Simultaneous Determination of U-Pb Age and Trace Elements of Zircon by Laser Ablation Sector Field Inductively Coupled Plasma-Mass Spectrometry

Laser ablation sector field inductively coupled plasma-mass spectrometry (LA-SF-ICP-MS) is widely applied in U-Pb dating of zircon due to its remarkable sensitivity. However, the utilization of a magnetic sector mass analyzer imposes constraints on its scanning speeds, potentially affecting the concurrent acquisition of U-Pb isotopes and other trace elements. Here a method for simultaneous zircon U-Pb dating and key trace elements quantifying by LA-SF-ICP-MS were developed. Seven zircon U-Pb standard samples were measured to assess the method's feasibility. Experimental data indicate that simultaneous collection of U-Pb isotopes and other trace elements may decrease signal stability, particularly for low-content isotopes like ²⁰⁷Pb, which in turn leads to an increased age uncertainty and dispersion for single analyses. However, the accuracy of the concordance age and weighted mean ²⁰⁶Pb/²³⁸U age of each sample, and the statistical results of all data points, are not affected significantly. Compared to TIMS ages, the discordance in these ages across all samples remains below 1.0% and 0.7%, respectively, meeting the requirements of U-Pb geological dating. Furthermore, the determination of key trace elements in zircon samples shows relative errors to recommended values of less than 10%. LA-SF-ICP-MS can accurately determine both zircon U-Pb ages and trace element contents simultaneously. The BRIEF REPORT is available for this paper at http://www.ykcs.ac.cn/en/article/doi/10.15898/j.ykcs.202309110151.