Speciation of cationic arsenic species in seafood by coupling liquid chromatography with hydride generation atomic fluorescence detection

A method was developed for determining arsenobetaine (AB), arsenocholine (A C), trimethylarsine oxide (TMAO) and tetramethylarsonium ion (TMA(+)) in se afood products. The arsenic species were extracted from the matrix by metha nol-water and the extracts were quantified by high-performance liquid chrom atography coupled with thermo-oxidation hydride generation atomic fluoresce nce spectrometry (HPLC-thermo-oxidation-HG-AFS). The variables affecting ea ch stage of the methodology were optimized. The analytical features of the method (recovery, precision, limit of detection and linearity range) were c alculated for each arsenical species. The lowest limit of detection was obt ained for TMAO (0.0009 mug g(-1), dry mass), whereas AC was the arsenic spe cies with the highest LOD (0.0063 mug g(-1), dry mass). The precision of th e method varied between 0.7% for AB and 8.4% for TMA(+). The recovery perce ntage was greater than 97% for all species. The proposed procedure was appl ied to reference materials: DORM-2 (Dogfish muscle, National Research Counc il of Canada), NFA-Shrimp and NFA-Plaice (National Food Agency of Denmark). The results were compared with the values obtained by other authors.