Simultaneous determination of arsenic selenium and antimony species in biological and environmental materials by atomic spectrometry
Methods for the simultaneous determination and speciation of arsenic, selenium and antimony in complex matrices involving inductively coupled plasma optical emission spectrometry (ICP-OES), and inductively coupled plasma mass spectrometry (ICP-MS) coupled with high performance liquid chromatography (HPLC) were developed and successfully applied to the analyses of various types of environmental and biological samples.
A flexible internal standardization procedure for ICP-OES has been developed that extends the choices of possible internal standards and has the potential for greater accuracy than traditional internal standardization based on one standard. This method is based upon the visualization by principal component analysis of the similarity of matrix-induced behavior among emission lines. For a given analytical line, more choices of internal standards are provided from composite spectral lines created by combining real spectral lines in such a way as to integrate their characteristic behaviors. The method was applied with satisfactory results to the determination of As, Sb and Se in solutions which modeled plant and food sample digests to compensate for the matrix effect.
A method for the simultaneous determination of As, Sb and Se by the multimode sample introduction system coupled to ICP-OES has been developed. Reaction mechanisms for sample treatment and hydride generation are proposed to account for some unusual observations.
In order to study urinary arsenic and selenium metabolism and interactions in the human body, a procedure for the simultaneous determination of six Se species and six As species in human urine by HPLC-ICP-MS has been developed.
Positive associations between As intake and urinary Se metabolites, Se intake and urinary As metabolites were found. As and Se interactions may increase the mobility of both species in human tissue or blood, and as a result, more As and Se may be excreted. The competition for methyl groups between As and Se species changes the distribution of As and Se metabolites in human urine. The excretion of methylated species are delayed. The formation of monomethylated species is enhanced while that of multimethylated species is inhibited when both As and Se are ingested.