Capillary electrophoresis on-line coupled with hydride generation-atomic fluorescence spectrometry for speciation analysis of selenium
Capillary electrophoresis on-line coupled with hydride generation-atomic fluorescence spectrometry for speciation analysis of selenium
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DOI：
10.1002/elps.200406102
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发表时间：
2005-01-01
期刊：
影响因子：
2.9
通讯作者：
Yan, XP
中科院分区：
文献类型：
--
作者：
Lu, CY;Yan, XP
采用毛细管电泳（CE）-氢化物发生-原子荧光光谱（HG-AFS）在线联用技术，将Se（VI）在线转化为Se（IV），建立了两种无机硒形态分析的新方法。在50 cm × 75 μ m内径（ID）的熔融石英毛细管中，在-20 kV下，使用15 mmol.L-1 NaH 2 PO 4和0.5 mmol.L-1十六烷基三甲基溴化铵（pH 7.5）的混合物作为电解质缓冲液，通过CE实现Se（VI）和Se（IV）的基线分离。通过将CE流出物与浓HCl混合，将Se（VI）在线还原为Se（IV）。在500 μ g.L-1（Se）水平下，两种硒的迁移时间、峰高响应和峰面积的精密度（相对标准偏差，RSD，n=7）范围为0.7 - 1.3%、6.4 - 3.7%和5.9 - 6.1%。Se（VI）和Se（IV）的检出限分别为33和25 μ g·L ~（-1）（以Se计）。在5个当地采集的水样中，两种硒的回收率为88%至114%。将该方法应用于天然水样中无机硒的形态分析。
A new method for speciation analysis of two inorganic selenium species was developed by on-line coupling of capillary electrophoresis (CE) with hydride generation-atomic fluorescence spectrometry (HG-AFS) and on-line conversion of Se(VI) to Se(IV). Baseline separation of Se(VI) and Se(IV) was achieved by CE in a 50 cm x 75 Pm inside diameter (ID) fused-silica capillary at -20 kV using a mixture of 15 mmol.L-1 NaH2PO4 and 0.5 mmol.L-1 cetyltrimethylammonium bromide (pH 7.5) as electrolyte buffer. Se(VI) was on-line reduced to Se(IV) by mixing the CE effluent with concentrated HCl. The precision (relative standard deviation, RSD, n=7) ranged from 0.7 to 1.3% for migration time, 6.4 to 3.7% for peak height response, and 5.9 to 6.1% for peak area for the two selenium species at the 500 mug.L-1 (as Se) level. The detection limits were 33 and 25mug.L-1 (as Se) for Se(VI) and Se(IV), respectively. The recoveries of the two selenium species in five locally collected water samples ranged from 88 to 114%. The developed method was applied to speciation analysis of inorganic selenium species in spiked natural water samples.