Determination of lead isotope ratios in clinopyroxene by inductively coupled plasma mass spectrometry applying solution nebulization or laser ablation sample introduction techniques

Abstract

Lead isotope ratios were determined in clinopyroxene originating from Hungary and in a Japanese basalt standard (JB-2) by a single-collector inductively coupled plasma sector field mass spectrometer applying solution nebulization and laser ablation (LA) as sample introduction techniques. The solutions were prepared by dissolution of samples in a mixture of HF/HNO3 and isolation of analyte by Pb-selective crown ether resin. The separation of Pb from the matrix and other compounds lowered the contribution of the major interference (204Hg) to the counts of 204Pb to less than 1%. More than 94.5% and 98.4% of the Pb content of the clinopyroxene and JB-2 samples, respectively, could be collected on the resin. The relative standard deviations of the measured Pb isotope ratios obtained by solution technique changed between 0.3% and 0.5%. In the case of LA with repetition rate of 10 Hz and spot size of 100 µm these values were between 1.3% and 1.6%.