Zhurnal Analiticheskoi Khimii, Volume 79, Nº 9 (2024)

The trace element composition and isotope ratios of Pb/U, Pb/Th and Pb/Pb in apatite were determined by inductively coupled plasma mass spectrometry and laser ablation (LA) on a NexION 300S device with a NWR 213 laser ablation accessory, and the procedure for processing experimental data was described. The optimal performance parameters of the mass spectrometer and the laser attachment were determined, including in determining the trace element composition and U/Pb dating from a single crater with a size of 50 μm or more. Standard synthetic glasses NIST SRM-612, -610 were used to determine the trace element composition of apatite; reference samples (RS) were used to measure isotope ratios – Durango, Mun Mad and Mud Tank apatites analyzed in laboratories in different countries. According to scanning electron microscopy data, the shape of laser ablation craters in apatite RS grains was analyzed; significant grain heterogeneity in the content of matrix and impurity elements was shown. The metrological characteristics of the methods for the measurement period 2021-2023 are presented. The repeatability of measuring the isotope ratios of ²⁰⁶Pb/²³⁸U and ²⁰⁸Pb/²³²Th is 0.54 and 0.72, 7.5 and 14.3, 1.5 and 4.4% for Mun Mad, Durango, Mud Tank, respectively. The variations in REE content in the reference samples (s_r) are 11-24, 5-13, 0.3–7% for Mun Mad, Durango, Mud Tank, respectively. The dating of apatite OS within the limits of uncertainty corresponds to those obtained in world laboratories. The methods were tested in the analysis of a number of apatite samples from Ural sites.