磁性纳米材料固相萃取/火焰原子吸收光谱法测定环境水样中的痕量银离子  

Determination of Trace Silver Ion in Environmental Water Samples by Solid Phase Extraction Using Magnetic Nanomaterial and Flame Atomic Absorption Spectrometry

作　　者：邹建平[1] 马晓国[1] 党永锋[1] 李萍[1] 

机构地区：[1]广东工业大学环境科学与工程学院,广东广州510006

出　　处：《分析测试学报》2013年第9期1139-1142,共4页Journal of Instrumental Analysis

基　　金：国家自然科学基金资助项目(20875018)

摘　　要：在纳米四氧化三铁表面包覆二氧化硅，并以十八烷基三甲氧基硅烷进行化学修饰，用作固相萃取吸附剂富集环境水样中的痕量银离子，用火焰原子吸收光谱法测定，建立了一种灵敏、快速、简便分析银离子的新方法。考察了水样pH值、吸附剂用量、螯合剂用量、振荡时间、洗脱剂、共存离子等对银离子回收率的影响。实验结果表明，对于200 mL水样，在pH 7.0、吸附剂用量为0.1 g、螯合剂5-Br-PADAP（0.5 g/L）用量为0.6 mL、吸附时间为10 min的条件下，材料对Ag＋具有较好的吸附性，且用6 mL 1.0 mol/L的硝酸可完全洗脱所吸附的Ag＋。在优化实验条件下，检出限（3σ）为0.15 μg/L，相对标准偏差（10 μg/L，n=6）为1.4%，富集因子达31。分别对河水、湖水样品中Ag＋进行检测，加标回收率为85.0%-94.8%。Fe3O4 nano-particles coated with silica were chemically modified with trimethoxyoctadecylsilane,and then used as the adsorbent for solid phase extraction of silver ion chelated with 5-Br-PADAP in environmental water samples.Coupled with flame atomic absorption spectrometry,a new analytical method for sensitive,rapid and simple determination of trace amount of silver ion in aqueous samples was developed.Effects of some experimental factors such as water sample pH,amount of adsorbent and chelating agent,oscillating time,eluent type and volume,coexisting ions,on the recovery of silver ion were investigated and optimized.The results showed that for 200 mL water sample,the optimal conditions were as follows：sample pH：7.0,adsorbent amount：0.1 g,volume of 5-Br-PADAP solution（0.5 mg/L）：0.6 mL,oscillating time：10 min.The adsorbed silver ion could be completely eluted off by using 6 mL 1.0 mol/L nitric acid.Under the optimized conditions,the detection limit for Ag＋ was 0.15 μg/L with an enrichment factor of 31,and the relative standard deviation was 1.4%（10 μg/L,n=6）.The proposed method was applied in the analysis of Ag＋ in river water,lake water samples with spiked recoveries of 85.0%-94.8%.

关 键 词：磁性纳米材料 固相萃取 火焰原子吸收光谱法 银离子 水样 

分 类 号：O657.3[理学—分析化学] O614.122[理学—化学]