Determination of Lead Isotope by Dual Gas Flow Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry

A method to determine lead isotope ratio in the geological sample with dual gas flow calibration-laser ablation inductively coupled with plasma-mass spectrometry (LA-ICP-MS) was described. 201Hg and the exponent principle were used to calibrate the isobaric interference and mass discrimination in LA-ICP-MS analysis, respectively. The results showed that the intensities of analytical signal for Pb were extremely improved with dual gas flow system. The optimum signal intensities and the precision of isotope ratio were obtained when the ratio of the flows between dry aerosols and wet aerosols was about 1. The proposed method was applied to analyze geological standard reference materials such as NIST610 and BCR-2G, and the analytical results were in good agreement with the reference values with RSD ≤ 1% (n = 8).