2012 Volume 29 Issue 2 Pages 77-
A flow injection-hydride generation-atomic fluorescence spectrometry system has been developed for monitoring arsenite and arsenate in aqueous samples. The system involves injection of a 120-µL water sample in a carrier stream, mixing with 1.0 M phosphate buffer or 3 M HCl followed by 3.0% alkaline reducing agent NaBH4, passing through a mixing coil and feeding into a gas liquid separator with Ar carrier gas. The generated arsenic trihydride (AsH3) was fed to an atomizer by the carrier gas and the fluorescence intensity monitored using a photomultiplier tube. Under optimized conditions, the detection limit was 0.2 µg/L with a linear range of 0.5–300 µg/L. A distinction between As(III) and As(V) measurements was possible with a sampling frequency of 30/h. Repeatability ( n = 20) for As(III) and total arsenic was 1.7 and 1.0%, respectively, for standard mixture solutions of [10 µg/L As(III) + 10 µg/L As(V)].