Flow injection on-line solid phase extraction for ultra-trace lead screening with hydride generation atomic fluorescence spectrometry.
Flow injection on-line solid phase extraction for ultra-trace lead screening with hydride generation atomic fluorescence spectrometry.
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DOI：
10.1039/b511829h
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发表时间：
2006-12
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影响因子：
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通讯作者：
Zhuo Wan;Zhangrun Xu;Jianhua Wang
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文献类型：
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作者：
Zhuo Wan;Zhangrun Xu;Jianhua Wang
建立了流动注射(FI)在线固相萃取(SPE)分离和预富集超痕量铅，氢化物发生-原子荧光光谱分析(AFS)的方法。铅被保留在亚氨基二乙酸酯螯合树脂填充的微柱上，然后用2.5%(v/v)的盐酸洗脱，以1%(m/v)的铁氰化钾作为氧化(或增敏)试剂，与碱性四氢硼酸盐溶液反应促进氢化物的生成。在气液分离器中将氢化物从反应介质中分离出来，并扫入雾化器进行定量。对化学变量和FI流动参数进行了精心优化。当进样量为4.8ml时，铅的定量保留系数为11.3，采样频率为50h(-1)。检出限为4 ng L(-1)，定义为空白标准偏差(3西格玛)的3倍，在0.4微克L(-1)水平上的相对标准偏差为1.6%。通过对两个标准物质中铅含量的测定，验证了该方法的有效性，并通过对多种生物和环境样品的分析，进一步证明了该方法的实用性。
A flow injection (FI) on-line solid phase extraction (SPE) procedure for ultra-trace lead separation and preconcentration was developed, followed by hydride generation and atomic fluorescence spectrometric (AFS) detection. Lead is retained on an iminodiacetate chelating resin packed microcolumn, and is afterward eluted with 2.5% (v/v) hydrochloric acid to facilitate the hydride generation by reaction with alkaline tetrahydroborate solution with 1% (m/v) potassium ferricyanide as an oxidizing (or sensitizing) reagent. The hydride was separated from the reaction medium in the gas-liquid separator and swept into the atomizer for quantification. The chemical variables and the FI flow parameters were carefully optimized. With a sample loading volume of 4.8 ml, quantitative retention of lead was obtained, along with an enrichment factor of 11.3 and a sampling frequency of 50 h(-1). A detection limit of 4 ng l(-1), defined as 3 times the blank standard deviation (3 sigma), was achieved along with a RSD value of 1.6% at the 0.4 microg l(-1) level. The procedure was validated by determining lead contents in two certified reference materials, and its practical applicability was further demonstrated by analysing a variety of biological and environmental samples.