Determination of fungicide residues in white grapes for winemaking by gas chromatography with mass spectrometric detection and assessment of matrix effects.

A new analytical method, based on organic solvent extraction with dichloromethane-acetone (75 + 25, v/v) followed by gas chromatography with mass spectrometric detection, is presented for the determination of residues of 10 fungicides in white grapes for vinification. Some of them (cyprodinil, fludioxonil, and pyrimethanil) have been used for only 2-3 years and, therefore, no methods are available in the scientific literature for such a screening. Quality parameters yielded good precision (relative standard deviation of <10%) and detection limits (ranging between 1 and 18 microg/kg) that are lower than the maximum residue limits (MRLs) set by the 76/895/European Economic Community (EEC) and 90/642/EEC Directives.

Solid-phase microextraction-gas chromatographic-mass spectrometric method for the determination of the fungicides cyprodinil and fludioxonil in white wines.

A solid-phase microextraction (SPME) followed by a gas chromatographic-mass spectrometric (GC-MS) determination has been developed and validated for the determination of cyprodinil and fludioxonil in white wine samples. Extraction parameters such as the selection of SPME coating, the effect of the temperature, the effect of the headspace volume and the salt addition were studied and optimized, together with GC-MS analytical conditions. The divinylbenzene-Carboxen-polydimethylsiloxane (DVB-CAR-PDMS) fiber was the most appropriate for the determination of the two pesticides in wine.