You are here:
ADVANCED APPROACHES TO ARSINE ATOMIZATION FOR AS SPECIATION BY CRYOFOCUSING WITH ATOMIC ABSORPTION AND ATOMIC FLUORESCENCE DETECTORS
Citation:
DEDINA, J., T. MATOUSEK, M. SVOBODA, M. STYBLO, AND D. J. THOMAS. ADVANCED APPROACHES TO ARSINE ATOMIZATION FOR AS SPECIATION BY CRYOFOCUSING WITH ATOMIC ABSORPTION AND ATOMIC FLUORESCENCE DETECTORS. Presented at 9th Rio Symposium on Atomic Spectrometry, Barquisimeto, VENEZUELA, November 05 - 10, 2006.
Description:
Human metabolism of inorganic arsenic (iAs) yields methylated arsenicals that contain arsenic in +3 or +5 oxidation state. Trivalent methylated arsenicals are significantly more toxic than their pentavalent counterparts. Therefore, determination of tri- and pentavalent forms of methylated arsenicals is a key issue for arsenic toxicology. The hydride generation-cryoseparation technique involves trapping of volatile As hydrides under liquid nitrogen temperature and their subsequent volatilization and separation according to boiling points and chromatographic properties by gradual heating. The main advantage of this technique is that analysis can be performed directly without a sample pretreatment. This is especially important when dealing with extremely unstable trivalent methylated species.
A system for selective generation is presented: either exclusively trivalent or both tri- and pentavalent forms are generated depending on reaction conditions (pH of reaction media and the presence of L-cysteine as a reductant/ reaction modifier). A simple automated cryoseparation unit was developed to solve the crucial problem of cryoseparation technique - laboriousness.