Determination of arsenic in foods by flow injection on-line sorption pre-concentration with hydride generation atomic fluorescence spectrometry

Abstract

A method was developed for the determination of total arsenic in foods using flow injection on-line sorption coupled with hydride generation atomic fluorescence spectrometry (HG-AFS) using a cigarette filter as the sorbent material. After reducing As(V) to As(III) by using L-cysteine, the determination of total arsenic was achieved through on-line formation and retention of the pyrrolidine dithiocarbamate arsenic complex (As(III)–PDC) on the cigarette filter, which was packed in the pre-concentration column and total arsenic was determined by HG-AFS. The analytes were eluted with 1.68 mol l−1 HCl from the sorbent material. With consumption of 22 ml of the sample solution, an enrichment factor of 25.6 was obtained at a sample throughput of 11.6 h−1. The detection limits (3 standard deviations) and the precision (relative standard deviation) in foods ranged from 2.5 to 9.9 ng g−1 and from 1.1 to 2.2%, respectively. The method was used to determine arsenic in carrot, mushroom, chicken tissue, cod fish, rice, common carp and shrimp.