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Dasgupta S.,University of Pune | Banerjee K.,National Research Center for Grapes | Dhumal K.N.,University of Pune | Adsule P.G.,National Research Center for Grapes
Journal of AOAC International | Year: 2011

This paper describes single-laboratory validation of a multiresidue method for the determination of 135 pesticides, 12 dioxin-like polychlorinated biphenyls, 12 polyaromatic hydrocarbons, and bisphenol A in grapes and wine by GC/time-of-flight MS in a total run time of 48 min. The method is based on extraction with ethyl acetate in a sample-to-solvent ratio of 1:1, followed by selective dispersive SPE cleanup for grapes and wine. The GC/MS conditions were optimized for the chromatographic separation and to achieve highest S/N for all 160 target analytes, including the temperature-sensitive compounds, like captan and captafol, that are prone to degradation during analysis. An average recovery of 80-120% with RSD <10% could be attained for all analytes except 17, for which the average recoveries were 70-80%. LOQ ranged within 10-50 ng/g, with <25% expanded uncertainties, for 155 compounds in grapes and 151 in wine. In the incurred grape and wine samples, the residues of buprofezin, chlorpyriphos, metalaxyl, and myclobutanil were detected, with an RSD of <5% (n = 6); the results were statistically similar to previously reported validated methods.

Khar A.,Directorate of Onion and Garlic Research ICAR | Banerjee K.,National Research Center for Grapes | Jadhav M.R.,National Research Center for Grapes | Lawande K.E.,Directorate of Onion and Garlic Research ICAR
Food Chemistry | Year: 2011

An aqueous extraction method coupled with ultra performance liquid chromatography with photo diode array detection was optimised and validated for screening of 93 garlic ecotypes for allicin and other allyl thiosulphinate contents. Variability in allicin, allyl methyl thiosulphinate and allyl trans-1-propenyl thiosulphinate was observed both on fresh and dry weight basis. Bulb to bulb variation for allicin levels was less in clonal selections followed by commercial varieties, exotic line and landraces, respectively. Five ecotypes on fresh weight basis and all the ecotypes on dry weight basis had allicin contents more than the recommended pharmacological values (≥4.5 mg g-1). Cluster analysis and principal component analysis results revealed that geographical origin, breeding status and colour did not play any role in ecotype clustering. This study is useful as a base for selection of garlic ecotypes as a dependable raw material source for pharmaceutical and food processing industries. © 2011 Elsevier Ltd. All rights reserved.

Oulkar D.P.,National Research Center for Grapes | Banerjee K.,National Research Center for Grapes | Kulkarni S.,Agilent Technologies
Journal of AOAC International | Year: 2011

A selective and sensitive LC-MS/MS method is presented for simultaneous determination of 12 plant growth regulators, viz., indol- 3-acetic acid, indol-3-butyric acid, kinetin, zeatin, 6-benzyl aminopurine, gibberellic acid, abscisic acid, chlormequat chloride, forchlorfenuron, paclobutrazole, daminozide, and 2,4-dichlorophenoxy acetic acid, in bud sprouts and grape berries. The sample preparation method involved extraction of homogenized sample (5 g) with 40 mL methanol (80%), and final determination was by LC-MS/MS in the multiple reaction monitoring (MRM) mode with time segmentation for quantification supported by complementary analysis by quadrupole-time of flight (Q-TOF) MS with targeted high-resolution MS/MS scanning for confirmatory identification based on accurate mass measurements. The recovery of the test compounds ranged within 90-107% with precision RSD less than 5% (n = 6). The method could be successfully applied in analyzing incurred residue samples, and the strength of accurate mass analysis could be utilized in identifying the compounds in cases where the qualifier MRM ions were absent or at an S/N less than 3:1 due to low concentrations. © 2012 Publishing Technology.

Fontana A.R.,CONICET | Patil S.H.,National Research Center for Grapes | Banerjee K.,National Research Center for Grapes | Altamirano J.C.,CONICET | Altamirano J.C.,National University of Cuyo
Journal of Agricultural and Food Chemistry | Year: 2010

A fast and effective microextraction technique is proposed for preconcentration of 2,4,6-trichloroanisole (2,4,6-TCA) from wine samples prior gas chromatography tandem mass spectrometric (GC-MS/MS) analysis. The proposed technique is based on ultrasonication (US) for favoring the emulsification phenomenon during the extraction stage. Several variables influencing the relative response of the target analyte were studied and optimized. Under optimal experimental conditions, 2,4,6-TCA was quantitatively extracted achieving enhancement factors (EF) ≥ 400 and limits of detection (LODs) 0.6-0.7 ng L -1 with relative standard deviations (RSDs) -11.3%, when 10 ng L -1 2,4,6-TCA standard-wine sample blend was analyzed. The calibration graphs for white and red wine were linear within the range of 5-1000 ng L -1, and estimation coefficients (r 2) were ≥0.9995. Validation of the methodology was carried out by standard addition method at two concentrations (10 and 50 ng L -1) achieving recoveries >80% indicating satisfactory robustness of the method. The methodology was successfully applied for determination of 2,4,6-TCA in different wine samples. © 2010 American Chemical Society.

Mujawar S.,National Research Center for Grapes | Utture S.C.,National Research Center for Grapes | Fonseca E.,University of Costa Rica | Matarrita J.,University of Costa Rica | Banerjee K.,National Research Center for Grapes
Food Chemistry | Year: 2014

A sensitive and rugged residue analysis method was validated for the estimation of dithiocarbamate fungicides in a variety of fruit and vegetable matrices. The sample preparation method involved reaction of dithiocarbamates with Tin(II) chloride in aqueous HCl. The CS2 produced was absorbed into an isooctane layer and estimated by GC-MS selected ion monitoring. Limit of quantification (LOQ) was ≤40 μg kg-1 for grape, green chilli, tomato, potato, brinjal, pineapple and chayote and the recoveries were within 75-104% (RSD < 15% at LOQ). The method could be satisfactorily applied for analysis of real world samples. Dissipation of mancozeb, the most-used dithiocarbamate fungicide, in field followed first + first order kinetics with pre-harvest intervals of 2 and 4 days in brinjal, 7 and 10 days in grapes and 0 day in chilli at single and double dose of agricultural applications. Cooking practices were effective for removal of mancozeb residues from vegetables. © 2013 Elsevier Ltd. All rights reserved.

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