高效液相色谱-电感耦合等离子体质谱法同步测定海水中的无机砷与六价铬

Simultaneous analysis of inorganic arsenics and chromium(Ⅵ)in sea water by high performance liquid chromatography-inductively coupled plasma mass spectrometry

建立高效液相色谱-电感耦合等离子体质谱法同步分离和测定海水中亚砷酸盐[As(Ⅲ)]、砷酸盐[As(Ⅴ)]和六价铬[Cr(Ⅵ)]的分析方法。海水样品直接进样,以40 mmol/L pH 9的硝酸铵溶液作为流动相,使用Hamilton PRP-X100阴离子交换色谱柱对待测组分进行分离,实现了亚砷酸根、砷酸根和六价铬3种元素形态的分离与测定。3种元素形态的线性范围分别为:As(Ⅲ),As(Ⅴ)10~250μg/L;Cr(Ⅵ)20~500μg/L。检出限分别为3,3,6μg/L,加标回收率为85.1%~95.4%,相对标准偏差为1.0%~3.8%(n=6)。该方法操作简便,可同步测定海水中砷和铬的元素形态。

A method for the simultaneous separation and determination of three species of As(Ⅲ),As(Ⅴ)and Cr(Ⅵ)in sea water was established by high performance liquid chromatography-inductively coupled plasma mass spectrometry.40 mmol/L NH4NO3 solution was used as the mobile phase which was adjusted to pH 9,sea water samples were directly injected then separated by Hamilton PRP-X100 anion exchange chromatography.The three element species including As(Ⅲ),As(Ⅴ),Cr(Ⅵ)were successfully separated by the developed method.The three analytes showed good linearity in certain concentration range[As(Ⅲ)/As(Ⅴ):10-250μg/L;Cr(Ⅵ):20-500μg/L].The detection limits(LODs)of the three analytes were 3,3,6μg/L,respectively.The recoveries for the analytes were between 85.1%and 95.4%while the relative standard deviations were 1.0%-3.8%(n=6).This method is simple,and it provide a useful tool for the speciation analysis of arsenic and chrome in sea water.