硅胶负载碳纳米管分离富集水中痕量银  

Carbon Nanotubes Loaded Silica Gel for Preconcentration of Trace Silver with Detection by Flame Atomic Absorption Spectrometry

作　　者：于洪梅[1,2] 孙巍[2] 陈明丽[1] 田永[1] 王建华[1] 

机构地区：[1]东北大学分析科学研究中心,沈阳110819 [2]辽宁科技大学化工学院,鞍山114051

出　　处：《分析化学》2010年第12期1721-1726,共6页Chinese Journal of Analytical Chemistry

基　　金：国家自然科学基金(国家杰出青年科学基金(No.20725517);重大国际合作项目(No.20821120292);面上项目(No.20805004);中央高校基本科研业务费(Nos.90105001;90405004;90405004)资助项目

摘　　要：以NaOH为沉淀试剂,将水样中的Ag+在线生成Ag2O沉淀,并即时被滞留在硅胶负载的碳纳米管表面。被吸附的Ag2O沉淀用HNO3(10%,V/V)洗脱,并用火焰原子吸收法检测。当进样体积为5.4mL时,线性范围为1～120μg/L,富集系数为34.5;检出限为0.35μg/L;相对标准偏差为0.5%(40μg/L,n=7),采样频率为47次/h。结果表明:本方法的富集系数、检出限及精密度均明显优于以纯碳纳米管和纯硅胶微珠为吸附剂收集Ag2O的体系。将此系统应用于实际水样中银的测定,加标回收率在96%～108%之间。Carbon nanotubes(CNTs) were loaded onto the surface of silica gel(SG) beads,and the CNTs/SG composite was used as a novel adsorbent for the preconcentration of trace silver in a flow system by adsorbing nascent Ag2O in the solution.This treatment of the material significantly improved the mechanical strength and capability of preconcentration of carbon nanotubes.With NaOH as precipitating reagent,the nascent Ag2O in the solution was readily retained on the surface of the CNTs/SG composite,and afterwards,it was recovered by elution with nitric acid(10%,V/V).The eluate was finally introduced into the flame atomic absorption spectrometer for quantification.By loading 5.4 mL of sample solution,in the liner range of 1-120 μg/L,an enrichment factor of 34.5,a detection limit of 0.35 μg/L and a precision of 0.5% RSD at the level of 40 μg/L(n = 7) were obtained,along with a sampling frequency of 47 h-1.The enrichment factor,the detection limit as well as the precision of this procedure are obviously superior to that achieved by using either pure carbon nanotubes or pure silica gel as adsorbents.The procedure was applied for the determination of silver in water samples,and satisfactory spiking recoveries were obtained in the range of 96%-108%.

关 键 词：硅胶负载碳纳米管 流动注射 分离富集 氧化银 火焰原子吸收法 

分 类 号：X832[环境科学与工程—环境工程]