Accurate determination of lead in wines by inductively coupled plasma mass spectrometry

The capability of inductively coupled plasma mass spectrometry (ICP-MS) for Pb determination in wine samples is studied. An evaluation is made of the signal behaviour in aqueous ethanolic medium. The effect of preliminary sample preparation on signal suppression or enhancement is investigated in conjunction with the ability of internal standardization to correct for it. As a result, an accurate and precise method of analysis is described in which the sample preparation is limited to a 10-fold dilution and external calibration is applied for quantitation. A detection limit of 0.2 mig 1(-1) Pb in wine is achieved. The Pb content of ten different wines was found to range around 40 mig 1(-1) with extreme values of 1.63 and 58.8 mig 1(-1).