基于电感耦合等离子体质谱在线分析系统测定海水中9种痕量污染元素

Determination of 9 trace pollution elements in seawater by on-line analytical system of inductively coupled plasma mass spectrometer

建立了基于电感耦合等离子体质谱(ICP-MS)在线分析系统直接、在线、快速、准确、稳定测定海水中9种痕量污染元素(Cr、Ni、Cu、Zn、Se、Cd、Pb、As和Hg)的方法。优化的在线氢化物发生条件为盐酸体积分数5%、硼氢化钠质量浓度25 g/L、冲洗时间100 s,优化的在线氩气稀释条件为稀释气流量0.70 L/min,优化的ICP-MS氦气流量为1.85 mL/min。结果表明:各元素的标准曲线相关系数均大于0.999,方法检出限为0.003~0.294μg/L,定量限为0.01~0.98μg/L,加标回收率为88.7%~114.2%,精密度低于5.6%,并通过标准海水样品验证。将该方法用于厦门海沧附近某海域海水样品中9种痕量污染元素测定,除了Cu和Pb外,其他7种元素均符合《海水水质标准》(GB 3097—1997)第一类标准限值。

A direct,on-line,rapid,accurate and stable method for determination of 9 trace pollution elements(Cr,Ni,Cu,Zn,Se,Cd,Pb,As and Hg)in seawater based on on-line analytical system of inductively coupled plasma mass spectrometer was established.The optimized on-line hydride generation conditions were hydrochloric acid volume percentage of 5%,sodium borohydride mass concentration of 25 g/L and rinsing time of 100 s.The optimized on-line argon dilution condition was dilution gas flow rate of 0.70 L/min.The optimized ICP-MS helium flow rate was 1.85 mL/min.Results showed that:the standard curve coefficient of each element was above 0.999,the method detection limit was 0.003-0.294μg/L,the quantification limit was 0.01-0.98μg/L,the recovery rate was 88.7%-114.2%,and the precision was lower than 5.6%.The accuracy of the method was verified by the standard seawater samples.The method was applied to determination of the 9 trace pollution elements in seawater samples from a sea area near Haicang,Xiamen.7 elements met the first requirements of“Seawater quality standard”(GB 3097-1997)except Cu and Pb.