High-resolution MC-ICPMS employing amplifiers with a 10 ¹² ohm resistor for bulk sulfur determination in biological and geological samples

The analytical performance of high-resolution multiple-collector inductively coupled plasma mass spectrometry (HR-MC-ICPMS), employing amplifiers with a 10 ¹² ohm resistor, was examined. HR-MC-ICPMS showed 50 times higher detection efficiency and 100 times better precision for sulfur and ³⁴S/ ³²S than the single-collector high-resolution sector field type ICPMS (HR-ICP-SFMS). The 3σ detection limits for ³²S and ³⁴S were 0.2 and 6 ng mL ^-1, respectively. No matrix effects were observed, for up to 3000 μg g ^-1 of total dissolved solids (TDS), within 0.6% error. Thus when the isotope dilution (ID) technique is utilized, this method allows analyses of sulfur concentration of seven times smaller, with six times better precision, than the HR-ICP-SFMS methods. To demonstrate the applicability of this ID-HR-MC-ICPMS method, bulk sulfur concentrations in bovine serum albumin, human serum, eight silicate reference materials (JB-2, JB-3, JA-2, JA-3, JP-1, BCR-2, BHVO-1 and AGV-1), and four carbonaceous chondrites (Murchison, Allende, Dal al Gani 521 and 194) were measured.