DETERMINATION OF RHENIUM WITH ENHANCED SENSITIVITY USING INDUCTIVELY COUPLED PLASMA MASS-SPECTROMETRY

A vapour generation - merging sample introduction system for inductively coupled plasma mass spectrometry (ICP-MS) has been developed for the determination of picogram amounts of Re. Sample solution and oxidising agent were introduced into a heating cell placed in a merging chamber, which was followed by a drying stage, then vaporised Re2O7 was carried to the ICP with blank aerosol sprayed from the nebuliser. With the adoption of a flow system designed specifically for sample loading, good reproducibility of signal intensity could be obtained for picrogram amounts of Re. The effects of cell temperature and volume of oxidising solution on the signal intensity were investigated in detail. Using isotope dilution mass spectrometry, the Re abundances of four meteoritic samples were determined. The precision of the abundance measurements using 3 ng of Re was ca. 1%. The absolute detection limit for Re by this technique was 10 fg (3σ), which is almost 25 times less than that obtained by a conventional nebulisation sample introduction technique.