Fate of multi-residue insecticides and their metabolites in the process of vinification: Analytical method validation, dissipation kinetics, processing factor, and risk assessment.

In viticulture, the use of synthetic chemical formulations introduces insecticide residues into harvested grapes and further into processed grape products, posing a safety concern to consumers. This study investigated the fate of ten insecticide residues and their metabolites from vine to wine. A rapid validated multi-residue approach using QuEChERS extraction and LC-MS/MS configuration was employed for targeted analysis in grape, pomace, and wine. The targeted insecticides showed satisfactory mean recoveries (76.03-111.95%) and precision (RSD = 0.75-7.90%) across the three matrices, with a matrix effect ranging from -16.88 to 35.18%, particularly higher in pomace. Preliminary grape washing effectively removed 15.52-61.31% of insecticide residues based on water solubility and systemic nature. Residue dissipation during fermentation ranged from 73.19% to 87.15% with a half-life spanning from 1 to 5.5 days. The mitigation rate was observed at 12.85-26.81% for wine and 17.76-51.55% for pomace, with the highest transfer rate for buprofezin (51.55%) to pomace and fipronil (25.72%) to wine. Calculated processing factors (PF) for final wine ranged from 0.16 to 0.44, correlating strongly with the octanol-water partition ratio of targeted insecticides. The reported PF, calculated hazard quotient (HQ) (0.003-5.800%), and chronic hazard index (cHI) (2.041-10.387%) indicate reduced residue concentrations in wine and no potential chronic risk to consumers, ensuring a lower dietary risk to wine consumers.

Method development and validation in the curry leaf matrix employing advanced mass spectrometry: quantitative screening of 490 multiclass pesticides by buffered ethyl acetate technique.

Curry leaf is an evergreen herb with culinary, pharmaceutical, and nutraceutical applications. As pesticide residue in curry leaf has garnered significant regulatory attention in recent years, here we report a reliable method, which was validated for the determination of 265 and 225 pesticides using LC-MS/MS and GC-MS/MS, respectively. At first, the sample was comminuted after adding water (1:2). The sample preparation workflow included extraction of 10 g homogenized sample with 10 mL ethyl acetate (+1% acetic acid), cleanup by dispersive solid phase extraction (d-SPE, 50 mg PSA + 50 mg C18 + 10 mg GCB + 150 mg Na2SO4) and the final analysis by tandem mass spectrometry. The cleanup step adeptly removed co-extractives. The method effectively reduced matrix effects and offered an LOQ of 0.01 mg kg-1 for most compounds. The method's accuracy and precision results fulfilled the requirements of SANTE/11312/2021 guidelines at 0.01 mg kg-1 and higher levels of fortification. The accuracy and precision results were comparable for all pesticides. The successful screening of market samples indicates its high extraction efficiency and precision for incurred residue analysis. Due to its robustness and conformity with regulatory criteria, food testing laboratories worldwide can use the method to monitor pesticide levels in curry leaves.

Dissipation kinetics, safety evaluation, and decontamination of residues of the combo-formulation iprovalicarb 8.4% + copper oxychloride 40.6% WG in/on grapes (Vitis vinifera L.).

A field experiment was conducted to study the dissipation behavior and decontamination of iprovalicarb and copper oxychloride in grapes. After thorough validation, the analysis was carried out by employing LC-MS/MS for iprovalicarb and AAS for copper oxychloride. The dissipation pattern of residues followed a linear first-order kinetics model for both the test fungicides. The half-life values for iprovalicarb were 9.5-13.5 days, and for copper oxychloride was 24.5 days. Based on the study, a pre-harvest interval (PHI) of 17 days is proposed for the formulation. In decontamination studies, combination treatment of 0.1% sodium bicarbonate + ultrasonication and 2% lemon water + ultrasonication has shown the highest reduction of iprovalicarb (90.02% reduction) and copper oxychloride (80.14% reduction) residues, respectively. The safety evaluation data suggest that the daily exposure at all the sampling points was less than the maximum permissible intake (MPI) calculated indicating, safety to consumers. This study will be useful for promoting effective residue management and the safe use of these chemicals for controlling fungal diseases in grapes.

Multi-residue method validation and safety evaluation of pesticide residues in seed spices cumin (Cuminum cyminum) and coriander (Coriandrum sativum) by gas chromatography tandem mass spectrometry (GC-MS/MS).

The manuscript reports comprehensive multi-residue determination of 215 pesticides in two commercially important Indian spices, Cumin (Cuminum cyminum) and Coriander (Coriandrum sativum) by GC-MS/MS analysis. The proposed method involved liquid-liquid extraction with acetonitrile, d-SPE clean-up and final reconstitution of extract in ethyl acetate. d-SPE clean-up with PSA and C18 minimized the matrix effects by 40 and 16%, respectively. Reconstitution of final extract reduced the non-volatile matrix co-extractives by 36-40%. The method was validated as per SANTE/12682/2019 and recoveries at 10, 25 and 50 µg kg-1 were within 70-120% with RSD ≤ 20%. A fit for purpose method LOQ of 10 µgkg-1 was achieved for 85% of analytes. The method was successfully applied for comprehensive screening of cumin and coriander market samples. The calculated TMDI for acute and chronic exposure assessment were less than calculated MPI in respective matrices and therefore did not cause any adverse effect to consumers.

Single-Laboratory Validation of a Multi-residue Method for Simultaneous Analysis of Multi-class Pesticides in Turmeric by Liquid Chromatography Tandem Mass Spectrometry.

BACKGROUND: For years, turmeric has been used in several cuisines worldwide because of its proven health benefits. However, as its cultivation often involves applications of polar and semi-polar pesticides, their residues might cause health hazards to consumers. The dearth of a validated LC-MS/MS method for the residue analysis of these pesticides in turmeric has warranted the present study. OBJECTIVE: The aim was to develop and validate a multi-residue method for simultaneous determination of multi-class pesticides in turmeric (both rhizome and powder) by LC-MS/MS. METHOD: Both the rhizome and powder samples (1 kg) were soaked in water for 30 min, followed by homogenization. Each homogenate (2 g) was mixed with 10 mL water, and extracted with acetonitrile (10 mL) in the presence of acetic acid and NaCl. The extract was cleaned by using dispersive solid phase extraction (dSPE) with graphitized carbon (5 mg/mL) sorbent. The cleaned extract was measured by LC-MS/MS with a runtime of 20 min. The method was validated on 211 multi-class pesticides. RESULTS: The method performance was satisfactory at 10 ng/g and higher levels, in compliance with the SANTE/12682/2019 guidelines. The dSPE cleanup was effective in minimizing the matrix effects. The use of matrix-matched calibrations specific for turmeric powder and rhizome corrected all recoveries within the satisfactory range of 70-120%. The precision -RSDs were <20% for all test pesticides. The Horwitz ratio and measurement uncertainty results were satisfactory as well. CONCLUSIONS: As the method was convenient, selective, accurate, and repeatable, it is recommended for regulatory and commercial testing purposes. HIGHLIGHTS: For the first time, this study reports a validated LC-MS/MS method for the multi-residue analysis of pesticides in turmeric. The method provided a high throughput analysis of multi-class pesticides in turmeric rhizome and powder matrices with satisfactory selectivity, sensitivity, accuracy, and precision. The method performance satisfied the requirements of the SANTE/12682/2019 guidelines, and the method sensitivity complied with the EU-MRL requirements.

Multiresidue Analysis of Pesticides in Moringa Pods by GC-MS/MS and LC-MS/MS.

BACKGROUND: Moringa pods are known for their nutritional and health benefits. The cultivation of this crop receives frequent pesticide applications. In the absence of risk assessment data, maximum residue limits of pesticides in this crop are considered at the default level (0.01 mg/kg). However, there exists scarcely any validated method for pesticide residue analysis in this matrix. OBJECTIVE: This study was undertaken to develop and validate a multiresidue method for the simultaneous analysis of multi-class pesticides in moringa pods by gas chromatography-tandem mass spectrometry (GC-MS/MS), and liquid chromatography-tandem mass spectrometry (LC-MS/MS). METHOD: The homogenized sample (10 g) was extracted with acetonitrile (10 mL). The extract was cleaned by dispersive solid-phase extraction using a combination of 50 mg primary secondary amine, 5 mg graphitized carbon black, and 25 mg C18 sorbents, and was directly analyzed by LC-MS/MS. Another portion of the extract was reconstituted in ethyl acetate before GC-MS/MS analysis. The method was validated as per the SANTE/12682/2019 guidelines using GC-MS/MS (180 pesticides) and LC-MS/MS instruments (203 pesticides). RESULTS: The method provided a satisfactory analysis of the targeted pesticides with good calibration linearity (r2>0.99), high precision (RSD < 20%), and accuracy (recoveries, 70 to 120%). The reconstitution of the acetonitrile extract in ethyl acetate significantly reduced the matrix effects on GC-MS/MS analysis. The use of matrix-matched standards could correct all recoveries. CONCLUSIONS: The method offered a large-scale analysis of multi-class pesticides with high accuracy, and precision at 10 ng/g, and higher levels. The method performance complied with the regulatory requirements, and thus, can be implemented in routine testing purposes. HIGHLIGHTS: The study reports a validated method for large-scale multiresidue analysis of pesticides in moringa matrix for the first time. The method provided a high throughput analysis of multi-class pesticides with satisfactory selectivity, sensitivity, accuracy, and precision.

Residue dissipation, evaluation of processing factor and safety assessment of hexythiazox and bifenazate residues during drying of grape to raisin.

An analytical method for the simultaneous analysis of hexythiazox and bifenazate residues in grape and raisin was validated by liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. The extraction method involved liquid-liquid extraction with ethyl acetate and dSPE cleanup with primary secondary amine (PSA). The drying of grape to raisin may increase or decrease residues of pesticides. During the raisin making process, the dissipation of residue was evaluated and the processing factor (PF) was established for drying. Dissipation data were best fitted to 1st + 1st-order kinetics with a half-life ranging between 6-10 days for hexythiazox and 5-6 days for bifenazate. The PF value for overall raisin making was found to be 0.20-0.36 for hexythiazox and 0.14-0.15 for bifenazate indicating degradation of the residues. However, the PF value varies between 1.13-1.64 for hexythiazox and 0.94-1.12 for bifenazate during the drying process indicating concentration of the residues in drying. The dietary exposure on each sampling day was less than the respective maximum permissible intake (MPI). The residues in market samples of raisins were devoid of any risk of acute toxicity related to dietary exposure. The PF value generated will be useful for the field level management of residues in grape intended for raisin preparation.

Analytical method validation, dissipation and safety evaluation of combination fungicides fenamidone + mancozeb and iprovalicarb + propineb in/on tomato.

Dissipation behavior and degradation kinetics of fenamidone + mancozeb (Sectin 60 WG) and iprovalicarb + propineb (Melody Duo 66.75 WP) in tomato were studied at recommended dose (RD) and double dose (DD) of application. The analysis of the field samples were carried out by employing liquid chromatography tandem mass spectrometry (LC-MS/MS) for fenamidone and iprovalicarb residues and gas chromatography mass spectrometry for mancozeb and propineb residues after thorough validation of the extraction methods. The dissipation of residues best followed 1st + 1st order for all the test fungicides. The half-life period for fenamidone, mancozeb, iprovalicarb and propineb were 2, 2, 1.5 and 2 days for RD and 3, 2.5, 2 and 3 days for DD, respectively. The pre-harvest intervals were not applicable for iprovalicarb, fenamidone and mancozeb (at RD) as the residues at 0 day were below maximum residue limit set by European Union, and it was 1 day for DD of iprovalicarb, 3.5 days for DD of fenamidone, 3 days for DD of mancozeb, 3 and 7 days for propineb at RD and DD, respectively. A PHI of 4 and 7 days are proposed for fenamidone + Mancozeb and iprovalicarb + propineb, respectively. Dietary exposure calculated for all the pesticides were safe on all the sampling days except for propineb residues for which it was safe after first day of the double dose application. The study will be useful for promoting effective residue management and safe use of these chemicals for controlling fungal diseases in tomato crop.

Targeted screening and safety evaluation of 276 agrochemical residues in raisins using buffered ethyl acetate extraction and liquid chromatography-tandem mass spectrometry analysis.

A buffered ethyl acetate extraction method was optimized and validated in raisin matrix to monitor 276 pesticides by liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. The final method involved homogenization of raisinsalong with water 1:1 raisins: water followed by extraction using ethyl acetate (10 mL/10 g raisins homogenate in presence of 0.1 mL acetic acid, 0.5 g sodium acetate and 10 g sodium sulfate, and cleanup by dispersive solid phase extraction with primary secondary amine sorbent (25 mg/5 mL extract). 276 pesticides were estimated within 20 min of chromatographic run time by retention time dependent 'scheduled multiple reaction monitoring' (sMRM) by LC-MS/MS.The method was validated as per European guideline, DG-SANTE/11945/2015, at 2, 10, and 25 ng/g spiking levels where the method precision in terms of repeatability was <15% at 10 ng/g for 93.8% of the compounds. The Limit of quantification (LOQ) ranged between 0.01 and 10 ng/g with recoveries 70-120% with ≤20% RSD for 93.5% of compounds at regulatory default MRL of 10 ng/g. The matrix induced signal suppressions or enhancement were moderate (60-130% accuracy against solvent standard) for 85% compounds in white raisins and 67% compounds in black raisins. The method was successfully applied for screening of 94 market samples of raisins for the target analytes. The dietaryexposures calculated against the average concentrations detected were wellbelow the maximum permissible intake (MPI) values and the collected raisin samples were considered safe for human consumption without any acute toxicity hazard.

Optimization and Validation of a Residue Analysis Method for Glyphosate, Glufosinate, and Their Metabolites in Plant Matrixes by Liquid Chromatography with Tandem Mass Spectrometry.

A sensitive and accurate LC with tandem MS (MS/MS)-based method was developed and validated for the analysis of the herbicide glyphosate, its metabolite aminomethylphosphonic acid (AMPA), and glufosinate after derivatization with 9-fluorenylmethyl chloroformate (FMOC-Cl) in various plant matrixes. The method also covers direct analysis of the glufosinate metabolites 3-methylphosphinicopropionic acid (3-MPPA) and N-acetyl-glufosinate (NAG). The homogenized samples were extracted with 0.1% formic acid in water-dichloromethane (50 + 50). The aqueous layer was derivatized with FMOC-Cl, cleaned through an HLB SPE cartridge, and determined by LC-MS/MS. The sample size, extraction solvent, sample-to-solvent ratio, derivatization conditions, and cleanup procedure were thoroughly optimized, the LOQs of glyphosate, glufosinate, and AMPA were 0.5 ng/g in grape, corn (leaf and seed), and cotton (leaf, seed, and oil) and 2 ng/g in soybean and tea. The LOQs of NAG and 3-MPPA were 50 ng/g in all the test matrixes, except tea and soybean, for which the LOQ was 100 ng/g. In all cases, average recoveries were >80%. The method successfully performed the estimation of glyphosate in incurred corn and cotton leaf samples collected from supervised field trials.

Simultaneous analysis of herbicides pendimethalin, oxyfluorfen, imazethapyr and quizalofop-p-ethyl by LC-MS/MS and safety evaluation of their harvest time residues in peanut (Arachis hypogaea L.).

This paper reports a simple and rapid method for simultaneous determination of the residues of selected herbicides viz. pendimethalin, oxyfluorfen, imazethapyr and quizalofop-p-ethyl in peanut by liquid chromatography-tandem mass spectrometry (LC-MS/MS). A modified approach of the QuEChERS methodology was used to extract the herbicides from the peanut kernel without any clean-up. The method showed excellent linearity (r(2) > 0.99) with no significant matrix effect. Accuracy of the method in terms of average recoveries of all the four herbicides ranged between 69.4 -94.4 % at spiking levels of 0.05, 0.10 and 0.25 mg kg(-1) with intra-day and inter-day precision RSD (%) between 2.6-16.6 and 8.0-11.3, respectively. Limit of quantification (LOQs) was 5.0 µg kg(-1) for pendimethalin, imazethapyr and quizalofop-p-ethyl and 10.0 µg kg(-1) for oxyfluorfen. The expanded uncertainties were <11 % for determination of these herbicides in peanut. The proposed method was successfully applied for analysis of these herbicide residues in peanut samples harvested from the experimental field and the residues were below the detection level.

Residue analysis of fipronil and difenoconazole in okra by liquid chromatography tandem mass spectrometry and their food safety evaluation.

A liquid chromatography tandem mass spectrometry (LC-MS/MS) based method is reported for simultaneous analysis of fipronil (plus its metabolites) and difenoconazole residues in okra. The sample preparation method involving extraction with ethyl acetate provided 80-107% recoveries for both the pesticides with precision RSD within 4-17% estimated at the limits of quantification (LOQ, fipronil=1ngg(-1), difenoconazole=5ngg(-1)) and higher fortification levels. In field, both the pesticides dissipated with half-life of 2.5days. The estimated pre-harvest intervals (PHI) for fipronil and difenoconazole were 15 and 19.5days, and 4 and 6.5days at single and double dose of field applications, respectively. Decontamination of incurred residues by washing and different cooking treatments was quite efficient in minimizing the residue load of both the chemicals. Okra samples harvested after the estimated PHIs were found safe for human consumption.

Dissipation pattern, safety evaluation, and generation of processing factor (PF) for pyraclostrobin and metiram residues in grapes during raisin preparation.

A residue analysis method was validated for trace level estimation of pyraclostrobin by liquid chromatography-mass spectrometry and metiram (analyzed as CS2) by gas chromatography mass spectrometry in grapes and raisin matrix. Dissipation of their residues and processing factors (PFs) during raisin making were evaluated through field studies with applications at single dose (SD) and double dose (DD). Residue data during drying process were best fitted to first + first-order kinetics model giving half-life ranging between 6 and 7 days for pyroclostrobin and 4 days for metiram. PFs for metiram and pyraclostrobin related to washing and oil dipping were 0.47 and 0.41, and 0.78 and 0.63 at single dose (SD) and double dose (DD), respectively. PF value of >1 for drying (1.01 and 1.31 for metiram and 1.34 and 1.10 for pyraclostrobin) indicates concentration of the residues during the drying process. The dietary exposure corresponding to average daily consumption of 0.0043 kg raisin per day on each sampling day was less than the respective maximum permissible intake at both the doses.

Residue dissipation and processing factor for dimethomorph, famoxadone and cymoxanil during raisin preparation.

A method was validated for the simultaneous analysis of the residues of dimethomorph, famoxadone and cymoxanil in grape and raisin matrix by ethyl acetate based extraction and liquid chromatography tandem mass spectrometric analysis. Field studies were conducted to evaluate the dissipation rate kinetics and processing factor (PF) for these pesticides during raisin making. Residue data during the drying process were best fitted to 1st+1st order rate kinetics with half-life ranging between 8-9 days for dimethomorph, 12-13 days for famoxadone and 9-10 days for cymoxanil at single dose (SD) and double dose (DD), respectively. PF values calculated were 1.03 and 1.14 for dimethomorph, 1.95 and 2.09 for famoxadone, and 1.99 and 1.35 for cymoxanil at SD and DD, respectively. PF value >1 indicates concentration of the residues during raisin making. The residues of detected pesticides in market samples of raisins were devoid of any risk of acute toxicity related to dietary exposure.

Kinetics of degradation of carbendazim by B. subtilis strains: possibility of in situ detoxification.

Food safety is a global concern due to the increased use of pesticides in agriculture. In grapes, carbendazim is one of the frequently detected fungicides. However, it is amenable to biodegradation. In this study, we aimed to assess the degradation of carbendazim by four Bacillus subtilis strains, which had earlier shown potential for biocontrol of grape diseases. In liquid medium, each of the four strains, namely, DR-39, CS-126, TL-171, and TS-204, could utilize carbendazim as the sole carbon source. The half-life was minimized from 8.4 days in the uninoculated spiked control to 4.0-6.2 days by the four strains. In Thompson Seedless sprayed with carbendazim at 1.0 g L(-1), the residue on grape berries in control was 0.44 mg kg(-1) after 25 days of application, whereas in grapes treated with the four B. subtilis strains, the residues had decreased to 0.02 mg kg(-1). The degradation kinetics showed low half-lives of 3.1 to 5.2 days in treated grapes as compared to 8.8 days in control. In inoculated soils, the half-lives were 5.9 to 7.6 days in autoclaved and 6.5 to 7.2 days in nonautoclaved soils as compared to 8.2 and 8.0 days in respective controls. The growth dynamics of these strains in all the three matrices was not affected by presence of carbendazim. Bacillus strains TS-204 and TL-171 showed higher degradation rate than the other two strains in all the three matrices and show promise for in situ biodegradation of carbendazim.