激光原位 LA-MC-ICP-MS 测定地质样品 Sm-Nd 同位素方法新进展

The new progresses in analytical methods of in situ Sm-Nd isotope measurement of natural geological samples by using laser ablation multi-collector ICP mass spectrometry (LA-MC-ICP-MS) since 2006 have been reviewed in this paper. The review is focused on description of analytical protocol for isobaric interference correction of in situ Sm-Nd isotopie measurement by using LA-MC-ICP-MS. As it suggested, the reliable ¹⁴⁷Sm/¹⁴⁴Nd and ¹⁴³Nd/¹⁴⁴Nd data of light REE enriched accessory minerals can be obtained by using LA-MC-ICP-MS. This is a primary technique for the in site Sm-Nd i-sotopic measurement of geological samples at present. Combining with U-Th-Pb dating and trace element analysis of accessory minerals, some important geochemical constraint parameters on the genetic evolution of those accessory minerals could be obtained. It is prospective that the combined in situ measurement technique for analyzing multiple isotopie systems (such as Sr-Nd-Hf isotopes), dating U-Th-Pb ages, analyzing trace elements of low contents geological samples (<500 ppm), and measuring precisely the Sm-Nd isotopie compositions of minerals with high Sm/Nd ratios (such as the Sm/Nd ratio of xenotime is much higher than 1, even up to 10) will be one of the major development directions for the in situ Sm-Nd isotopie measurement by using LA-MC-ICP-MS in the near future.