Measurement of Pb isotopes for geological samples by MC-ICP-MS coupled with an extraction resin column preconcentration method

N235 extraction resin enables efficient Pb separation from geological reference materials. • Matrix are removed with dilute HBr and water, followed by Pb separation using low-concentration HBr. • The purified Pb is ready for MC-ICP-MS analysis without any evaporation step. • The method reliability is validated using various reference materials. • Pb isotope ratios of JA-1a are reported for the first time. Lead isotopic variations provide crucial insights into geochemical reservoirs, environmental sources, and geological ages. To obtain precise Pb isotope data by MC-ICP-MS, we develop a simple and efficient separation procedure using trialkyl amine (N235) resin. Batch experiments show that N235 strongly adsorbs Pb in 0.4 mol L −1 HBr, weakly in HCl, and not at all in HNO 3 media. Specifically, the optimized column procedure achieved high Pb recovery (94.5%) and eluted Pb in 0.5 mol L −1 HNO 3 , allowing direct measurement without evaporation, thereby reducing procedural blanks. The method was validated with ten reference materials (GSR-1, GSR-2, GSR-3, GSR-7, GSP-2, BHVO-2, JA-2, JG-2, JB-2, and JA-1a). Measured 206 Pb/ 204 Pb, 207 Pb/ 204 Pb and 208 Pb/ 204 Pb ratios agreed with published values within uncertainty, with external reproducibility better than 0.05% (RSD). Owing to its simplicity, high recovery, low blank, and low cost, this method offers a practical pretreatment strategy for high-precision Pb isotope analysis in diverse geological samples. A very simple, low-blank, and effective Pb purification method with a self-made trialkyl amine extraction resin is developed to separate Pb from geological reference materials for high precision determination of Pb isotopic compositions by MC-ICP-MS. Download: Download high-res image (254KB) Download: Download full-size image