안정동위원소 비 측정을 위한 MC-ICP/MS 성능 평가 연구

Abstract

This study was conducted to evaluate the performance of the MC-ICP/MS by using some standard metals to test five items such as sensitivity, mass resolving power, detector noise, mass stability and precision of iso-tope ratios. The sensitivities ranged from 148 to 578 Vppm -1in the dry plasma system. The sensitivities were improved as much as 1.2~2.5 times those of previous studies. The resolution (M/∆M) at 10% peak height was as high as 8352 for 142Nd. The mass drift was 30 ppm of the peak range during the 30-minute measurement. Such high resolution and mass stability made it possible to separate purposed analytes from polyatomic inter-ferents more effectively. The noise levels of faraday detectors (1.5~2.7×10-5V) and ion counting multipliers (0.01~0.1 cps) were well below the performance standard. Analyzing the isotope ratios of Li, Sr, Nd, Pb and U standard solutions showed that all but Li isotope ratios were in good agreement with those reported in the previous studies. In conclusion, this study may build a new foundation for environmental research by sug-gesting the use of isotope ratios to trace heavy metal sources and estimate their contributions, which will over-come limitations in the existing methods of residual investigation and modeling.