Thermal ionization mass spectrometry of stable chlorine isotopes for planetary materials: Current status and a new development

Abstract

IRMS and TIMS have been applied to stable chlorine isotope analyses for planetary materials. Because of high sensitivity and good precision, TIMS technique should has an important role. The d37Cl(SMOC) by TIMS are systematically higher than those of IRMS, which has not been well explained. After repeated long runs for seawater, laboratory std and silicate rocks, it was found that 37Cl/35Cl correlates positively with Cs/Cs2Cl for seawater, and that silicate samples indicate occasionally higher d37Cl due to higher Cs/Cs2Cl, which causes serious data reduction errors. Our results suggest re-evaluation of TIMS data so-far reported urgently required.