微波消解-混合模式电感耦合等离子体质谱法测定土壤或沉积物中银、锡、硼

本研究使用硝酸-盐酸-氢氟酸混合消解液和高通量微波密闭消解试样，通过优化质谱进样系统，调节质谱分析模式，建立了微波消解-混合模式电感耦合等离子体质谱法同时测定土壤或沉积物中银、锡、硼。结果表明：使用混合酸消解液有利于试样中难消解的硼硅酸盐和硅锡化合物消解彻底；使用微波密闭消解方式可以提高样品消解效率，避免易挥发元素硼的损失；使用聚四氟乙烯（PTFE）雾化器和雾化室、蓝宝石中心管可有效降低由氢氟酸溶液介质腐蚀石英进样系统引入的仪器本底值；选择氦气（He）作为碰撞气，采用动能歧视模式（KED）分析银和锡，可有效降低多原子离子的干扰，特别是地球化学丰度更高的锆、铌、锌和氧、氮、氩形成的多原子离子对107Ag的干扰；选择标准模式（STD）分析硼，可有效提高对硼的方法灵敏度。在此基础上，银、锡、硼的检出限分别为0.007、0.12、0.43 mg/kg，方法精密度（RSD，n=12）和误差（RE，n=12）分别在2.29%~9.53%和-9.95%~6.10%之间。相比传统的原子发射光谱法，本方法具有分析流程简单、工作效率高、检出限低等优势，更适合大批量样品的多元素同时分析。

Determination of Sliver,Tin and Boron in Soil or Sediment Samples with Microwave Digestion by Mixed Mode Inductively Coupled Plasma-Mass Spectrometry

The analytical method of sliver, tin and boron in soil or sediment samples was developed by mixed mode inductively coupled plasma-mass spectrometry. A mixture of nitric acid, hydrochloric acid and hydrofluoric acid was utilized to digest the sample in a high-throughput closed microwave, and then the mass spectrometry sampling system was optimized and the mass spectrometry analysis mode for determination was adjusted. The mixed acid digestion solution could facilitate thorough digestion of refractory borosilicates and silicon-tin compounds in samples. Microwave sealed digestion method could improve the sample digestion efficiency and effectively avoid the loss of volatile element boron. Polytetrafluoroethylene (PTFE) atomizer, atomizer chamber and sapphire central tube could effectively reduce the background value of the instrument introduced by hydrofluoric acid solution medium corrosion quartz injection system. Using helium (He) as collision gas and the kinetic energy discrimination (KED) analysis of silver and tin could effectively reduce the interference of polyatomic ions, especially the interference of polyatomic ions formed by zirconium, niobium, zinc and oxygen, nitrogen and argon with higher geochemical abundance on 107Ag. The boron is basically free of polyatomic ion interference, so it could effectively improve the sensitivity of the method for boron by standard mode (STD). Subsequently, the detection limits of silver, tin and boron were 0.007, 0.12, 0.43 mg/kg, and the precision (RSD, n=12) and error (RE, n=12) of the method were 2.29%-9.53% and -9.95%-6.10%, respectively. Compared with the traditional atomic emission spectrometry method, this method has the advantages of simple process, high efficiency and low detection limit, which is suitable for the simultaneous analysis of multiple elements in large quantities of sample.