ANALYSIS OF METALAXYL RESIDUES IN WINES BY SPE IN COMBINATION WITH HRCGC AND GC MS/

Solid phase extraction (SPE) with the porous carbon sorbent CARB GR wa s used for the preconcentration of metalaxyl residues from a variety o f Slovak grape wines with subsequent capillary GC and GC/MS analysis. Recovery was tested al various concentrations of metalaxyl in standard solutions (recovery, R greater than or equal to 92%, relative standar d deviation RSD less than or equal to 4.3%) and in wines. The value of recovery in spiked wines was dependent on the concentration (studied in the range 0.02-1.96 mg/l) and on the variety of wine (R = 80-99% RS D = 2-7%). Limits of quantitation (for a sample volume of 50 ml) were determined to be 0.75 mu g/l with GC-FID and 0.50 mu g/l with GC/MS-IT D. Concentration levels of metalaxyl residues were determined in treat ed wines (with 0.25% Ridomil plus 48 WP) and a strong dependence on th e protective term before the harvest was shown.