A sequential injection lab-at-valve (SI-LAV) platform for hydride generation atomic absorption spectrometry (HG-AAS): on-line determination of inorganic arsenic

摘要

A novel automatic low-cost sequential injection lab-at-valve (SIA-LAV) system has been developed for inorganic arsenic determination coupled with hydride generation atomic absorption spectrometry (HG-AAS). The proposed manifold includes an integrated gasa€“liquid separator/reaction chamber (GLS-RC) which was attached to one port of a conventional six-port multiposition selection valve. The arsine vapour is generated by injecting reductant NaBH4 into the GLS-RC, minimizing its dispersion and possible losses. All critical parameters affecting the efficiency of the system were studied and optimised. For 3.0 mL sample consumption the detection limit was 0.05 ??g La?’1 and the precision expressed as RSD was 3.2%. The proposed method was evaluated in comparison with a reference flow injection HG method and applied for arsenic determination in environmental water samples. The recovery was estimated by spiking the samples and it ranged from 95.5% up to 102.5% for both As(III) and As(V).