Determination of pesticide residues in wine using gas chromatography with nitrogen-phosphorus and electron capture detection.

A multiresidue method employing an extraction step with ethyl acetate followed by clean-up using an Isolute silica column and determination using gas chromatography with nitrogen-phosphorus and electron capture detection was validated for a wide range of pesticide residues in white and red wine. Recoveries between 70 and 110% and relative standard deviations below 20% were obtained for nearly all target analytes using matrix-matched standards. Limits of detection based on three times the signal-to-noise ratio were in the range 0.002-0.01 mg l(-1) for most compounds. The chromatograms were generally free of interference peaks resulting from co-extractives, although a few were noted for red wine with nitrogen-phosphorus detection. Ninety-two wine samples collected in Greece and Yugoslavia during 2 consecutive years were screened for residues of 84 pesticides, 71% of which were registered for use on vines in one or both countries. A total of 20% of the samples were obtained from field trials, and of these, one Greek wine contained iprodione 0.3 mg l(-1) and six Yugoslavian wines, for which vinclozolin had been added to the must as part of a different study, contained residues of this pesticide. No residues were detected in any of the other samples.