Evaluation of multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS) for sulfur metabolic studies using 34S-labelled yeast

A multi-collector ICP-MS instrument was evaluated for the on-line measurement of sulfur isotope ratios during the liquid chromatographic separation of sulfur metabolites in mouse urine after the oral administration of 34 S-labelled yeast. The multi-collector instrument used was equipped with both Faraday cups and ion counters at positions L4 (32), C (33) and H4 (34). For the optimisation of the resolution, cup configuration and measurement conditions an artificial mixture of natural sulfur and highly enriched 33 S and 34 S was prepared. The results were compared with those obtained using a sector field single collector instrument from the same manufacturer. Both instruments provided good accuracy in the measurement of sulfur isotope ratios but better precision (