| 微量硫化物、硫酸盐硫同位素EA-IRMS在线测试分析 |
| |
| 关键词:micro-sample sulfur isotope EA-IRMS online analysis |
| 基金项目:国家自然科学基金项目(编号: 41627802; 41973022);基本科研业务费项目(编号: YYWF201710) |
| 作者 | 单位 | E-mail | | 武晓珮 | 中国地质科学院矿产资源研究所, 自然资源部成矿作用与资源评价重点实验室,自然资源部同位素地质重点实验室
北京大学地球与空间科学学院 | wxp92@pku.edu.cn | | 范昌福 | 中国地质科学院矿产资源研究所, 自然资源部成矿作用与资源评价重点实验室,自然资源部同位素地质重点实验室 | tjfchangfu@163.com | | 胡斌 | 中国地质科学院矿产资源研究所, 自然资源部成矿作用与资源评价重点实验室,自然资源部同位素地质重点实验室 | | | 高建飞 | 中国地质科学院矿产资源研究所, 自然资源部成矿作用与资源评价重点实验室,自然资源部同位素地质重点实验室 | | | 李延河 | 中国地质科学院矿产资源研究所, 自然资源部成矿作用与资源评价重点实验室,自然资源部同位素地质重点实验室 | |
|
| 摘要点击次数: 2842 |
| 全文下载次数: 1702 |
| 摘要: |
| Micro-sulfur Isotopic Measurement in Sulfide and Sulfate by Online EA-IRMS Analysis |
| During the conventional sulfur isotopic measurement by EA-IRMS, Ag2S and BaSO4 sample weight required for the precise analysis is 0.2~1.0 mg and 0.35~1.5 mg respectively. The sample sizes mentioned above can hardly satisfy the requirements for micro-analysis and precious samples. Moreover, it is easy to cause the sample residue in the testing system with such big sample weight, and the data cannot reflect the real result. Therefore, how to reduce the sample sizes needed for the measurement has become the major problem to be solved in the EA-IRMS testing. Through the research on the EA-IRMS system, it has been found that the sample utilization rate by conventional method is only 0.3%, and 99.7% target gas will be wasted on account of the difference between the initial He carrier gas flow rates (100 mL/min), the flow rate entering the open split (10 mL/min) and the required flow rate entering the ion source (0.3 mL/min). As a result, the key to decreasing the loss of sample and to improving the utilization rate of the sample during the testing so as to reduce the sample weight for testing is to narrow the disparity of carrier gas flow rates. In this study, the authors made a key improvement compared with the traditional EA-IRMS technology that a device is designed between the Elemental Analysis (EA) and the open split composed of a six-port valve switching the He carrier gas flow rate (10 mL/min), and the Load-Inject mode converting and a self-heated cold trap gathering the SO2 in the Load mode. After the switch of the Load-Inject mode in the system, the cryogenic SO2 gathered in the cold trap will enter into the open split through the purge of the matched back-flushing He carrier gas in order to ensure the SO2 produced by sample combustion to be collected completely. This improvement can increase the sample utilization rate by 10 times, and the sulfur amount needed for the system can be reduced to 3~13 μg theoretically. Furthermore, this improvement can also increase the testing efficiency for its extended reaction tube service life and the reduced ash cleaning frequency. At the same time, the peak-tailing can be avoided during the testing so as to improve the measurement precision. The data of sulfide (Ag2S) and sulfate (BaSO4) samples obtained by this micro-sulfur isotopic measurement are consistent with the results of the traditional method. In addition, the data analysis precision better than 0.15‰ (1SD) and the difference value between the true and the measured value within 0.4‰ have reached the advanced level of the similar international laboratories. Furthermore, such a method can provide relevant experience for micro-organic carbon and nitrogen isotopic measurements by EA-IRMS analysis. |
| WU Xiao-pei,FAN Chang-fu,HU Bin,GAO Jian-fei,LI Yan-he.2020.Micro-sulfur Isotopic Measurement in Sulfide and Sulfate by Online EA-IRMS Analysis[J].Acta Geoscientica Sinica,41(5):605-612. |
| 查看全文 查看/发表评论 下载PDF阅读器 |
|
|
|
|
|