SIMULTANEOUS DETERMINATION OF TOXIC ARSENIC AND CHROMIUM SPECIES IN WATER SAMPLES BY ION CHROMATOGRAPHY INDUCTIVELY-COUPLED PLASMA-MASS SPECTROMETRY

A method based on ion chromatography in conjunction with inductively c oupled plasma mass spectrometry is presented for simultaneous determin ation of toxic chromium and arsenic species: Cr(VI), As(III) and As(V) using KNO3 at pH 9.8 as eluent. Cr(III), dimethylarsinate, monomethyl arsonate, arsenobetaine and arsenocholine did not interfere with the a nalysis, since Cr(III) was eliminated before analysis and As species w ere separated from the analytes. The advantages and disadvantages of g radient and isocratic elution in trace speciation analysis by ion chro matography are discussed. With the method described, Cr(VI), As(III) a nd As(V) could be analyzed at a concentration level of 0.5 mu g/l. An application of the proposed method is presented for waste water and dr inking water analysis. (C) 1997 Elsevier Science B.V.