Study of heavy metals in Madeira wine by total reflection X-ray fluorescence analysis

The suitability and high sensitivity of total-reflection x-ray fluorescence analysis (TXRF) were used for multi-element analysis of several species of Madeira wine taken directly from the usual glass bottles. In addition, the uptake of lead by Madeira wine kept in a crystal vessel (30% lead) as a function of time was also studied. The detection limits were in the range 0.001–0.10 mg 1−1 and the precision was in the range 5–10%. The organic matrix of the wine was removed by wet digestion in nitric acid.