Multiresidue analysis of seventeen pesticides in wine by gas chromatography with mass-selective detection

We have developed a multiresidue method permitting the simultaneous quantit ation of 17 pesticides in wine: dicloran, dimethoate, diazinon, chlorpyrifo s-methyl, vinclozolin, carbaryl, methiocarb, dichlofluanid, parathion-ethyl , triadimefon, procymidone, myclobutanil, iprodione, imidan, dicofol, phosa lone and azinphos-methyl. Solid-phase extraction of 0.5 ml of wine sample i s followed by direct injection of 1 mu l of the eluent onto a DB-5 MS gas c hromatographic column followed by mass-selective detection using one target and two qualifier ions for each pesticide. The extraction and injection st eps are carried out with automatic instrumentation. Good resolution of all compounds was achieved with a run-time approximating 23 min. Detection and quantitation limits were around 2 mu g/l and 10 mu g/l, respectively, with linear calibration curves up to 3 mg/l for most constituents. Recovery in h alf the compounds was >90%, and >80% in most of the remainder. Imprecision (relative standard deviation) was <10% for most pesticides and <18% in all. Further analytes can be added to the repertoire without difficulty. The me thod merits consideration together with four other multiresidue methods now available that offer similar analytical characteristics, slower run-times, and a different selection of analytes. (C) 2000 Elsevier Science B.V. All rights reserved.