Quality assurance
To verify the analytical data obtained by PSA, some of the wine samples were digested by HPA and analyzed by anodic stripping voltammetry. For lead, it was also possible to check the data by ET-AAS. Table 2 presents some results which were obtained.
For the three elements, good agreement of the PSA data with the values found by other analytical techniques was observed.
The proposed PSA procedure can therefore be used for the routine determination of Cd, Pb and Cu in wine samples in connection with sample changer.
Element distribution
To generate information about the “normal” levels of Cd, Pb and Cu in German wine, about 150 wine samples from different regions of Germany were analyzed by the proposed PSA method. Figure 6 presents the concentration distribution of cadmium, lead and copper in German wine samples from 1993/94. In 84% of wines samples, the cadmium concentration was lower than 0.4 ng/mL while in 96% of wine samples, the lead concentration was lower than 150 ng/mL.
The copper concentration was, in 84% of wine samples, lower than 500 ng/mL.