Determination of rare earth elements in wine by inductively coupled plasma mass spectrometry using a microconcentric nebulizer
Résumé
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 flow 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 ?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 151Eu, 153Eu and 155Gd and of 139La16O on 155Gd. Data obtained with three different ICP-MS 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.