Speciation analysis of arsenic in biological matrices by automated hydride generation-cryotrapping-atomic absorption spectrometry with multiple microflame quartz tube atomizer (multiatomizer)
Speciation analysis of arsenic in biological matrices by automated hydride generation-cryotrapping-atomic absorption spectrometry with multiple microflame quartz tube atomizer (multiatomizer)
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DOI：
10.1039/b706144g
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发表时间：
2008-03-01
影响因子：
3.4
通讯作者：
Styblo, Miroslav
中科院分区：
文献类型：
--
作者：
Hernandez-Zavala, Araceli;Matousek, Tomas;Styblo, Miroslav
对长期接触无机砷（iAs）的个体的组织和体液中砷（As）形态的分析提供了有关iAs代谢的暴露水平和模式的重要信息。我们之前已经描述了通过氢化物发生原子吸收光谱法（HG-AAS）对生物基质中As物质进行特定氧化态分析，使用低温捕获（CT）预浓缩和分离砷化氢。为了提高该方法的性能和检测限，HG和CT步骤是自动化的，并且用最近开发的多微火焰石英管雾化器（multiatomizer）代替传统的火焰管雾化器。在此系统中，砷-III-物种的胂生成在Tris-HCl（pH 6）和硼氢化钠的混合物。为了从As-III-和As-V-物质生成砷化氢，样品用L-半胱氨酸预处理。在这些条件下，二甲基硫代胂酸，一种新描述的代谢产物的iAs，不干扰显着与甲基化三价砷的检测和定量。通过分析含有iAs单和二甲基化代谢物的培养细胞和小鼠组织，表征了自动HG-CT-AAS的分析性能。使用含有重组大鼠砷（+3氧化态）甲基转移酶和iAs处理的培养大鼠肝细胞的体外甲基化系统，验证了检测甲基化As-III-和As-V-物质的能力。与以前的HG-CT-AAS设计相比，iAs及其代谢物的检测限显着提高与当前系统，范围从8至20 pg。As的回收率在78和117%之间。该方法的精密度优于5%的所有生物基质检查。因此，自动化HG-CT-AAS系统提供了一种有效和灵敏的工具，用于分析复杂生物基质中iAs的所有主要人体代谢物。
Analyses of arsenic (As) species in tissues and body fluids of individuals chronically exposed to inorganic arsenic (iAs) provide essential information about the exposure level and pattern of iAs metabolism. We have previously described an oxidation state-specific analysis of As species in biological matrices by hydride-generation atomic absorption spectrometry (HG-AAS), using cryotrapping (CT) for preconcentration and separation of arsines. To improve performance and detection limits of the method, HG and CT steps are automated and a conventional flame-in-tube atomizer replaced with a recently developed multiple microflame quartz tube atomizer (multiatomizer). In this system, arsines from As-III-species are generated in a mixture of Tris-HCl (pH 6) and sodium borohydride. For generation of arsines from both As-III- and As-V-species, samples are pretreated with L-cysteine. Under these conditions, dimethylthioarsinic acid, a newly described metabolite of iAs, does not interfere significantly with detection and quantification of methylated trivalent arsenicals. Analytical performance of the automated HG-CT-AAS was characterized by analyses of cultured cells and mouse tissues that contained mono- and dimethylated metabolites of iAs. The capacity to detect methylated As-III- and As-V-species was verified, using an in vitro methylation system containing recombinant rat arsenic ( + 3 oxidation state) methyltransferase and cultured rat hepatocytes treated with iAs. Compared with the previous HG-CT-AAS design, detection limits for iAs and its metabolites have improved significantly with the current system, ranging from 8 to 20 pg. Recoveries of As were between 78 and 117%. The precision of the method was better than 5% for all biological matrices examined. Thus, the automated HG-CT-AAS system provides an effective and sensitive tool for analysis of all major human metabolites of iAs in complex biological matrices.