Preconcentration and determination of inorganic arsenic using a multisyringe flow injection system and hydride generation-atomic fluorescence spectrometry

A new multisyringe flow injection system for inorganic arsenic determination at trace levels by hydride generation-atomic fluorescence spectrometry (HGAFS) is presented. Preconcentration on a solid-phase was carried out using a column packed with an anion-exchange resin (Amberlite IRA-410). The reagents are dispensed to the system using a multisyringe burette coupled with two multi-port selection valves. Different parameters were changing in order to make the system as effective as possible. An analytical curve was obtained for arsenic determination between 50 and 2000 ng l(-1). This new approach improved five times the sensitivity over a MSFIA-HGAFS technique developed previously by the authors. Detection limit of the proposed technique was (3sigma(b)/S) of 30 ng l(-1). The relative standard deviation (R.S.D.) of As at 1 mug l(-1) was 4.8% (n = 7). A sample throughput of 10 h(-1) has been achieved. The proposed method has been applied to different reference solid and water materials with satisfactory results. (C) 2004 Elsevier B.V. All rights reserved.