Oxidation state specific generation of arsines from methylated arsenicals based on L-cysteine treatment in buffered media for speciation analysis by hydride generation-automated cryotrapping-gas chromatography-atomic absorption spectrometry with the multiatomizer
Oxidation state specific generation of arsines from methylated arsenicals based on L-cysteine treatment in buffered media for speciation analysis by hydride generation-automated cryotrapping-gas chromatography-atomic absorption spectrometry with the multiatomizer
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DOI：
10.1016/j.sab.2007.11.037
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发表时间：
2008-03-01
影响因子：
3.3
通讯作者：
Dedina, Jiri
中科院分区：
文献类型：
--
作者：
Matousek, Tomas;Hernandez-Zavala, Araceli;Dedina, Jiri
本文介绍了一种多原子化器氢化物发生-冷捕集-气相色谱-原子吸收光谱自动分析系统。砷化氢在装有Chromosorb的U形管中进行预浓缩和分离。已经开发了一种自动低温捕获装置，其采用在检测阶段加热时形成的氮气来置换冷却的液氮。优化了填充Chromosorb的U型管分离砷化氢的条件。在60 s的阅读窗口内实现了砷化氢、甲砷化氢、二甲砷化氢和三甲砷化氢信号的完全分离。甲基化砷的检测限为4 ng 1（1）。选择性氢化物发生用于无机砷和甲基化砷的氧化态特定形态分析。砷化氢可以完全由三价或三价和五价无机砷和甲基化砷生成，这取决于L-半胱氨酸作为预还原剂和/或反应改性剂的存在。提出了TRIS缓冲反应介质，以克服在HCl介质中观察到的L-半胱氨酸修饰反应的窄的最佳浓度范围。该系统提供了统一的峰面积灵敏度为所有的物种。因此，可以用单一形式的As进行校准。这种方法允许在相对复杂的生物基质，如细胞培养系统，无需样品预处理的无机砷的代谢产物的高通量形态分析，从而保持三价和五价物种的分布。(c)2007 Elsevier B. V.保留所有权利。
An automated system for hydride generation-cryotrapping-gas chromatography-atomic absorption spectrometry with the multiatomizer is described. Arsines are preconcentrated and separated in a Chromosorb filled U-tube. An automated cryotrapping unit, employing nitrogen gas formed upon heating in the detection phase for the displacement of the cooling liquid nitrogen, has been developed. The conditions for separation of arsines in a Chromosorb filled U-tube have been optimized. A complete separation of signals from arsine, methylarsine, dimethylarsine, and trimethylarsine has been achieved within a 60 s reading window. The limits of detection for methylated arsenicals tested were 4 ng 1 (1). Selective hydride generation is applied for the oxidation state specific speciation analysis of inorganic and methylated arsenicals. The arsines are generated either exclusively from trivalent or from both tri- and pentavalent inorganic and methylated arsenicals depending on the presence Of L-cysteine as a prereductant and/or reaction modifier. A TRIS buffer reaction medium is proposed to overcome narrow optimum concentration range observed for the L-cysteine modified reaction in HCl medium. The system provides uniform peak area sensitivity for all As species. Consequently, the calibration with a single form of As is possible. This method permits a high-throughput speciation analysis of metabolites of inorganic arsenic in relatively complex biological matrices such as cell culture systems without sample pretreatment, thus preserving the distribution of tri- and pentavalent species. (c) 2007 Elsevier B.V. All rights reserved.