Comprehensive analysis of arsenic metabolites by pH-specific hydride generation atomic absorption spectrometry
Comprehensive analysis of arsenic metabolites by pH-specific hydride generation atomic absorption spectrometry
复制标题
DOI：
10.1039/b407388f
复制
发表时间：
2004-01-01
影响因子：
3.4
通讯作者：
Thomas, DJ
中科院分区：
文献类型：
--
作者：
Devesa, V;Del Razo, LM;Thomas, DJ
在多种生物系统中，无机砷（iAs）被代谢产生甲基化砷，其含有+5或+3氧化态的砷。原子吸收光谱法（AAS）结合特定pH生成的砷已被用于选择性分析生物基质中的三价和五价无机砷、一价砷和二甲基砷。我们已经优化了这种方法，允许同时检测和定量的所有相关代谢物的iAs，包括氧化三甲基胂（TMAs（V）O）。优化包括增加用于冷捕集所产生的砷和汞的色谱吸附剂的密度。从冷阱中释放砷的温度梯度的阳离子。这些改进提高了砷化氢、甲基砷化氢、二甲基砷化氢和三甲基砷化氢在AAS检测前的沸点分离度.三价砷和TMAs（V）O中的胂在pH 6时选择性生成。在pH值为1时，三价和五价砷都能生成砷化氢。因此，优化的技术允许分析亚砷酸盐（iAs（III））、砷酸盐（iAs（V））、单甲基亚胂酸（MAs（V））、单甲基亚胂酸（MAs（III））、二甲基亚胂酸（DMAs（V））、二甲基亚胂酸（DMAs（III））和TMAs（V）O。检测限范围从0.14 ng As（对于TMAs O-V）到0.40 ng As（对于iAs（V））。砷的浓度在0.5 - 100 ng范围内与标准曲线呈线性关系。回收率在85%至124%之间。该方法在各种生物基质中的精密度范围为1.0 - 14.5%。使用优化的技术，三价和五价的甲基化和二甲基化砷，但没有TMAs（V）O，已检测到培养的原代人肝细胞暴露于iAs（III）。与此相反，TMAs（V）O被检测到的iAs（III）的体外甲基化的最终产品由大鼠As（III）-甲基转移酶，cyt 19。在用MAs（V）或DMAs（V）处理的小鼠的尿液中也检测到TMAs（V）O。因此，优化的方法提高了生物基质中砷形态分析的效率，提供了一个更全面的图片中的作用，代谢的处置和行动的iAs。
In a variety of biological systems, inorganic arsenic ( iAs) is metabolized to yield methylated arsenicals that contain arsenic in + 5 or +3 oxidation states. Atomic absorption spectrometry ( AAS) coupled with a pH- specific generation of arsines has been used for selective analysis of trivalent and pentavalent inorganic, mono-, and dimethylated arsenicals in biological matrices. We have optimized this method to permit simultaneous detection and quantification of all relevant metabolites of iAs, including trimethylarsine oxide ( TMAs (V) O). The optimization includes increasing the density of the chromatographic adsorbent used for cold- trapping of generated arsines and modi. cation of the temperature gradient for release of arsines from the cold trap. These modifications improve the boiling- point separation of arsine, methylarsine, dimethylarsine, and trimethylarsine before the detection by AAS. Arsines from trivalent arsenicals and from TMAs (V) O are selectively generated at pH 6. At pH 1, arsines are generated from both tri- and pentavalent arsenicals. Thus, the optimized technique permits analysis of arsenite ( iAs (III)), arsenate ( iAs (V)), monomethylarsonic acid ( MAs (V)), monomethylarsonous acid ( MAs (III)), dimethylarsinic acid ( DMAs (V)), dimethylarsinous acid ( DMAs (III)), and TMAs (V) O. The detection limits range from 0.14 ng As ( for TMAs O-V) to 0.40 ng As ( for iAs (V)). Calibration curves are linear over the concentration range of 0.5 - 100 ng As. Recoveries vary between 85 and 124%. The precision of the method in various biological matrices ranges from 1.0 to 14.5%. Using the optimized technique, both trivalent and pentavalent methylated and dimethylated arsenicals, but not TMAs (V) O, have been detected in cultured primary human hepatocytes exposed to iAs (III). In contrast, TMAs (V) O was detected as the final product of in vitro methylation of iAs (III) by rat As (III)- methyltransferase, cyt19. TMAs (V) O was also detected in the urine of mice treated with MAs (V) or DMAs (V). Thus, the optimized method improves the efficiency of arsenic speciation analysis in biological matrices, providing a more comprehensive picture of the role of metabolism in the disposition and action of iAs.