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.

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.

Optimization of multi-residue method for targeted screening and quantitation of 243 pesticide residues in cardamom (Elettaria cardamomum) by gas chromatography tandem mass spectrometry (GC-MS/MS) analysis.

Higher matrix interference makes the multi-residue pesticide analysis in spices more challenging. A simple, sensitive, and robust large-scale multi-residue method was developed for the rapid analysis of 243 pesticides in cardamom matrix by gas chromatography tandem mass spectrometry (GC-MS/MS). Prehydration of cardamom in 1:4 sample:water for 30 min improved the homogeneity and extractability. QuEChERS extraction followed by cleanup with 25 mg primary secondary amine, 100 mg C18, and 10 mg graphitized carbon black to 1 ml supernatant was used for sample preparation. Reconstitution of final extract in ethyl acetate reduced matrix co-extract up to 60%. The method was validated according to the SANTE/11,945/2015 guidelines. The limit of quantification was ≤0.01 mg kg-1, and the recovery was within 70.0-120.0%, with ≤20% RSD for the majority of pesticides. The method was used for screening market samples, and the detected residues were devoid of any risk of acute toxicity related to dietary exposure.

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.

Rapid and sensitive multiresidue analysis of pesticides in tobacco using low pressure and traditional gas chromatography tandem mass spectrometry.

Public exposure to pesticide residues through the main/side-stream smoke of tobacco (Nicotiana tabacum L.) is an international concern. This article reports optimization and validation of large-scale multiresidue analysis methods involving low pressure and traditional gas chromatography tandem mass spectrometry in compliance with the guidance residue levels (GRLs) of Cooperative Centre for Scientific Research Relative to Tobacco (CORESTA). Analysis by low pressure GC-MS/MS offered three times rapid turn around time over the traditional GC-MS/MS with limits of quantifications (LOQs) less than 2µg/L for all the 259 test compounds and the recoveries in the range of 70-118% (±20%) at 10 and 20µg/kg levels of fortification.

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.

Optimization of a sample preparation method for multiresidue analysis of pesticides in tobacco by single and multi-dimensional gas chromatography-mass spectrometry.

A selective and sensitive multiresidue analysis method, comprising 4 7pesticides, was developed and validated in tobacco matrix. The optimized sample preparation procedure in combination with gas chromatography mass spectrometry in selected-ion-monitoring (GC-MS/SIM) mode offered limits of detection (LOD) and quantification (LOQ) in the range of 3-5 and 7.5-15ng/g, respectively, with recoveries between 70 and 119% at 50-100ng/g fortifications. In comparison to the modified QuEChERS (Quick-Easy-Cheap-Effective-Rugged-Safe method: 2g tobacco+10ml water+10ml acetonitrile, 30min vortexing, followed by dispersive solid phase extraction cleanup), the method performed better in minimizing matrix co-extractives e.g. nicotine and megastigmatrienone. Ambiguity in analysis due to co-elution of target analytes (e.g. transfluthrin-heptachlor) and with matrix co-extractives (e.g. δ-HCH-neophytadiene, 2,4-DDE-linolenic acid) could be resolved by selective multi-dimensional (MD)GC heart-cuts. The method holds promise in routine analysis owing to noticeable efficiency of 27 samples/person/day.