide residues. In this context, the performance of analytical methods acquires special relevance. Such methods are expected to be able to determine the largest number of compounds at trace concentration levels in complex food matrices, which represents a great analytical challenge. Technical advances in mass spectrometry (MS) have led to the development of more efficient analytical methods for the determination of pesticides. This review provides an overview of current analytical strategies applied in pesticide analysis, with a special focus on MS methods. Current targeted MS methods allow the simultaneous determination of hundreds of pesticides, whereas non-targeted MS methods are now applicable to the identification of pesticide metabolites and transformation products. New trends in pesticide analysis are also presented, including approaches for the simultaneous determination of pesticide residues and other food contaminants (i.e., mega-methods), or the recent application of techniques such as ion mobility–mass spectrometry (IM–MS) for this purpose.

Determination and dietary intake risk assessment of 35 pesticide residues in cowpea (Vigna unguiculata [L.] Walp) from Hainan province, China

The presence of pesticide residues in cowpea raises serious health concerns. In this study, a novel, sensitive, high-performance method was developed to simultaneously analyze the residues of 35 pesticides in cowpea samples from growing areas in the Hainan province of China, from November 2018 to June 2021. The method employs modified QuEChERS sample pretreatment coupled with gas chromatography-tandem mass spectrometry. The limits of quantification of the 35 pesticides in the cowpea matrix ranged from 1.0 to 8.0 μg/kg. Twenty-seven of the 35 pesticides were detected, twelve of which are banned for use on legumes in China. Residues for ten pesticides in 17.1% of the samples exceeded their MRLs, with the highest exceedance of 380% observed in difenoconazole. Moreover, 80.8% of the samples contained one or more pesticide residues, with the most frequently detected pesticide being chlorfenapyr with a detection rate of 46.3%. In addition, the pesticide triazophos was detected through different years and regions. Notably, the chronic dietary exposure risk (%ADI) of the detected pesticides, evaluated from the national estimated acceptable daily intake, was lower than 100% in Chinese people of different age groups.

Anion Exchange Chromatography Coupled to Electrospray-Mass Spectrometry: An Efficient Tool for Food, Environment, and Biological Analysis

For over 50 years, ion chromatography has been demonstrated to be a successful technique used to quantify a wide range of ions and ionizable compounds, either organic or inorganic, in various matrices using conductimetric or electrochemical detection. It was only since 1996 that ion chromatography was coupled to electrospray-mass spectrometry, opening the field to new applications in complex matrices and the detection of compounds at trace levels. This review covers the recent developments of ion exchange chromatography and mass spectrometry. It focuses on the choice of mobile phases, column geometry, suppressors, make-up solvents and type of ionization sources reported in the literature. A brief overview of a large range of applications in food analysis, environmental analysis and bioanalysis is presented, and performances are discussed.

Rapid determination of lambda-cyhalothrin residues on Chinese cabbage based on MIR spectroscopy and a Gustafson–Kessel noise clustering algorithm

Pesticide residues exceeding the standard in Chinese cabbage is harmful to human health. In order to quickly, non-destructively and effectively qualitatively analyze lambda-cyhalothrin residues on Chinese cabbage, a method involving a Gustafson–Kessel noise clustering (GKNC) algorithm was proposed to cluster the mid-infrared (MIR) spectra. A total of 120 Chinese cabbage samples with three different lambda-cyhalothrin residue levels (no lambda-cyhalothrin, and cases where the ratios of lambda-cyhalothrin and water were 1 : 500 and 1 : 100) were scanned using an Agilent Cary 630 FTIR spectrometer for collecting the MIR spectra. Next, multiple scatter correction (MSC) was employed to eliminate the effects of light scattering. Furthermore, principal component analysis (PCA) and linear discriminant analysis (LDA) were utilized to reduce the dimensionality and extract the feature information from the MIR spectra. Finally, fuzzy c-means (FCM) clustering, Gustafson–Kessel (GK) clustering, noise clustering (NC) and the GKNC algorithm were applied to cluster the MIR spectral data, respectively. The experimental results showed that the GKNC algorithm gave the best classification performance compared against the other three fuzzy clustering algorithms, and its highest clustering accuracy reached 93.3%. Therefore, the GKNC algorithm coupled with MIR spectroscopy is an effective method for detecting lambda-cyhalothrin residues on Chinese cabbage.

Pesticide residues exceeding the standard in Chinese cabbage is harmful to human health.

Separation of fosetyl and phosphonic acid in food matrices with mixed-mode HPLC column coupled with tandem mass spectrometric detection and method application to other highly polar pesticides

The aluminum salt of fosetyl (tris(ethyl phosphonate)) is an antifungal agrochemical. This paper presents a novel high performance liquid chromatography (HPLC) method for the simultaneous determination of fosetyl and the phosphonic acid, its main metabolite, in food samples. The method is based on an ion-displacement separation performed on the recently released Luna Omega PS C₁₈ mixed-mode HPLC column. Baseline separation of fosetyl and phosphonic acid was feasible. This was achieved by optimizing the mobile phase composition and by introducing ethylenediaminetetraacetate for all matrices in the generally used extraction medium for polar pesticides and the injection solution. The binary mobile phase consisted of 10% (v/v) methanol in water and aqueous formate buffer (pH = 3.5) in gradient elution mode. The main advantages of the method over previous method include the stable retention time and peak resolution without the need for long column priming, conditioning or regeneration. Moreover, the approach was tested with other polar pesticides including glyphosate, glufosinate, and perchlorate and showed fit-for-purpose separation. The method was validated for spinach, cherry, and wheat flour samples, and was successfully applied on oat flour and arugula quality control samples. The results obtained for the five analytes met the requirements set by EU. The limit of quantifications was much lower than the maximum residue limits and ranged from 0.02 to 0.20 mg/kg.

Glyphosate Use, Toxicity and Occurrence in Food

Glyphosate is a systemic, broad-spectrum and post-emergent herbicide. The use of glyphosate has grown in the last decades, and it is currently the most used herbicide worldwide. The rise of glyphosate consumption over the years also brought an increased concern about its possible toxicity and consequences for human health. However, a scientific community consensus does not exist at the present time, and glyphosate’s safety and health consequences are controversial. Since glyphosate is mainly applied in fields and can persist several months in the soil, concerns have been raised about the impact that its presence in food can cause in humans. Therefore, this work aims to review the glyphosate use, toxicity and occurrence in diverse food samples, which, in certain cases, occurs at violative levels. The incidence of glyphosate at levels above those legally allowed and the suspected toxic effects of this compound raise awareness regarding public health.

Quantification of fosetyl-aluminium/phosphonic acid and other highly polar residues in pomegranates using Quick Polar Pesticides method involving liquid chromatography-tandem mass spectrometry measurement

Interest in the quantification of highly polar substances in crops has noticeably increased in the last five years. This study was designed to assess quantification of six polar residues, chlorate, ethephon, fosetly-aluminium (fosetyl-Al), glyphosate, phosphonic acid and perchlorate. A total of 2513 pomegranate samples intended for export from Turkey were analysed using the Quick Polar Pesticides (QuPPe) method. The method was in-house validated with very good performance results. The limits of quantification (LOQs) for residues were much lower than the respective EU Maximum Residue Levels (MRLs). Phosphonic acid was detected in 38.5% of pomegranate samples at quantifiable concentrations, calculated as fosetyl-Al. The concentrations ranged between 0.005 and 12.9 mg kg^-1. The 20% of pomegranate samples showed fosetyl-Al levels above the EU MRL of 2 mg kg^-1. Other polar residues were not detected in any pomegranate samples. This is the first report about highly polar pesticides in pomegranates cultivated in Turkey.

Glyphosate and other highly polar pesticides in fruit, vegetables and honey using ion chromatography coupled with high resolution mass spectrometry: Method validation and its applicability in an official laboratory

An analytical method, using ion chromatography coupled to high resolution mass spectrometry was developed and validated to quantify glyphosate, glufosinate, ethephon, fosetyl aluminium and their related metabolites. This method allows multiresidue analysis of 11 highly polar molecules in a single chromatographic run, without derivatization step, using acidified water with low level of acetonitrile as extraction solvent. Three different matrices that are representative of commodity group were studied and validated: one fruit (grapes), one cereal (wheat) and honey, according to the criteria established by SANTE/12682/2019 taking into account maximum residue limits indicated by Regulation (EC) No. 396/2005, confirming that the procedure was selective, repeatable and robust. Matrix effect was studied and linearity was evaluated comparing analytical response differences between solvent standard solutions and matrix-matched calibration curve. Due to the relevant matrix effect observed, the use of response factor (RF) approach to quantify analytical batch was evaluated, using isotopically labelled internal standardisation. The in-depth study, validation results and several proficiency tests, used to verify procedure performance, demonstrated that the method is fit for purpose to routine analysis in an official laboratory. Moreover, it allows surveillance activities in fruits and vegetables control, as indicated by European Community, furthermore monitoring presence of polar pesticides, at low level, in some particular food as honey that could become environmental pollution indicator.

Analytical methods to analyze pesticides and herbicides

This paper reviews studies published in 2019, in the area of analytical techniques for determination of pesticides and herbicides. It should be noted that some of the reports summarized in this review are not directly related to but could potentially be used for water environment studies. Based on different methods, the literatures are organized into six sections, namely extraction methods, electrochemical techniques, spectrophotometric techniques, chemiluminescence and fluorescence methods, chromatographic and mass spectrometric techniques, and biochemical assays. PRACTITIONER POINTS: Totally 141 research articles have been summarized. The review is divided into six parts. Chromatographic and mass spectrometric techniques are the most widely used methods.

Selective multiresidue determination of highly polar anionic pesticides in plant-based milk, wine and beer using hydrophilic interaction liquid chromatography combined with tandem mass spectrometry

In this work, an easy and fast procedure for the selective multiresidue determination of 14 highly polar pesticides (including glyphosate, glufosinate, ethephon and fosetyl) and metabolites in beverages is presented. After an initial sample dilution (1:1, v/v), the extract is shaken and centrifuged, further diluted and then injected directly into the LC-MS/MS system, using hydrophilic interaction liquid chromatography (HILIC) and tandem mass spectrometry. No clean-up procedure was needed. The method was validated according to the current European guidelines for pesticide residue analysis in food and feed and linearity, limits of detection and quantification, matrix effects, trueness and precision were assessed. For plant-based milk, wine and beer samples, 10, 11 and 12 analytes, respectively, out of 14 were fully validated at 10 µg kg^-1, the lowest spike level tested. The matrix effect was negative in most of the cases, showing for some compounds, such as HEPA, up to 80% suppression when compared to the response from standards in solvent. The use of isotopically labelled internal standards is required for the optimal quantification, as it compensates for high and varying matrix effects and also for recovery losses during extraction.

Development and Application of a Novel Pluri-Residue Method to Determine Polar Pesticides in Fruits and Vegetables through Liquid Chromatography High Resolution Mass Spectrometry

Nowadays, highly polar pesticides are not included in multiresidue methods due to their physico-chemical characteristics and therefore, specific analytical methodologies are required for their analysis. Laboratories are still looking for a pluri-residue method that encompasses the largest number of polar pesticides. The aim of this work was the simultaneous determination of ethephon, 2-hydroxyethylphosphonic acid (HEPA), fosetyl aluminum, glyphosate, aminomethylphosphonic acid (AMPA), N-acetyl-glyphosate and N-acetyl-AMPA in tomatoes, oranges, aubergines and grapes. For that purpose, an ultra high performance liquid chromatography (UHPLC) coupled to a high resolution single mass spectrometer Orbitrap-MS were used. Different stationary phases were evaluated for chromatographic separation, and among them, the stationary phase Torus DEA provided the best separation of the selected compounds. The QuPPe method was used for the extraction of the analytes, but slight modifications were needed depending on the matrix. The developed method was validated, observing matrix effect in all matrices. Intra- and inter-day precision were estimated, and relative standard deviation were lower than 19%. Recoveries were satisfactory, and mean values ranged from 70% to 110%. Limits of quantification were between 25 and 100 µg kg^-1. Finally, the analytical method was applied to different fruits and vegetables (oranges, tomatoes, aubergines and grapes).

Rapid and reliable detection of glyphosate in pome fruits, berries, pulses and cereals by flow injection - Mass spectrometry

A flow injection - mass spectrometry method for rapid glyphosate detection in food commodities was developed and validated. The sample preparation protocol included a simple and rapid extract purification step through polymeric solid phase extraction cartridges followed by addition of isotopically labeled glyphosate to the final test sample. The optimized method was subjected to intra-laboratory validation (spiking range 0.5-100 mg/kg) in chickpeas, grapes and apples, as representatives of three different commodity groups as defined in SANTE/11813/2017 guidelines. Recoveries were in the range 60-111%, repeatability and within laboratory reproducibility were ≤17%.The trueness of the results generated with the developed method was evaluated by analysis of a set of incurred chickpea and wheat samples (glyphosate range 0.5-36 mg/kg) and comparison with the reference method (Quick Polar Pesticides Method), confirming the method fitness-for-purpose of rapid compliance testing.