【摘要】 基于自动化树脂分离富集装置对海水中痕量金属元素(Cu、Pb、Zn和Cd)的预分离富集技术和电感耦合等离子体质谱仪,建立了一种适用于河口区及近岸海域海水中痕量金属元素的分析方法,利用该方法对长江口及其邻近海域的实际海水样品进行分析。结果表明:当海水样品pH<2时,与pH为6.0±0.1的醋酸铵缓冲溶液按一定体积比例(13∶2～13∶5)混合后加载到树脂柱,4种目标元素(Cu、Pb、Zn和Cd)可以在树脂柱上实现稳定吸附;以不低于800μL的醋酸铵缓冲溶液冲洗吸附后的柱体,可以有效去除碱金属、碱土金属和阴离子等干扰物质;以不低于600μL的洗脱液(10%的硝酸溶液)以200μL/min的速率反冲吸附后的柱体,4种目标元素可同时达到较高的回收率。在最优实验条件下,新方法对Cu、Pb、Zn和Cd的检出限分别为0.014、0.002、0.049和0.001μg/L,同时表现出了自动化程度高、消耗样品和试剂体积小的优点。新方法对长江口及其邻近海域的海水中Cu、Pb、Zn和Cd的分析结果与海洋监测规范中的标准方法分析结果之间没有显著性差异(P>0.05),表明该方法的稳定性强且不受盐度的影响,适用于河口区及其邻近海域的痕量金属元素的分析工作。更多还原

【Abstract】 In this study, we present an analytical approach which uses an automated pre-concentration device(seaFAST) with accurate volume loading and in-line pH buffering of the sample prior to loading onto the chelating resin(NOBIAS chelate-PA1) and subsequent simultaneous analysis of copper(Cu), lead(Pb), zinc(Zn) and cadmium(Cd) by Inductively Coupled Plasma Mass Spectrometry(ICP-MS). The available system extracts the trace metals from the seawater onto a chelation resin column, when the seawater sample pH<2, mixed with the buffer solution of ammonium acetate with pH(6.0±0.1) in a certain volume ratio(13∶2～13∶5). And the resin can be washed with the buffer solution of ammonium acetate no less than 800μL, which can effectively remove alkali metals, alkaline-earth metals, anions, etc. The four target elements can achieve high recovery at the same time when the resin eluted by 10% nitric acid which is no less than 600 μL at the rate of 200 μL/min. The detection limits of this method were 0.014 μg/L(Cu), 0.002 μg/L(Pb), 0.049 μg/L(Zn), 0.001 μg/L(Cd).The analytical technique has advantages of high automation and small volume of reagents and samples. There is no significant difference of the analytical results, which is the trace metals in seawater of Changjiang Estuary and its adjacent areas, between this method and the one of the specification for marine monitoring. It shows that this method is stable and not affected by salinity. It is suitable for the analysis of trace metals in the estuary and its adjacent areas.更多还原