氧气动态反应-电感耦合等离子体串联质谱法测定土壤和沉积物中汞及其他6种元素的含量  

Determination of Mercury and Other 6 Elements in Soil and Sediment by Inductively Coupled Plasma Tandem Mass Spectrometry with Oxygen Dynamic Reaction

作　　者：刘跃 王记鲁 李静 王璐 王鑫 LIU Yue;WANG Jilu;LI Jing;WANG Lu;WANG Xin(TianjinEco-Environmental Monitoring Center,Tianjin30019l,China;Tianjin Hedong District Eco-Environmental Monitoring Center,Tianjin 300171,China)

机构地区：[1]天津市生态环境监测中心,天津300191 [2]天津市河东区生态环境监测中心,天津300171

出　　处：《理化检验（化学分册）》2022年第11期1241-1248,共8页Physical Testing and Chemical Analysis(Part B:Chemical Analysis)

摘　　要：采用电感耦合等离子体质谱法(ICP-MS)测定土壤和沉积物中汞含量时,由于汞元素电离能高、电离效率低,且存在钨的氧化物或氢氧化物(WO^(+)、WOH^(+))等多原子离子干扰,很难准确定量。采用电感耦合等离子体串联质谱法(ICP-MS/MS),选用202Hg作为测量同位素,在MS/MS反应模式下向动态反应池中通入氧气,使得WO^(+)、WOH^(+)等发生电子转移、去氢加氧反应,可以降低这些多原子离子对汞质量重叠的干扰。当氧气流量为2.8 mL·min^(-1),质量切割参数为0.55时,1.00 mg·L^(-1)的钨标准溶液在质荷比(m/z)202处产生的背景等效浓度(BEC)为0.003μg·L^(-1),干扰较标准模式(MS/MS)下的降低了99.9%。在优化的试验条件下,汞的检出限(3s)为0.001 mg·kg^(-1),测定有证标准物质的相对误差为-12%~17%,测定值的相对标准偏差(n=6)为2.2%~4.8%。方法满足土壤和沉积物中汞含量的测定需要,并同时应用于砷、硒、银、镉、锑、铋等多种元素的测定。The determination of mercury in soil and sediment held a low accuracy by inductively coupled plasma mass spectrometry(ICP-MS) due to high ionization energy and low ionization efficiency of mercury element, and polyatomic ion interference of tungsten oxides or hydroxides(WO^(+)and WOH^(+)). Herein, inductively coupled plasma tandem mass spectrometry(ICP-MS/MS) was applied to the analysis withHg selected as the test isotope. Under MS/MS reaction mode, the introduction of oxygen in dynamic reaction cell could reduce interference of mass overlap for mercury owing to the reactions of electron transfer, dehydrogenation and oxygenation of WO^(+)and WOH^(+). When the oxygen flow rate was 2.8 mL·min^(-1)and the mass cutting parameter was 0.55, the BEC of the 1.00 mg·L^(-1)tungsten standard solution at m/z 202 was 0.003 μg·L, which was 99.9% lower than that produced by the standard mode(MS/MS). Under optimized test conditions, the detection limit(3s) of mercury was 0.001 mg·kg. The relative errors of the certified reference materials were in the range of-12%-17%, and RSDs(n=6) of the determined values were 2.2%-4.8%. This method could meet the requirement for the determination of mercury in soil and sediment, and was applied to the determination of other elements including arsenic, selenium, silver, cadmium, antimony, and bismuth.

关 键 词：氧气动态反应 汞 电感耦合等离子体串联质谱法 土壤 沉积物 

分 类 号：O657.7[理学—分析化学]