MOVABLE REDUCTION BED HYDRIDE GENERATION SYSTEM AS AN INTERFACE FOR CAPILLARY-ZONE-ELECTROPHORESIS AND INDUCTIVELY-COUPLED PLASMA-ATOMIC EMISSION-SPECTROMETRY FOR ARSENIC SPECIATION ANALYSIS

Hydride generation can significantly improve the detection limits for a number of hydride-forming elements with atomic spectrometric determi nation, In order to harmonize the microliter level eluates from capill ary electrophoresis and the milliliter sample volume commonly needed i n ICP-AES, a specially designed technique, 'movable reduction bed hydr ide generation? has been developed, which is simple to operate and car ries out the hydride generation for micro-sample volume without the us e of a gas-liquid separator or the addition of an acid dehydrator. The technique can be used to convert arsenic compounds from capillary zon e electrophoresis (CZE) separation to corresponding volatile hydrides followed by ICP-AES analysis. The separation characteristics of arseni c species by CZE are presented, including the optimization of experime ntal parameters such as pH, concentration of buffer solution, as well as sample injection volume. The RSDs of peak area for four arsenic spe cies range from 1.9 to 11.7%, The detection limits for As-III, disodiu m methylarsonate and As-V are 0.32 mu g ml(-1), and 0.35 mu g ml(-1) f or dimethylarsinic acid.