SIMULTANEOUS DETERMINATION OF ARSENIC(III) AND ANTIMONY(III) BY OZONE-INDUCED GAS-PHASE CHEMILUMINESCENCE

A combined hydride-generation/gas-phase chemiluminescence (HG-GPCL) me thod for the determination of arsenic(III) and antimony(III) by using a conventional luminometer is proposed. The method was optimized in te rms of the type of reaction chamber, the instrumental settings, and th e hydride generation and reaction conditions used. It provides a linea r response to As(III) and Sb(III) above a concentration of 0.05 and 0. 50 mg L(-1), respectively, with a relative standard deviation of simil ar to 3% for both species. Arsenic and antimony can thus be determined simultaneously by (1) their differential effect on the signal obtaine d with an optical filter placed between the reaction chamber and detec tor, or (2) the difference between the peak height/peak area ratio of the transient signal for their hydrides. Both procedures were applied to the determination of arsenic and antimony in various synthetic aque ous samples with good accuracy and precision. The effect of potential interferences including anionic and hydride-forming inorganic species was investigated.