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 2000ngl(-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 30ngl(-1). The relative standard deviation (R.S.D.) of As at 1mugl(-1) was 4.8% (n=7). A sample throughput of 10h(-1) has been achieved. The proposed method has been applied to different reference solid and water materials with satisfactory results.