Abstract:
This study reported a measurement method of high-precision rhenium isotope ratio,
187Re/
185Re, and Re concentration of natural rock samples were measured by multi-collector inductively coupled plasma mass spectrometry (MC-ICPMS) through measuring the amount of fractionation on admixed lridium. It recognizes that the mass fractionation of MC-ICPMS appears to follow the exponential law, and the fractionation coefficients of Re and Ir are not identical, but the ratio of
fRe/
fIr is constant during an analytical session. Thus, this constant ratio can be used to calculate the value of
fRe according to known value
fIr. Replicate analyses of both Re natural standard and
185Re enriched spike determined by MC-ICPMS are consistent with those measured by negative thermal ionization mass spectrometry (N-TIMS).
187Re/
185Re ratios of the Re natural standard is 1.674 3±0.000 1(2
σ,
n=25). The value is indistinguishable within analytical uncertainty from the value adopted by IUPAC (1.674 0±0.001 1), and is also in agreement with those measured by N-TIMS (1 675 5±0.001 4) . In addition, the precise and accurate are improved by using this empirical correction technique. The Re concentration of the natural rock samples are reasonable agree with those measured by N-TIMS.