Analysis of Pyrimethanil, Metalaxyl, Dichlofluanid, and Penconazol in Must and Wine from Red Grapes by Solid-Phase Extraction and Gas Chromatography

Abstract

This article describes a method for the simultaneous analysis of four fungicides—pyrimethanil, penconazol, metalaxyl, and dichlofluanid—in must and wine by solid-phase extraction. Two cartridges (octadecylsilane and polystyrene-divinylbenzene) were evaluated with different elution solvents. The most efficient solid phase was octadecylsilane together with ethyl acetate as elution solvent. Determination was performed by gas chromatography with a nitrogen–phosphorus detector, using metribuzin as internal quantification standard. To reduce quantitative errors from matrix effects, matrix-matched calibration was used. The linear regression coefficients were at least 0.9990. The quality parameters of the proposed method presented good recoveries from spiked must and wine, ranging from 92.3 to 105.5%, and good precision, indicated by relative standard deviations (RSDs) of less than 10%. The limits of quantification varied from 0.27 µg L−1 for penconazol in wine to 9.34 µg L−1 for metalaxyl in wine. An additional confirmation method, gas chromatography with mass spectrometry detection, was used.