Determination of trace metals and pesticides in must during fermentation in a vinification process.

摘要

Selected trace metals (Cu, Pb and Zn), an ultra-trace metal (Cd), and pesticides (metalaxyl, penconazole, procymidone and parathion) were determined during the fermentation step in a vinification process. 2 laboratory-scale fermentations were carried out, with and without skins (for production of red and white wine, respectively), and each day samples of must were collected and analysed. Levels of metals were determined by 2 analytical techniques: inductively coupled plasma MS (ICP-MS) and stripping voltammetry (SV) with a thick-film modified graphite-containing electrode. For analysis of the pesticides, a liquid-liquid extraction and silica gel clean-up followed by GC-MS detection was used. Cu and Zn concn. decreased in a continuous manner throughout the 2 winemaking processes, while Pb and Cd concn. dropped sharply during the first 2 days and stabilized afterwards. The reduction in pesticide concn. was more evident with the red wine vs. the white wine vinification process. Parathion levels decreased quite rapidly, while metalaxyl was the most persistent.