Simultaneous determination of imidacloprid, carbendazim, methiocarb and hexythiazox in peaches and nectarines by liquid chromatography-mass spectrometry

A liquid chromatographic (LC) atmospheric pressure chemical ionization mass spectrometric (MS) method is described for determining imidacloprid, carbendazim, methiocarb and hexythiazox in peaches and nectarines. The samples were extracted with ethyl acetate and anhydrous sodium sulfate. Recoveries yield for spiking samples were ranged from 64 +/- 9% (R.S.D) for carbendazim to 108 +/- 14% (R.S.D.) for hexythiazox at the concentration of 0.1 mg kg(-1) (n = 5). The correlation coefficients were greater than 0.998 over the range between 0.02 and 2 mg kg(-1). The limits of quantitation (LOQ) were 0.02 mg kg(-1) for all the pesticides. The applicability of the method to detect and quantify imidacloprid, carbendazim, methiocarb and hexythiazox was demonstrated successfully in 159 peach and nectarine samples obtained from an agricultural co-operative. The calculation of the estimated daily intakes (EDI) from these data showed that contribution of fruits to dietary intakes were much lower than acceptable daily intakes (ADI) proposed by international agencies. (C) 2002 Elsevier Science B.V. All rights reserved.