MAE-ICP-MS法同时测定朱砂中硫化汞、可溶性汞盐含量

目的: 建立微波辅助萃取-电感耦合等离子体质谱法(MAE-ICP-MS法)同时测定朱砂中硫化汞(HgS)、可溶性汞盐(以Hg计)含量. 方法: 朱砂样品采用微波辅助萃取(MAE),分别以密闭式微波消解法、密闭式微波提取法进行前处理,以²⁰⁹Bi作为Hg的内标,控制分析信号的动态漂移,用电感耦合等离子体质谱法(ICP-MS)测定总Hg、可溶性Hg含量,再折算成硫化汞、可溶性汞盐(以Hg计)含量. 结果: 线性相关系数(r)为1.000;回收率均为95%~105%;精密度RSD均≤1%;重复性RSD均≤0.4%;稳定性:硫化汞RSD≤0.1%,可溶性汞盐(以Hg计)RSD≤1%;方法检出限(LOQ):硫化汞为6 mg·g^-1,可溶性汞盐(以Hg计)为0.06 μg·g^-1.同时对国家标准物质大米 、硫化汞对照品进行分析,Hg、HgS含量均在其标准值范围内. 结论: 本法的方法检出限(LOQ)、精密度、准确度、重复性、稳定性试验结果均满足要求,可用于测定朱砂中硫化汞、可溶性汞盐(以Hg计)含量.

Objective: To establish microwave assisted extraction-inductively coupled plasma mass spectrometry (MAE-ICP-MS) for simultaneous determination of the contents of mercuric sulfide (HgS),soluble mercury salt (calculated by Hg) in cinnabar. Methods: Cinnabar samples were pretreated with closed microwave digestion and closed microwave extraction.The signal dynamic drift was analyzed with ²⁰⁹Bi as the internal standard of Hg.The inductively coupled plasma mass spectrometry (ICP-MS) method was used for the determination of the contents of total Hg and soluble Hg,and the obtained results were converted into the contents of mercuric sulfide and soluble mercury salt (calculated by Hg). Results: The linear correlation coefficient (r) was 1.000;recoveries were 95%-105%;precision RSDs were ≤1%;repeatability RSDs were ≤0.4%.For stability,mercuric sulfide RSD was ≤0.1%,soluble mercury salt (calculated by Hg) RSD was ≤1%.The method detection limit (LOQ) for mercuric sulfide was 6 mg·g^-1,for soluble mercury salt (calculated by Hg) was 0.06 μg·g^-1.Meanwhile,the national standard rice and the reference substance of mercury sulfide were also analyzed,and the results showed Hg,HgS levels were within the range of its standard value. Conclusion: The method detection limit (LOQ),precision,accuracy,repeatability,stability testing results meet the requirements for the determination of the contents of mercuric sulfide and soluble mercury salt (calculated by Hg) in cinnabar.