论文部分内容阅读
岩石中低含量碘的测定是分析化学的一大难题。过去由于使用的分析方法灵敏度不够，岩浆岩碘含量的测定结果偏高，以此为基础计算出来的克拉克值也偏高。放射化学中子活化（RNAA）和同位素稀释质谱（IDMS）分析法可以对岩石中ng／g级碘进行精确测定，在80年代后期克服了一些技术上的难题后，得到了一批可靠的岩石碘含量分析结果。根据最新分析结果计算出岩浆岩、沉积岩和变质岩碘的平均含量分别为18．8、724、166.9（ng／s）。以此为基础计算碘的克拉克值为115ng／g。这一结果只相当于文献值的1／3－1／10。
The determination of low levels of iodine in rock is a major challenge in analytical chemistry. In the past, due to the lack of sensitivity of the analytical methods used, the determination of iodine in the magmatic rock was high, and the Clarke value calculated on the basis of this was also high. Radiochemical neutron activation (RNAA) and isotope dilution mass spectrometry (IDMS) can accurately determine ng / g grade iodine in rocks and overcome some technical difficulties in the late 1980s, resulting in a number of reliable rocks Iodine content analysis results. According to the latest analysis results, the average contents of iodine in magmatic rock, sedimentary rock and metamorphic rock are calculated as 18.8,724,166.9 (ng / s) respectively. Based on this calculation, the Clarke value of iodine was 115 ng / g. This result is only 1 / 3-1 / 10 of the literature value.