A SIMPLE METHOD FOR THE DETERMINATION OF LEAD IN WINE USING ZEEMAN ELECTROTHERMAL ATOMIZATION ATOMIC-ABSORPTION SPECTROMETRY

A simple method for the determination of lead in wine by electrotherma l atomization AAS is described. Lead is measured following a simple 1: 4 dilution of wine samples with a chemical modifier solution containin g 0.25% HNO3, 0.25% NH4H2PO4, and 0.0125% Mg(NO3)2. Instrument calibra tion is carried out using six Pb standard solutions that are matrix-ma tched for ethanol content. The peak appearance times for Pb in standar ds and wine samples are similar, thus permitting calibration with matr ix-matched aqueous Pb standards, Using the optimized furnace condition s, the characteristic mass (m0) is 41.7 pg (expected mo = 33 pg). Over all Precision is good (RSD less-than-or-equal-to 5.0%) and the minimum detection limit (3sigma) for Pb in wine is 6.2 mug/L. The accuracy of the method is assessed through participation in an interlaboratory co mparison of methods for the determination of Pb in wine organized join tly by the European Community's Bureau of Community Reference (BCR) an d the U.S. Food and Drug Administration (FDA). The certified values ar e within the confidence limits reported with results obtained using th is method. Results of analysis of several American and European wines are reported. The concentrations of Pb in wines tested were relatively low compared with the European recommended limit of 300 mug/L for Pb in wine, although some New York State and European wines approached or exceeded a proposed U.S. limit of 50 mug/L.