固相萃取-电感耦合等离子体原子发射光谱(ICP-AES)法测定地下水中三种重金属

Determination of Three Heavy Metals in Groundwater by Inductively Coupled Plasma Atomic Emission Spectrometry(ICP-AES)with Solid Phase Extraction

为拓宽固相萃取技术在生态环境监测领域应用范围,建立了树脂固相萃取前处理-ICP-AES法测定地下水中铅、铬、镉含量的方法。经前处理条件优化,硝酸洗脱液浓度5%、缓冲溶液pH=7、洗脱速率10 mL/min及进样体积为500 mL条件下,铅、铬、镉等三种重金属回收率均可以达到95%以上。各目标元素在0.02~20μg/L范围内线性关系良好,相关系数均大于0.999;铅、铬、镉的方法测定下限分别为0.56、0.04、0.24μg/L,满足评价要求;方法精密度RSD值在0.44%~5.5%;加标回收率分别在98.6%~102%、98.5%~104%、95.5%~105%。经监测井实样测试,铅、铬、镉结果处于《地下水质量标准》(GB/T 14848—2017)Ⅰ类限值范围内。方法干扰小,易操作,为相关国家标准修订提供参考。

In order to broaden the application scope of solid phase extraction technology in the field of ecological environment monitoring,a method for the determination of lead,chromium and cadmium in groundwater by ICP-AES with resin solid phase extraction pretreatment was established.A method for pretreatment of lead,chromium and cadmium in groundwater by ICP-AES with resin solid phase extraction was established.After optimizing the pretreatment conditions,the recoveries of Pb,Cr and Cd can reach more than 95%under the conditions of nitric acid eluent concentration of 5%,buffer solution pH 7,elution rate of 10 mL/min and injection volume of 500 mL.In this method,each target element is in the range of 0.02—20μg/L.The linear relationship is good in such range,and the correlation coefficients are greater than 0.999;The lower limits of Pb,Cr and Cd were 0.56,0.04 and 0.24μg/L,respectively,which meets the evaluation requirements.The relative standard deviation(RSD)of the method was 0.44%—5.5%;the recoveries were 98.6%—102%,98.5%—104%and 95.5%—105%,respectively.Through the monitoring logging sample test,the results of lead,chromium and cadmium are within the class I limit in the quality standard for groundwater(GB/T 14848—2017).This method has little interference and is easy to operate.It provides a reference for the revision of relevant national standards.