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The article analyzes the degradation kinetics and safety evaluation of residues of buprofezin in grapes and three types of soils of India. It aims at assessing the preharvest interval (PHI) of buprofezin to reduce its residues in grapes and ensure consumer safety. In the study, it was observed that PHI produced the desired result by minimizing buprofezin residues in grapes. As stated, this conclusion can be beneficial to the domestic and export grape industry in India as it complies with the standards of international trade.

Highlights: [•] Dissipation kinetics of the residues of CPPU, 6-BA, GA3 and Ethephon in grape are reported. [•] Dissipation of residues followed 1st +1st order kinetics. [•] Initial residue of GA3 was below MRL and hence no pre-harvest interval (PHI) is applicable. [•] CPPU, 6-BA and Ethephon residues dissipated with PHIs of 33.5, 12 and 32days, respectively. [Copyright &y& Elsevier]

Abstract: Food safety aspects of buprofezin, dimethoate and imidacloprid residues in pomegranate are reported. The residue analysis involved extraction of samples (15g) with 10ml ethyl acetate, cleanup by dispersive solid phase extraction with 25mg primary secondary amine and 25mg C18 sorbents and estimation by LC–MS/MS. The limit of quantification of each analyte was 0.001mgkg−1 with recoveries within 76–109%. The residues of buprofezin and dimethoate were confined to outer rind, which degraded to below the maximum residue limit for the European Union (EU-MRL) after 10.5 and 31.5days at standard dose and 32.0 and 44.0days at double dose. Residues of imidacloprid penetrated into the albedo and membrane, although at less than the MRL in all samples even at double dose. The dietary exposure of buprofezin and imidacloprid was safe on all sampling days; whereas samples with dimethoate appeared safe after 15 and 30days of field applications at standard and double doses, respectively. [Copyright &y& Elsevier]

Abstract: Water based samples such as flavored drinks, juices and drinking water may contain contaminants at ultra trace level belonging to different chemical classes. A novel, simple, low-cost and fast method was developed and validated for trace residue extraction of pesticides, dioxin-like PCBs and PAHs from water and water based samples followed by analysis through gas chromatography (GC) coupled with time-of-flight mass spectrometry (ToFMS). The extraction solvent type, volume; sample volume and other extraction conditions were optimized. This was achieved by extracting 10mL sample with 250μL chloroform by vortexing (1min, standing time of 2min) followed by centrifugation (6000rpm, 5min). The bottom organic layer (200μL) was pipetted out, evaporated to near dryness and reconstituted in 20μL of ethyl acetate+cyclohexane (1:9) mixture resulting in an enrichment factor of 400. The recoveries of all compounds were within 76–120% (±10%) with the method detection limit (MDL) ranging from 1 to 250ng/L depending on the analyte response. The MDLs were 400 times lower than the instrument quantification limits that ranged from 0.4 to 100ng/mL. The method was further validated in water based drinks (e.g. apple, lemon, pineapple, orange, grape and pomegranate juice). For the juices with suspended pulp, the extraction was carried out with 400μL chloroform. The extract was analyzed by GC-ToFMS at both 1D and GC×GC modes to chromatographically separate closely eluting interfering compounds the effect of which could not be minimized otherwise. The resulting peak table was filtered to identify a range of compounds belonging to specific classes viz. polycyclic aromatic hydrocarbons, chlorinated, brominated, and nitro compounds. User developed scripts were employed on the basis of identification of the molecular ion and isotope clusters or other spectral characteristics. The method performed satisfactorily in analyzing both incurred as well as market samples. [Copyright &y& Elsevier]

Abstract: A novel method for the residue analysis of wine spoilage compound 2,4,6-trichloroanisole is reported. Wine (60ml) was extracted with 2ml toluene in presence of 24g MgSO4 and 6g NaCl. Cleanup of the toluene phase by dispersive solid phase extraction with mixture of 100mg CaCl2, 25mg primary secondary amine and 50mg MgSO4 was effective in minimising co-extractives and matrix effects. Time-of-flight and tandem mass spectrometric parameters were optimised to achieve linearity over 0.25–500ngml−1 and method detection limit 0.0083ngml−1 which is well below the odour threshold of 0.04ngml−1. Recoveries at 0.04, 0.2 and 0.8ngml−1 were within 80–110% (±8%). The method was reproducible when tested for Argentinean wines with intra-laboratory Horwitz ratios being <0.20 in white and red wines at both the laboratories of India and Argentina. The method could be successfully applied for incurred wine samples. [ABSTRACT FROM AUTHOR]

Abstract: Two-dimensional gas chromatography (GC×GC) coupled with time-of-flight mass spectrometric (TOFMS) method was optimized for simultaneous analysis of 160 pesticides, 12 dioxin-like polychlorinated biphenyls (PCBs), 12 polyaromatic hydrocarbons (PAHs) and bisphenol A in grape and wine. GC×GC–TOFMS could separate all the 185 analytes within 38min with >85% NIST library-based mass spectral confirmations. The matrix effect quantified as the ratio of the slope of matrix-matched to solvent calibrations was within 0.5–1.5 for most analytes. LOQ of most of the analytes was ≤10μg/L with nine exceptions having LOQs of 12.5–25μg/L. Recoveries ranged between 70 and 120% with <20% expanded uncertainties for 151 and 148 compounds in grape and wine, respectively, with intra-laboratory Horwitz ratio <0.2 for all analytes. The method was evaluated in the incurred grape samples where residues of cypermethrin, permethrin, chlorpyriphos, metalaxyl and etophenprox were detected at below MRL. [Copyright &y& Elsevier]

Abstract: A multiresidue method is described for simultaneous estimation of 83 pesticides and 12 dioxin-like polychlorinated biphenyls (PCBs) in red and white wines. The samples (20mL wine, acidified with 20mL 1% HCl) were extracted with 10mL ethyl acetate (+20g sodium sulphate) and cleaned by dispersive solid-phase extraction (DSPE) with anhydrous calcium chloride and Florisil successively. The final extract (5mL) was solvent exchanged to 1mL of cyclohexane:ethyl acetate (9:1), further cleaned by DSPE with 25mg primary secondary amine sorbent and analyzed by gas chromatography–time-of-flight mass spectrometry (GC–TOF-MS) within 31min run time. The limits of quantification of most analytes were ≤10–20μg/L. Acidification of wine prior to extraction prevented hydrolysis of organophosphorous pesticides as well as dicofol, whereas treatment with CaCl2 minimized the fatty acid co-extractives significantly. Solvent exchange to cyclohexane:ethyl acetate (9:1) further minimized the co-extractives. Recoveries at 5, 10 and 20ng/mL were >80% for most analytes except cyprodinil, buprofezin and iprodione. The expanded uncertainties at 10ng/mL were <20% for most analytes. Intra-laboratory precision in terms of Horwitz ratio of all the analytes was below 0.5, suggesting ruggedness of the method. Effectively, the method detection limit for most analytes was as low as up to 1ng/mL in both red and white wine, except for cyfluthrin and cypermethrin. [Copyright &y& Elsevier]

Abstract: A method was validated for the multi-residue analysis of 82 pesticides in grapes at ≤25ng/g level. Berry samples (10g) mixed with sodium sulphate (10g) were extracted with ethyl acetate (10mL); cleaned by dispersive solid phase extraction and the results were obtained by liquid chromatography–tandem mass spectrometry. Reduction in sample size and proportion of ethyl acetate for extraction did not affect accuracy or precision of analysis when compared to the reported methods and was also statistically similar to the QuEChERS technique. The method was rugged (HorRat<0.5) with <20% measurement uncertainties. Limit of quantification was <10ng/g with recoveries 70–120% for most pesticides. The method offers cheaper and safer alternative to typical multi-residue analysis methods for grape. [Copyright &y& Elsevier]