CONTINUOUS HYDRIDE GENERATION SYSTEM FOR THE DETERMINATION OF TRACE AMOUNTS OF BISMUTH IN METALLURGICAL MATERIALS BY ATOMIC-ABSORPTION SPECTROMETRY USING AN ONLINE STRIPPING-TYPE GENERATOR GAS-LIQUID SEPARATOR/

A method for the determination of trace amounts of bismuth using flow injection and atomic absorption spectrometry with hydride generation w as developed. The introduction of 50 mu l of sample and tetrahydrobora te solution into the HCl and aqueous carriers in a merging zones manif old allows the formation of bismuthine, which is separated from the li quid phase in an on-line stripping-type generator/gas-liquid separator , The calibration graph is linear from 0.1 to 100 ng ml(-1) Bi with a detection limit (3 sigma) of 320 pg ml(-1) Bi (corresponding to 16 pg Bi), The relative standard deviation for 20 replicates varies from 10% for 0.1 ng ml(-1) Bi to 1.9% for 100 ng ml(-1) Bi, with an injection frequency of up to 150 samples h(-1). Ni-II, Co-II, Ag-I, Hg-II, Se-IV and Sb-III interfere, but they can be masked with a thiourea-KI solut ion, The applicability of the proposed method to metallurgical samples was demonstrated by the analysis of certified reference materials.