Antimony determination and speciation by multisyringe flow injection analysis with hydride generation-atomic fluorescence detection

Abstract

A new analytical procedure for determination of inorganic antimony and speciation of antimony(III) and antimony(V) is presented. For this purpose, a software-controlled time-based multisyringe flow injection system, which contains a multisyringe burette provided with a multi-port selection valve, was developed. Hydride generation-atomic fluorescence spectrometry was used as a detection technique. A 0.3% (w/v) reducing sodium tetrahydroborate solution, hydrochloric acid (2 M), an antimony solution and a pre-reducing solution of 10% (w/v) KI and 0.3% (w/v) ascorbic acid are dispensed simultaneously into a gas–liquid separation cell with further propulsion of the reaction product into the flame of an atomic fluorescence spectrometer using argon flow. A hydrogen flow was employed to support the flame. The linear range and the detection limit (3s b/S) of the proposed technique were 0.2–5.6 μg l −1 and 0.08 μg l −1, respectively. A sample throughput of 18 samples per hour (corresponding to 80 injections per hour) was achieved. The relative standard deviation for 18 independent measurements was 4.6%. This technique was validated by means of reference solid and water materials with good agreement with the certified values. Satisfactory results for speciation of Sb(III) and Sb(V) by means of the developed technique were obtained.