氩同位素分析样品管的改造  

Modification of Sample Tube Used for Determining Ar Isotopes

作　　者：苗国均[1] 刘玉琳[1] 马芳[1] 

机构地区：[1]北京大学造山带与地壳演化教育部重点实验室和地质学系,北京100871

出　　处：《北京大学学报（自然科学版）》2007年第4期493-495,共3页Acta Scientiarum Naturalium Universitatis Pekinensis

基　　金：国家自然科学基金(40503006)资助项目

摘　　要：随着质谱仪性能的改进,熔样系统成为影响Ar同位素分析精度的主要因素。将原来的单进样管改造成为多进样管,可以预先去气和测量热空白值,降低了非放射成因氩对测试结果的影响,这对于年轻火山岩的定年尤为重要;同时还大大节约了测试时间。长期的测试实践证明,熔样钼坩锅外面的石英管是影响热空白的主要因素。对石英管的形状进行了改造,使其与钼坩锅接触的石英材料减少到原来的大约1/5,进一步降低了热空白并减少了去气时间。通过对样品管的改造,提高了样品测试中放射成因氩的含量,标样多次测试结果具有很好的重现性和准确度。While testing capability of mass spectrometer has been improved, sample fusion system becomes the main factor to effect Ar isotopes determination. Sample tube has been reconstructed from mono-tube to multiple-tube. After reconstruction, it allowes us to remove atmosphere Ar and measure hot blank beforehand. This reduces the influence of non-radiogenic Ar to measuring results,which plays an important role especially to young volcanic rocks. Moreover, measuring time is saving. The second change that has made is quartz tube from cylinder-shape to three-pinstripe. Quartz material contacted to the molybdenum crucible reduces to one fifth. This makes hot blank even lower and the removal time is shorter. After modification of sample tube, the content of radiogenic Ar increases and reproducibility and accuracy of standards is better.

关 键 词：氩同位素 样品管 改造 

分 类 号：P597[天文地球—地球化学]