Published: June 14, 2011 r2011 American Chemical Society 7866 dx.doi.org/10.1021/jf200525d | J. Agric. Food Chem. 2011, 59, 7866–7873 ARTICLE pubs.acs.org/JAFC Dissipation and Distribution Behavior of Azoxystrobin, Carbendazim, and Difenoconazole in Pomegranate Fruits Sagar C. Utture, †,‡,§ Kaushik Banerjee,* ,†,§ Soma Dasgupta, †,§ Sangram H. Patil, †,‡,§ Manjusha R. Jadhav, †,§ Sameer S. Wagh, †,§ Sanjay S. Kolekar, ‡,§ Mansing A. Anuse, ‡ and Pandurang G. Adsule † † National Referral Laboratory, National Research Centre for Grapes, P.O. Manjri Farm, Pune-412 307, India ‡ Department of Agrochemicals and Pest Management, Shivaji University, Kolhapur-416 004, India b S Supporting Information ABSTRACT: The dissipation behavior and degradation kinetics of azoxystrobin, carbendazim, and difenoconazole in pomegranate are reported. Twenty fruits/hectare (5 kg) were collected at random, ensuring sample-to-sample relative standard deviation (RSD) within 2025%. Each fruit was cut into eight equal portions, and two diagonal pieces per fruit were drawn and combined to constitute the laboratory sample, resulting in RSDs <6% (n = 6). Crushed sample (15 g) was extracted with 10 mL of ethyl acetate (+ 10 g Na 2 SO 4 ), cleaned by dispersive solid phase extraction on primary secondary amine (25 mg) and C 18 (25 mg), and measured by liquid chromatography tandem mass spectrometry. The limit of quantification was e0.0025 μgg 1 for all the three fungicides, with calibration linearity in the concentration range of 0.0010.025 μg mL 1 (r 2 g 0.999). The recoveries of each chemical were 75110% at 0.0025, 0.005, and 0.010 μgg 1 with intralaboratory Horwitz ratio <0.32 at 0.0025 μgg 1 . Variable matrix effects were recorded in different fruit parts viz rind, albedo, membrane, and arils, which could be correlated to their biochemical constituents as evidenced from accurate mass measurements on a Q-ToF LC-MS. The residues of carbendazim and difenoconazole were confined within the outer rind of pomegranate; however, azoxystrobin penetrated into the inner fruit parts. The dissipation of azoxystrobin, carbendazim, and difenoconazole followed first + first order kinetics at both standard and double doses, with preharvest intervals being 9, 60, and 26 days at standard dose. At double dose, the preharvest intervals extended to 20.5, 100, and 60 days, respectively. KEYWORDS: fungicides, azoxystrobin, carbendazim, difenoconazole, pomegranate, residues, method validation, dissipation, preharvest interval (PHI) ’ INTRODUCTION Pomegranate is an important tropical fruit crop extensively cultivated in India in an area of around 0.1 million ha with an export value of INR 92 million. 1 The incidence of fungal diseases, e.g. wilt caused by Fusarium oxysporum, Rhizoctonia solani, Ceratocystis fimbriata, leaf and fruit spots caused by Cercospora punicae, Colletotrichum gloeosporioides, Alternaria alternata, and fruit rot caused by Rhizopus sp. and Colletotrichum spp., 2 is one of the major causes of economic loss in pomegranate production, which necessitates regular application of fungicides 3 to secure desired yield and fruit quality for domestic sales as well as to promote export. From a preliminary survey of pomegranate farms, carbendazim (methyl benzimidazole-2-ylcarbamate), di- fenoconazole (3-chloro-4-[(2RS,4RS;2RS,4SR)-4-methyl-2-(1H-1, 2,4-triazol-1-ylmethyl)-1,3-dioxolan-2-yl] phenyl 4-chlorophe- nyl ether), and azoxystrobin (methyl (2E)-2-{2-[6-(2-cyano- phenoxy) pyrimidin-4-yloxy] phenyl}-3-methoxyacrylate) were identified to have strong potential for the management of various fungal diseases of pomegranate. Carbendazim is a traditionally used fungicide, whereas the other two are relatively new entries in Indian horticulture. Literature survey reflects nonavailability of residue dissipation data for either of these fungicides in pome- granate as per the good agricultural practices, which creates apprehension of accumulation of their residues at levels above the maximum residue limits (MRLs) at the stage of harvest, 4 resulting in food safety restriction issues. Pomegranate fruit is characterized by a thick outer rind that encloses the soft and edible aril. Because of this typical nature of pomegranate fruits, the residue dynamics information generated for other fruits may not be applicable to it. In our earlier studies in grapes, the residues of carbendazim were reported to dissipate following first-order rate kinetics, 5 while the dissipation of difenoconazole followed first + first order rate kinetics. 6 The residues of thiabendazole and imazalil were identified to get mostly localized in the peel of the orange fruits, with a small fraction of imazalil being translocated into the pulp. 7 Teixeira et al. investigated the levels of 13 fungicides and one insecticide in grapes and concluded that there were no significant differences between the pesticide levels in the whole grape berry (skin and pulp) and the berry skin for most of the test chemicals, with exception of Pyrimethanil, the residues of which was accumu- lated in pulp. 8 Such kind of information regarding fractionation of pesticide residues among different fruit parts of pomegranate is not available in literature, which could be the reason why the whole pomegranate fruits are considered for residue analysis despite the fact that the rind portion is nonedible to human beings. Received: February 7, 2011 Accepted: June 14, 2011 Revised: June 7, 2011