| A pretreatment method to enrich trace element Pb in corals was established with AG1-X8 anion exchange resin and self made PTFE micro column,then Pb isotopic ratios in Hainan corals（porites lutea） in China was measured by high-resolution inductively coupled plasma mass spectrometry（HR-ICP-MS）.Several parameters including procedural blank,elution curve,Pb recovery and matrix separation were compared among four different eluents,and the results showed 0.50 mol/L HNO3 was the best eluent,of which the procedural blank was 18 pg,and recovery of Pb was 99.6%,besides,there was no tailing observed and more than 99.8% of the matrix elements in corals such as Ca,Sr,Mg,Fe,Mn,U,Ba as well as Zn could be well separated from Pb during the eluting process.After eluted with 0.50 mol/L HNO3,207Pb/206Pb and 208Pb/206Pb in Hainan corals was determined to be 0.850 5 and 2.087 0,with RSDs（n=21） of 0.12% and 0.11%,respectively.All the values were located between two warning lines,which indicated the quality control was acceptable and the pretreatment method was reliable.The method established could be applied in the determination of Pb isotopic ratios in corals and other similar samples. |