用于MC-ICP-MS测定环境样品中铜、锌同位素的化学分离方法

Chromatographic separation of Cu and Zn from environmental samples for determination of isotopic composition by MC-ICP-MS

对不同离子交换柱、淋洗体积、盐度、分离次数等一系列影响铜、锌纯化分离效果的条件进行了探讨,确定了环境样品(湖泊沉积物、植物和颗粒物)中铜、锌同位素测定时化学分离的最佳条件。采用AGMP-1(100～200目)阴离子交换树脂,以7mol/LHCl+0.001%H2O2、2mol/LHCl+0.001%H2O2、0.5mol/LHNO3作为淋洗液,分别在适当的体积接收淋洗液,可以有效地分离沉积物、植物和悬浮物等样品中的铜和锌。化学分离过程中Cu和Zn的回收率接近100%,同位素分馏在测试误差范围以内。将此方法应用于对红枫湖和阿哈湖水体悬浮物、植物和鱼类等样品中Cu、Zn的分离,经MC-ICP-MS测试后,准确获得了这些样品的Cu、Zn同位素组成。

The factors influencing chromatographic separation of Cu and Zn from environmental samples （sediment,plant and suspended particulate material）,such as resin column,elution volume,salinity and separation times were experimentally studied,and the optimal conditions of separating Cu and Zn from environmental samples were decided. AG MP-1 resin （100-200 mesh） was used as anion exchange resin and 7 mol/L HCl ＋ 0.001% H2O2,2 mol/L HCl＋ 0.001% H2O2,0.5 mol/L HNO3 were used as eluants,and then the eluants were collected at fitting volume respectively. This procedure can separate Cu and Zn effectively from sediment,plant,and suspended particulate matter （SPM） samples,the yield of which is close to 100%,and the isotope fractionation during which is small enough to be neglected. This method was successfully applied to the separation of Cu and Zn from the sediment,plant and suspended particulate materials in Hongfeng and Aha Lakes,and the δ65Cu and δ66Zn values of those samples were measured exactly by MC-ICP-MS.