Method validation and application of a selective multiresidue analysis of highly polar pesticides in food matrices using hydrophilic interaction liquid chromatography and mass spectrometry

Direct Determination of Glyphosate and Its Metabolites in Foods of Animal Origin by Liquid Chromatography-Tandem Mass Spectrometry

Glyphosate is the most used herbicide in agriculture. Its major metabolite is AMPA (aminomethylphosphonic acid), but N-acetyl-AMPA and N-acetylglyphosate are also metabolites of interest. For risk assessment, a general residue definition was proposed as the sum of glyphosate, AMPA, N-acetyl-glyphosate and N-acetyl-AMPA, expressed as glyphosate. A confirmatory method for glyphosate in fat, liver and kidneys, as well as a confirmatory method for AMPA and N-acetyl-glyphosate in all matrices, are still missing. In this paper, we present a method for the quantitative determination of glyphosate residues and its metabolites AMPA, N-acetyl-AMPA and N-acetyl-glyphosate by liquid chromatography-mass spectrometry (LC-MS/MS) in adipose tissue, liver, eggs, milk and honey without derivatization. Different chromatographic columns were tested, with the Hypercarb column providing the best results. The analytes were eluted with mobile phases of acidified water with 1.2% formic acid and 0.5% formic acid in acetonitrile. Sample purification procedures were also optimized by varying the solvent extraction mixtures (water, methanol and mixture ψ (methanol, water) = 1:1, each with the addition of 1% formic acid (v/v)), using different sorbents in solid phase extraction (SPE) (polymeric cationic (PCX) and anionic (PAX)) and using dispersive solid phase extraction (dSPE) (C18 and PSA) by modifying the extraction procedures. Finally, the analytes were extracted from the samples with 1% formic acid in water (v/v). Milk and adipose tissue were purified by the addition of dichloromethane, while liver and egg samples were purified by SPE with a mixed cation exchange sorbent and ultrafiltration with cut-off filters. The proposed analytical procedures were validated according to SANTE/11312/2021 guidelines: linearity, limits of quantification, precision and accuracy were determined for all matrices. The limits of quantification (LOQs) ranged from 0.025 to 0.2 mg kg-1. Precision, expressed as relative standard deviation, was <20%, while accuracy, expressed as analytical recovery, ranged from 70% to 120%. During method validation, the measurement uncertainty was estimated to be <50% for all analytes. Good validation parameters according to the SANTE document were achieved for all analytes. Therefore, the method can be considered reliable and sensitive enough for routine monitoring of polar pesticides. The application of the accredited method in routine analysis will provide data that are useful for the re-evaluation of risk assessment studies in foods of animal origin.

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.

Glyphosate as a Food Contaminant: Main Sources, Detection Levels, and Implications for Human and Public Health

Glyphosate is a broad-spectrum pesticide that has become the most widely used herbicide globally. However, concerns have risen regarding its potential health impacts due to food contamination. Studies have detected glyphosate in human blood and urine samples, indicating human exposure and its persistence in the organism. A growing body of literature has reported the health risks concerning glyphosate exposure, suggesting that the daily intake of contaminated food and water poses a public health concern. Furthermore, countries with high glyphosate usage and lenient regulations regarding food and water contamination may face more severe consequences. In this context, in this review, we examined the literature regarding food contamination by glyphosate, discussed its detection methods, and highlighted its risks to human health.

Pesticide residues in animal-derived food: Current state and perspectives

Pesticides are widely used in the cultivation and breeding of agricultural products all over the world. However, their direct use or indirect pollution in animal breeding may lead to residual accumulation, migration, and metabolism in animal-derived foods, posing potential health risks to humans through the food chain. Therefore, it is necessary to detect pesticide residues in animal-derived food using simple, reliable, and sensitive methods. This review summarizes sample extraction and clean-up methods, as well as the instrumental determination technologies such as chromatography and chromatography-mass spectrometry for residual analysis in animal-derived foods, including meat, eggs and milk. Additionally, we perspectives on the future of this field. This information aims to assist relevant researchers in this area, contribute to the development of ideas and novel technical methods for residual detection, metabolic research and risk assessment of pesticides in animal-derived food.

Pesticide contamination pattern from Morocco, insights into the surveillance situation and health risk assessment: a review

The widespread application of pesticides in Morocco's agriculture renders their monitoring in food and environmental samples very necessary. Recent years have witnessed a growing interest in reporting studies related to the monitoring of pesticide residues in food, water, groundwater, and soil as well as their quantitative health risk assessment. Most published studies have been done by university researchers. However, the lack of research reproducibility remains a problem that considerably limits the possibility of exploiting data from the literature. Our study involves an extensive literature review utilizing search engines with keywords like "pesticide residues," "monitoring," "vegetables and fruits," "water and soil," "risk assessment," and "Morocco" from 2009 to 2023. Analysis of pesticide residues in foodstuffs and environmental samples highlights concerns over compliance with EU regulations, the health risks associated with pesticide exposure, and the necessity for comprehensive monitoring and risk assessment strategies. This paper could help influence policies to develop a strategy and action plan for the sound management of pesticides, including measures to reduce their use, raise awareness, and monitor compliance. Also, this paper could be useful for scientists interested in understanding the current situation and challenges regarding pesticide residues in Morocco, as well as countries with which commercial links exist.

Surface multi-walled carbon nanotube modified quaternary amine-functionalized polymers for purification and determination of glyphosate and its four metabolites in plasma samples

The present study focused on the pretreatment and detection of GLY and its four metabolites AMPA, N-acetyl AMPA, N-methyl GLY and N-acetyl GLY in plasma samples. Multi-walled carbon nanotube-modified quaternary amine-functionalized polymers (QA-PDNV@MWCNTs) were synthesized in a controlled manner by self-assembly, and its morphology and composition were extensively characterized. The QA-PDNV@MWCNTs microspheres were then used as an SPE adsorbent for the preparation and rapid determination of GLY and its four metabolites in plasma samples combined with ultra-performance liquid chromatography-high resolution mass spectrometry (UPLCHRMS). The SPE conditions based on QA-PDNV@MWCNTs were optimized for GLY and its metabolites to obtain the best purification efficiency. The experimental results show that when the adsorbent contains 8% MWCNTs, it can balance the adsorption of target analytes and the purification performance of the adsorbent for impurities. In addition, this study compared the QA-PDNV@MWCNTs based SPE method with the commercial Waters Oasis MAX SPE cartridge and the results showed that the developed method in this study has better resistance to matrix interference. Under optimal conditions, the recoveries of GLY and its metabolites spiked in plasma were 82.6-99.4 % with relative standard deviations (RSDs) of 1.0-7.8 %. The limits of detection (LODs, S/N ≥ 3) and limits of quantification (LOQs, S/N ≥ 9) of the method were 0.05-0.33 μg/L and 0.15-1.00 μg/L, respectively. Finally, the developed QA-PDNV@MWCNTs based SPE-UPLCHRMS method was used to confirm GLY poisoning not only on the basis of the detection of the GLY prototype, but also on the basis of its four metabolites.

Development and inter-laboratory validation of analytical methods for glufosinate and its two metabolites in foods of plant origin

Glufosinate is widely used to control various weeds. Glufosinate and its main metabolites have become the focus of attention because of their high water solubility and persistence in aquatic systems. Quantification of the agrochemical product and its metabolite residues is essential for the safety of agricultural products. In this study, a highly specific, simple method was developed to directly determine glufosinate and its metabolite residues in 21 plant origin foods by liquid chromatography with tandem mass spectrometry (LC-MS/MS), and it was validated on 11 foods in five laboratories. Finally, the repeatability limit, reproducibility limit, and uncertainty of the method were calculated based on these validated data and used to support the more accurate detection results. Four different chromatographic columns were used to analyze three target compounds, and the anionic polar pesticide column showed the optimum separation and peak shape. Composition of the mobile phase, extraction solvent, and the clean-up procedure were optimized. The developed method was validated on 21 plant origin foods. The average recoveries were 74-115% for all matrices. The validation results of five laboratories showed this method had a good repeatability (RSDr < 9.5%) and reproducibility (RSDR < 18.9%). The method validation parameters met the requirements of guidance established by the European Union (EU) and China for pesticide residue analysis. This methodology can be used for a routine monitoring that performs well for glufosinate and its metabolite residues.

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.

Quantification of Chlorate and Perchlorate in a Broad Range of Food Commodities, Including Baby Food, Nutritional Formulas, and Ingredients by LC-MS/MS: First Action AOAC 2022.06

BACKGROUND

Chlorate is an effective herbicide, but also a byproduct of chlorinating agents used to disinfect water, which is one of the reasons why it is regularly found in food. Perchlorate is a ubiquitous contaminant, which is naturally occurring in the environment but also released from anthropogenic sources such as the industrial use of certain natural fertilizers. Chlorate affects the hematological system, and perchlorate the thyroid.

OBJECTIVE

Implement and validate a simple and robust analytical method for the accurate determination of chlorate and perchlorate in baby food, infant and adult formulas, and ingredients thereof, which is suited for its application in routine environments where a broad variety of food commodities must be analyzed simultaneously.

METHOD

Typically, analytes are extracted with a mixture of water, acidified methanol, and dichloromethane. Optionally, for dairy products and byproducts, extraction can be performed with water, acidified methanol, and EDTA, followed by two steps of cleanup (freezing out and dispersive solid-phase extraction with C18 in acetonitrile). Quantitative determination is carried out by isotopic dilution liquid chromatography tandem mass spectrometry (LC-MS/MS).

RESULTS

The method was single-laboratory validated in five Nestlé Quality Assurance Centers (NQACs) in a comprehensive range of representative matrixes of different categories such as baby foods, infant/adult formulas, and ingredients, with results generally in agreement with the acceptance criteria of the Standard Method Performance Requirement (SMPR®) 2021.001 defined by AOAC INTERNATIONAL, in terms of representative matrixes validated, LOQs, trueness, and precision.The data generated during validation show that the method proposed is simple, accurate and robust enough to be implemented and applied in routine environments.

CONCLUSION

The data generated during validation show that the method proposed is simple, accurate and robust enough to be implemented and applied in routine environments.

HIGHLIGHTS

The AOAC Expert Review Panel approved the present method as AOAC Official First Action 2022.06.

Facile analysis of mycotoxin in coffee and tea samples using a novel semi-automated in-syringe based fast mycotoxin extraction (FaMEx) technique coupled with direct-injection ESI-MS/MS analysis

Identifying the risk of ochratoxin A in our daily food has become fundamental because of its toxicity. In this work, we report a novel semi-automated in-syringe-based fast mycotoxin extraction (IS-FaMEx) technique coupled with direct-injection electrospray-ionization tandem mass spectrometer (ESI-MS/MS) detection for the quantification of ochratoxin A in coffee and tea samples. Under the optimized conditions, the results reveal that the developed method's linearity was more remarkable, with a correlation coefficient of > 0.999 and > 92% extraction recovery with a precision of 6%. The detection and quantification limits for ochratoxin A were 0.2 and 0.8 ng g-1 for the developed method, respectively, which is lower than the European Union regulatory limit of toxicity for ochratoxin-A (5 ng g-1) in coffee. Furthermore, the newly developed modified IS-FaMEx-ESI-MS/MS exhibited lower signal suppression of 8% with a good green metric score of 0.64. In addition, the IS-FaMEx-ESI-MS/MS showed good extraction recovery, matrix elimination, good detection, and quantification limits with high accuracy and precision due to the fewer extraction steps with semi-automation. Therefore, the presented method can be applied as a potential methodology for the detection of mycotoxins in food products for food safety and quality control purposes.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-023-05733-z.

Low-Temperature Cleanup Followed by Dispersive Solid-Phase Extraction for Determination of Nine Polar Plant Growth Regulators in Herbal Matrices Using Liquid Chromatography-Tandem Mass Spectrometry

Polar plant growth regulators, used alone or doped in fertilizers, are most effective and widely utilized plant growth regulators (PGRs) in agriculture, which play important roles in mediating the yield and quality of crops and foodstuffs. The application scope has been extended to herbal medicines in the past 2 decades and relevant study is inadequate. The aim of this study is to establish a QuPPe-based extraction method containing low-temperature and d-SPE cleanup procedure followed by the detection on a selective multiresidue ultrahigh-performance liquid chromatography - triple quadrupole tandem mass spectrometry (UHPLC-QqQ-MS/MS) in three herbal matrices. This simple, accurate, versatile and robust method was verified according to the validation criteria of the SANTE/12682/2019 guideline document. The analytical range was from 2.5 to 200 μg/L, and the average recoveries were in the range of 64.6-117.8% (n = 6). The optimized method was applied to 135 herbal medicines thereof. Result showed that the detection frequency of chlormequat was the highest in the investigated PGRs, with the positive rate of 15.6%. Improvement of the detection method for polar PGRs will enrich the coverage of PGRs, which is conducive to safeguard public health and ensure drug safety.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10337-023-04254-3.

Determination of Glyphosate in White and Brown Rice with HPLC-ICP-MS/MS

Background: In 2017, the European Commission renewed the approval of glyphosate (GLY) but only for five years. GLY remains one of the most controversial and studied molecules. Method: A simplified method was tested for the determination of GLY in white rice (WR) and brown rice (BR), after extraction only with a methanol solution, by liquid chromatography coupled with inductively coupled mass triple quadrupole (HPLC-ICP-MS/MS) with a PRP-X100 anionic column. After performing a test on groundwater, the quantification of GLY in WR and BR was validated in terms of the LOD, LOQ, accuracy, precision, linearity, and the matrix effect. Results: The LOD was 0.0027 mg kg−1 for WR and 0.0136 mg kg−1 for BR. The LOQ was 0.0092 mg kg−1 for WR and 0.0456 mg kg−1 for BR. The mean recoveries were within 76−105% at three fortification levels. The relative standard deviation for the analysis (five replicates for three spike levels) was < 11% for both matrices. A linear response was confirmed in all cases in the entire concentration range (R2WR = 1.000 and R2BR = 0.9818). Conclusion: The proposed method could be considered useful for the determination of GLY in different types of rice and designed and adapted for other cereals. The matrix effect, quantified in BR matrix extraction, could be avoided by using a matrix-matched calibration line.

Determination of Highly Polar and Ionic Pesticides in Grape and Pomegranate Using Liquid Chromatography Tandem Mass Spectrometry

Background

Residues of polar pesticides cannot be determined by QuEChERS-based multiresidue extractions because of their non-amenability to reverse-phase chromatographic separation and poor recoveries. On the other hand, single-residue methods pose limitations because of the various requirements of sample preparation and LC-MS/MS conditions. A new multiresidue method is thus warranted for rapid and simultaneous analysis of polar pesticides.

Objective

The study developed a multiresidue method for the simultaneous analysis of glyphosate and its metabolite (aminomethylphosphonic acid, AMPA), glufosinate and its metabolites (3-methylphosphinicopropionic acid and N-acetyl-glufosinate), ethephon, fosetyl-aluminum and its metabolite (phosphonic acid), and trimesium in grape and pomegranate by LC-MS/MS.

Method

The homogenized samples (10 g) were extracted with acidified methanol (20 mL). An aliquot of the extract was diluted with acetonitrile (1 + 1) and measured by LC-MS/MS using a Torus DEA column. The performance of a hydrophilic interaction liquid chromatography (HILIC) column and an “anionic polar pesticides” (APP) column was also evaluated.

Results

The method performance on the Torus DEA column was satisfactory for all compounds (recoveries = 77–104%, repeatability-RSD, &lt;11%) at limit of quantification (LOQ) (0.01 mg/kg), and with higher levels in grape and pomegranate. The only exception was AMPA, which had an LOQ of 0.05 mg/kg. In the APP column, AMPA could be determined with an LOQ of 0.01 mg/kg. Trimesium, which had poor retention in Torus DEA, performed better in an XBridge HILIC column (retention time = 4.2 min, LOQ = 0.01 mg/kg). The inter-laboratory validation experiment yielded comparable results with high accuracy and precision.

Conclusions

The method could screen the residues of all compounds on a Torus DEA column. For AMPA and trimesium, the APP and XBridge HILIC columns provided superior method performances. Since isotopically labeled internal standards were not required, the method appeared cost-effective. Considering its compliance with the SANTE/12682/2019 validation guidelines and EU-MRLs, the method can be recommended for regulatory testing purposes.

Highlights

A high-throughput residue analysis method targeting nine polar and ionic compounds in grape and pomegranate involved a single multiresidue extraction, followed by direct analysis using LC-MS/MS. A satisfactory method performance was achieved through intra- and inter-laboratory validation. The method sensitivity met the EU-MRLs and the SANTE/12682/2019 analytical quality control criteria.

Ion Chromatography–High-Resolution Mass Spectrometry Method for the Determination of Bromide Ions in Cereals and Legumes: New Scenario for Global Food Security

The new scenario for global food production and supply is decidedly complex given the current forecast of an increase in food fragility due to international tensions. In this period, exports from other parts of the world require different routes and treatments to preserve the food quality and integrity. Fumigation is a procedure used for the killing, removal, or rendering infertile of pests, with serious dangers to human health. The most-used fumigants are methyl bromide and ethylene dibromide. It is important to bear in mind that the soil may contain bromide ions naturally or from anthropogenic source (fertilizers and pesticides that contain bromide or previous fumigations). Different methods (titrimetric, spectrophotometric, and fluorometric approaches) are available to rapidly determine the amount of bromide ion on site in the containers, but these are non-specific and with high limits of quantification. The increasing interest in healthy food, without xenobiotic residues, requires the use of more sensitive, specific, and accurate analytical methods. In order to help give an overview of the bromide ion scenario, a new, fast method was developed and validated according to SANTE 11312/2021. It involves the determination of bromide ion in cereals and legumes through ion chromatography–Q-Orbitrap. The extraction was performed by the QuPPe method, but some modifications were applied based on the matrix. The method described here was validated at four different levels. Recoveries were satisfactory and the mean values ranged between 99 and 106%, with a relative standard deviation lower than 3%. The linearity in the matrix was evaluated to be between 0.010 and 2.5 mg kg⁻¹, with a coefficient of determination (R²) of 0.9962. Finally, the proposed method was applied to different cereals and legumes (rice, wheat, beans, lentils pearled barley, and spelt) and tested with satisfactory results in EUPT-SMR16 organized by EURL.

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.

Pesticides in fruits and vegetables from the Souss Massa region, Morocco

This survey reports the monitoring of multi-pesticide residues of some fruits and vegetables sold in the local markets, sampled in 2018-2019, in the Souss Massa region in Morocco. A QuEChERS-LC-MS/MS method for 202 pesticides, belonging to different classes (carbamates, organophosphorus and organonitrogen pesticides) was applied and 51 samples were randomly bought from the local market, belonging to different products (tomato, cucumber, coriander, apricot, parsley, potato, zucchini, green bean, lettuce, strawberry and orange) and analysed for pesticide residues, which were detected in 69% of the samples, below the maximum residue limits (MRLs) for some pesticides which represent 14% of the targeted compounds. The most frequently detected compounds were acetamiprid, acibenzolar-s-methyl, abamectin, azoxystrobin, bifenazate, bitertanol, bromuconazole, butoxycarboxim, cyromazine, difenoconazole, epoxiconazole, fenbuconazole, fluometuron, linuron, metaflumizone, metconazole, metribuzin, myclobutanil, pirimicarb, pyraclostrobin, propamocarb, rotenone, trichlorfon, tebuconazole, tetraconazole, thiamethoxam and thiophanate-methyl. The obtained results provide a value to the situation of pesticide residues in Morocco.

Determination of glyphosate exposure in the Iberian hare: A potential focal species associated to agrosystems

Glyphosate is the most used herbicide worldwide. It is a small and highly polar pesticide whose physicochemical properties makes its analytical determination difficult. Here, a procedure based on liquid chromatography-high resolution tandem mass spectrometry (LC-HRMS/MS) was developed for glyphosate determination in samples of gastric content from wildlife. Iberian hare (Lepus granatensis), a herbivorous mammal species, strongly associated to agrosystems was selected as model species. The procedure involves direct analysis of sample without derivatization or instead of neither further cleaning steps. The procedure was validated by inter-day accuracy and precision studies with gastric content of hare spiked with glyphosate at ecologically relevant concentrations for the species (0.1-6 μg/g), and with 1 μg/g of isotopically labelled internal standard (glyphosate-2-13C,15N). Finally, glyphosate residues in hunted animals from pesticide-treated and pesticide-free areas (n = 75 and 28, respectively), as well as from hares found dead in the field (n = 11) were analysed. The linearity of both standards in extraction solutions and procedural calibration curves with spiked samples was similar, both with determination coefficients (r2) higher than 0.99. Satisfactory recoveries in spiked samples were achieved within the range of 95% to 118% (CV ≤ 20%). The limit of detection of glyphosate in hare gastric content was 0.03 μg/g. Prevalence of glyphosate in hunted animals from pesticide-treated areas ranged between 9 and 22%, increasing to 45% in animals found dead. The glyphosate concentrations detected in the gastric content of hares ranged from 0.11 to 16 μg/g. No residues were detected in animals from pesticide-free areas. In practice, the developed methodology may be particularly useful in the context of research and other work on the exposure in wildlife of one of the most used pesticides nowadays.

Evaluation of pesticide residues and risk assessment in apple and grape from western Azerbaijan Province of Iran

West Azerbaijan, especially the city of Urmia, is the center of Iranian apple and grape production hence the importance of this, residues of 85 pesticides in these products were investigated using modified QuEChERS extraction followed by UHPLC-MS/MS technique. Residues of 17 different pesticides detected in some apple samples. In grape sample only 7 pesticides detected. The levels of the residues found in all apple and grape samples were below the maximum residue levels (MRLs) of Iran, except for iprodione. Health risk assessment associated with pesticide residues in apples and grapes were estimated by hazard quotient (HQ) and hazard index (HI), which indicated that the HI value was lower than 1 in adults and children due to apple and consumption. HI in adults and children were 0.012 and 0.054 in apple; 0.001 and 0.003 in grape samples, respectively. Although the health risk assessment showed that the consumers are not at considerable risk but due to pesticide residue, implement control plans to manage the proper application of this pesticide, or replace it with safer alternatives in apple and grape is required.

Approaches to liquid chromatography tandem mass spectrometry assessment of glyphosate residues in wine

The performance of two different analytical methodologies to investigate the presence of glyphosate (GLY) and aminomethylphosphonic acid (AMPA) residues in wine samples was evaluated. Transformation of compounds in their fluorene-9-methyloxycarbonyl derivatives permitted their separation under reversed-phase liquid chromatography with tandem mass spectrometry (LC-MS/MS) determination. Although the wine matrix severely impaired the efficiency of GLY derivatization, this drawback was solved using a molecularly imprinted sorbent for the previous, selective extraction of GLY and AMPA from wine. Alternatively, the use of a strong anionic exchange, polyvinyl alcohol-based LC column, turned to be the most effective alternative for direct determination of both compounds in diluted wine samples. The chromatographic behavior of this column and the magnitude of matrix effects observed during analysis of diluted wine samples were significantly affected by the composition of the mobile phase. Under final working conditions, this column permitted the separation of AMPA and the fungicide fosetyl (which shows common transitions in tandem MS/MS methods), it improved significantly the sample throughput versus extraction-derivatization-purification method, and it allowed the use of solvent-based calibration standards. Both analytical procedures provided similar limits of quantification (LOQs) for GLY (0.5-1.0 ng mL-1), while the multistep method was 8 times more sensitive to AMPA than the direct procedure. GLY residues stayed above method LOQs in 70% of the processed wines; however, concentrations measured in 95% of positive samples remained 100 times below the maximum residue limit (MRL) set for GLY in vinification grapes.

Determination of Glyphosate and AMPA in Food Samples Using Membrane Extraction Technique for Analytes Preconcentration

The method for determining glyphosate (NPG) and its metabolite AMPA (aminomethyl phosphonic acid) in solid food samples using UAE-SLM-HPLC–PDA technique was developed. Firstly, ultrasonic-assisted solvent extraction (UAE) and protein precipitation step were used for the analyte isolation. Then, the supernatant was evaporated to dryness and redissolved in distilled water (100 mL). The obtained solution was alkalized to pH 11 (with 1 M NaOH) and used directly as donor phase in SLM (supported liquid membrane) extraction. The SLM extraction was performed using 2 M NaCl (5 mL) as an acceptor phase. The flow rate of both phases (donor and acceptor) was set at 0.2 mL/min. The membrane extraction took 24 h but did not require any additional workload. Finally, the SLM extracts were analyzed using the HPLC technique with photo-diode array detector (PDA) and an application of pre-column derivatization with p-toluenesulfonyl chloride. Glyphosate residues were determined in food samples of walnuts, soybeans, barley and lentil samples. The LOD values obtained for the studied food were 0.002 μg g⁻¹ and 0.021 μg g⁻¹ for NPG and AMPA, respectively. Recoveries values ranged from 32% to 69% for NPG, 29% to 56% for AMPA and depended on the type of sample matrix. In the case of buckwheat and rice flour samples, the content of NPG and AMPA was below the detection level of a used analytical method.

Determination of Fosetyl-Aluminum in Wheat Flour with Extract-Dilute-Shoot Procedure and Hydrophilic Interaction Liquid Chromatography Tandem Mass Spectrometry

Fosetyl-aluminum is a widely used ionic fungicide. This pesticide is not amenable to the common multi-residue sample preparation methods. Herein, this paper describes a novel method for the simple and sensitive determination of fosetyl-aluminum residue in wheat flour. The sample preparation method involved extraction with water under ultrasonication and subsequent dilution with six-fold acetonitrile. The fosetyl-aluminum concentration was determined by hydrophilic interaction liquid chromatography tandem mass spectrometry. The limit of detection and quantification were only 5 and 10 ng/g, respectively, which meet the requirement of the current European legislation. Matrix-matched linearity (r2 = 0.9999) was established in the range of 10–2000 ng/g. Satisfactory recoveries were achieved in the range of 95.6% to 105.2% for three levels of spiked samples (10, 50, and 100 ng/g). Finally, the method was applied to analyzing 75 wheat flour samples produced in four provinces in China. Two samples were positive with concentrations over the limit of detection. This is the first method focusing on fosetyl-aluminum determination in wheat flour with an extract-dilute-shoot strategy and is very promising for the routine quality control of fosetyl-aluminum in similar cereal matrices.

Current Strategies for Studying the Natural and Synthetic Bioactive Compounds in Food by Chromatographic Separation Techniques

The present study summarizes the new strategies including advanced equipment and validation parameters of liquid and gas chromatography methods i.e., thin-layer chromatography (TLC), column liquid chromatography (CLC), and gas chromatography (GC) suitable for the identification and quantitative determination of different natural and synthetic bioactive compounds present in food and food products, which play an important role in human health, within the period of 2019–2021 (January). Full characteristic of some of these procedures with their validation parameters is discussed in this work. The present review confirms the vital role of HPLC methodology in combination with different detection modes i.e., HPLC-UV, HPLC-DAD, HPLC-MS, and HPLC-MS/MS for the determination of natural and synthetic bioactive molecules for different purposes i.e., to characterize the chemical composition of food as well as in the multi-residue analysis of pesticides, NSAIDs, antibiotics, steroids, and others in food and food products.

Fabrication and evaluation of tetraazahexaphenylmacrocycle-bonded stationary phase with multiple retention mechanisms

A 34-membered tetraazahexaphenylmacrocycle (N₄Ph₆) with a rigid π-conjugated moiety was chemically bonded to silica gel with 3-chloropropyltrimethoxysilane as the coupling agent to prepare a novel SiO₂@N₄Ph₆ stationary phase. Several common organic analytes, including alkylbenzenes, polycyclic aromatic hydrocarbons, anilines, phenols, phthalates, and folic acid, were selected as probes to investigate its chromatographic performance. The as-developed SiO₂@N₄Ph₆ stationary phase showed superiority retention and high selectivity for probe molecules through multiple interactions, including hydrophobic, π-π, hydrogen-bonding, and steric interactions. Density functional theory calculation results using folic acid as model solute provided an intuitive and a quantitative description of the multiple retention mechanisms.

Determination of glyphosate and AMPA in oat products for the selection of candidate reference materials

The use of reference materials (RMs) is critical for validating and testing the accuracy of analytical protocols. The National Institute of Standards and Technology (NIST) is in initial stages of developing a glyphosate in oats RM. The first aim of this study was to optimize and validate a robust method for the extraction and analysis of glyphosate and aminomethylphosphonic acid (AMPA). The optimized method was used to screen thirteen commercially available oat products to identify candidate RMs. Glyphosate was detected in all samples, with the highest glyphosate mass fraction of 1100 ng/g; lower levels were measured in grains from organic agriculture. AMPA was quantified in nine samples up to 40 ng/g. The findings of this study led to the identification of candidate RMs, with "high" and "low" glyphosate levels. A preliminary stability study determined that glyphosate is stable in oat material at room temperature for six months.

Influence of different hydrophilic interaction liquid chromatography stationary phases on method performance for the determination of highly polar anionic pesticides in complex feed matrices

Hydrophilic interaction liquid chromatography is an alternative liquid chromatography mode for separation of polar compounds. In the recent years, this liquid chromatography mode has been recognized as an important solution for the analysis of compounds not amenable to reverse phase chromatography. In this work, we evaluated three different hydrophilic liquid chromatography stationary phases for the determination of 14 highly polar anionic molecules including pesticides such as glyphosate, glufosinate, ethephon and fosetyl, their main metabolites, and bromide, chlorate, and perchlorate. Several mobile phase compositions were evaluated combined with different gradients for the chromatographic run. The two columns that presented the best results were used to assess the performance for the determination of the 14 compounds in challenging highly complex feed materials. Very different matrix effects were observed for most of the compounds in each column, suggesting that different interactions can occur. Using isotopically labeled internal standards, acceptable quantitative performance and identification could be achieved down to 0.02 mg kg^-1 (the lowest level tested) for most compounds. While one column was found to be favorable in terms of scope (suited for all 14 compounds), the other one was more suited for quantification and identification at lower levels, however, not for all analytes tested.

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.

Monitoring of polar pesticides and contaminants in edible oils and nuts by liquid chromatography-tandem mass spectrometry

A single method was developed for the determination of polar pesticides (fosetyl-Al and its metabolite, phosphonic acid, and ethephon) and environmental contaminants (chlorate and perchlorate) in edible oils and nuts. Two extraction methods based on QuPPe-PO approach (Quick Polar Pesticides Method for products of Plant Origin) were optimized. In oils, a single extraction using water acidified with formic acid (1%) was performed, while in nuts, the clean-up step was modified. C18 was used as sorbent and an extra cleaning step with n-hexane was added. The extracts were analysed by liquid chromatography coupled to a triple quadrupole mass analyser (LC-QqQ-MS/MS). The method was validated and the limit of quantification was 0.01 mg kg^-1 for all analyte-matrix combination. Recoveries from 70 to 120%, and intra and inter-day precision values ≤20% were obtained. Forty samples of edible oils and nuts were analysed, detecting phosphonic acid in nuts at concentrations up to 4.6 mg kg^-1.

Direct Analysis of Glyphosate, Glufosinate, and Their Metabolites in Palm Oil Using Liquid Chromatography with Tandem Mass Spectrometry

BACKGROUND

Glyphosate and glufosinate are broad-spectrum herbicides which are frequently used in palm oil plantations for weed control. Metabolites of these herbicides are known to have environmental and food safety implications. As there is no validated method for multiresidue testing of these herbicides and their metabolites in palm oil products, a new method was needed for the purpose of regulatory analysis.

OBJECTIVE

In this study, we endeavored to develop a rapid method for multiresidue analysis of glyphosate (+aminomethylphosphonic acid) and glufosinate (+3-methylphosphinicopropionic acid and N-acetyl-glufosinate) in refined and crude palm oil matrices using liquid chromatography (LC) tandem mass spectrometry (MS/MS).

METHOD

The optimized sample preparation workflow included extraction of refined or crude palm oil (10 g) with acidified water (0.1 M HCl), cleanup by phase separation with dichloromethane, and analysis by LC-MS/MS with multiple reaction monitoring.

RESULTS

The use of a Torus-DEA LC column ensured simultaneous analysis of these compounds within a runtime of 10 min. The LOQ of these analytes was 0.01 mg/kg, except that of aminomethylphosphonic acid which was 0.02 mg/kg. The method sensitivity complied with the national maximum residue limits of Malaysia and the European Union. Also, the method selectivity, sensitivity, accuracy, and precision were aligned with the SANTE/12682/2019 guidelines of analytical quality control.

CONCLUSIONS

The potentiality of the optimized method lies in a high throughput direct analysis of glyphosate and glufosinate with their metabolites in a single chromatographic run. The method is fit for purpose for regulatory testing of these residues in a broad range of palm oil matrices.

HIGHLIGHTS

The study reports for the first time a validated method for simultaneous analysis of glyphosate, glufosinate, and their metabolites in a range of palm oil products. The method did not require a derivatization step and provided a high throughput analysis of these compounds with satisfactory selectivity, sensitivity, accuracy, and precision.

Effect of household rice cooking on pesticide residues

This investigation shows the pesticide distribution and reduction using three common household cooking methods. Extraction was performed using QuEChERS and solid phase microextraction methodologies for rice and water, respectively. Gas chromatography-mass spectrometry was used. Both methods showed good linearity (r² > 0.9996 and 0.9945), adequate recoveries (between 98.9 and 107.8% and 90.5-104.2%) and relative standard deviations lower than 4.5% and 7.0%, for rice and water, respectively. The initial concentration of deltamethrin, penconazole, kresoxim-methyl, cyproconazole, epoxiconazole and azoxystrobin, were 84.9, 242.2, 298.5, 230.7, 253.4 and 293.5 µg/kg, respectively. Washing and soaking water reduce pesticides only 0.40 to 4.28%. The pesticide reduction during cooking were 20.73 to 57.72%, 32.74 to 70.39%, and 68.87 to 87.50% for traditional, excess water, and pre-soaking rice methods, respectively. Pre-soaking rice with extra water before cooking proved to be the method that generates the greatest reduction.

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.

Retention behavior of ginsenosides in a sulfo-based high performance liquid chromatography column

We herein report the use of a sulfo-based column and hydrophilic interaction chromatography (HILIC) to separate 14 ginsenosides, namely Rb1, Rb2, Rb3, Rc, Rd, Rf, Re, Rg1, Rg2, Rg3, Rh1, Rh2, F₂, and C-K. In addition to its rapid and efficient ability to separate these ginsenosides, the sulfo-based column exhibited a good relationship between the ginsenoside capacity factor (k') and molecular weight (M_w) and a strict elution order corresponding to the polarity (P) of the ginsenosides, as confirmed by thin layer chromatography.