DETERMINATION OF LEAD IN WINE BY THE FIAS -FAAS COMBINATION ONLINE PRECONCENTRATION SYSTEM

A flow-injection on-line preconcentration and seperation procedure for flame-AAS with a microwave digestion system is described for the dete rmination of lead at mu g/L levels in wine, The sorbent extraction pre concentration system is a micro-column (50 mu L) with bonded silica gr oups C18 as the sorbent and DDC as the complexing agent. The wine samp les were digested using hydrogen peroxide as a digestion oxidizer in t he microwave digestion system, An enrichment factor of 100 and a detec tion limit (3 sigma) of 3.0 mu g/L were thereby obtained. The sample t hroughput was 33/h for a sample loading time of 90 s with RSD 1.8%(n=1 ). The recoveries of lead added in wine were 95%similar to 103%.