PIXE determination of Pb in wine

Abstract The permissible level of the Pb content in wine varies in the range of 200–300 μg/l in different countries. These values are below the detection limit for standard PIXE spectrometry. Initiated by an intercomparison action of The International Measurement Evaluation Programme (IMEP, Geel, Belgium), an attempt was made to lower the detection limit of PIXE without introducing any additional chemical steps. Wine samples of 5 ml were gradually condensed below an infrared lamp and 8 μl aliquots were taken from time to time and pipetted onto filter paper. The samples were analysed by standard PIXE technique, with the analyte addition method used for calibration. A detection limit of about 50 ppb was finally achieved. Comparing this value to the permissible levels, this simple and fast technique can be used for screening purposes. As an application, the lead content of three Hungarian market wines was also measured.