Determination of rare earth elements in wine by inductively coupled plasma mass spectrometry using a microconcentric nebulizer

A method for the direct determination of REEs in undiluted wine by ICP-MS was developed. The performance of a microconcentric nebulizer (MCN) was optimized regarding the nebulizer gas how rate and sample uptake rate for all the REEs in terms of signal intensity and signal-to-noise ratio. The effect of ethanol on the sensitivity was also studied Possible spectral interferences were identified and are discussed in detail. The MCN was shown to reduce the sample consumption to 30-50 mu l min(-1) and to decrease the matrix signal suppression by a factor of 2-5 in comparison with a de Galan nebulizer. Polyatomic interferences were found to be negligible except for those of BaO on Eu-151, Eu-153 and Gd-155 and of (LaO)-La-139-O-16 on Gd-155. Data obtained with three different ICP-RIS instruments were compared. Several wines from different vineyards in France, California and Australia were analysed for REEs. The REE concentration patterns showed inter-continental and inter-regional variations, whereas no difference was observed for different vintages from the same vineyard over a period of several years.