建立了飞秒激光剥蚀-多接收电感耦合等离子质谱(fLA-MC-ICPMS)铅同位素原位微区分析方法, 分别利用溶液法(SN-MC-ICPMS)和激光剥蚀法(fLA-MC-ICPMS)对15个铜(黄铜, 青铜)国家标准物质进行了实验分析, 测试的结果表明CuPb12(GBW02137)中Pb同位素组成非常均一, 可作为以铜为基体的青铜、 黄铜及铜矿中Pb同位素原位微区分析的外部参考物质。 对CuPb12 进行了112次fLA-MC-ICPMS Pb同位素分析测试, 其加权平均值与溶液法测定的Pb同位素比值在2σ误差范围内完全一致, 208Pb/204Pb和207Pb/206Pb比值的内部精度RSE分别小于90和40 ppm, 外部精度RSD分别小于60和30 ppm。 利用本实验室建立的fLA-MC-ICPMS分析方法对13个古铜钱币中Pb同位素进行了原位微区无损伤分析, 测试结果表明, 不同朝代古钱币中Pb同位素组成差异较大, 即使同一朝代的古钱币其Pb同位素组成也不尽相同。

In the present study we set up a femtosecond laser ablation MC-ICP-MS method for lead isotopic analysis. Pb isotopic composition of fifteen copper (brass, bronze) standard samples from the National Institute of Standards Material were analyzed using the solution method (MC-ICP-MS) and laser method (fLA-MC-ICPMS) respectively, the results showed that the Pb isotopic composition in CuPb12 (GBW02137) is very homogeneous, and can be used as external reference material for Pb isotopic in situ analysis. On CuPb12 112 fLA-MC-ICPMS Pb isotope analysis, the weighted average values of the Pb isotopic ratio are in good agreement with the results analyzed by bulk solution method within 2σ error, the internal precision RSEs of the 208Pb/204Pb ratio and 207Pb/206Pb ratio are less than 90 and 40 ppm respectively, and the external precision RSDs of them are less than 60 and 30 ppm respectively. Pb isotope of thirteen ancient bronze coins was analyzed via fLA-MC-ICPMS, the results showed that the Pb isotopic composition of ancient coins of different dynasties is significantly different, and not all the Pb isotopic compositions in the coins even from the same dynasty are in agreement with each other.