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The speciation of tellurium was carried out using atomic fluorescence spectrometry as an elementspecific detector in hybridization with liquid chromatography and hydride generation. Good resolution could be obtained by anion-exchange chromatography with complexing agents, using a mobile phase with 8 mM EDTA and 2 mM potassium hydrogenphthalate. Analysis time was less than 6 min. Calibration graphs were linear between 2 and 100 µg l −1 . Detection limits were 0.6 µg l −1 and 0.7 µg l −1 for tellurium(VI) and tellurium(IV) respectively. The method was applied to the speciation of tellurium in drinking water and wastewater samples from different metallurgical industries.

KeyWordsColumn liquid chromatography Atomic absorption spectrometry detection ArsenTc speciatTon Hydride generation Babyfood and fish SummaryThe specTatTon of arsenTc in dTfrerent baby foods and the raw fTsh Tngredients using the direct hybridTsation of liquid chromatography (LC) and hydride generation atomTc absorption spectrometry (HGAAS) Ts described. Good resolutTon of the species, arsenTc{lll), dimethylarsTnTc add (D/VCdk), monomethylarsonTc acid (MMAA) and arsenTc(V) Ts achieved usTng an anion-exchange column wth potassium phosphate as the mobile phase and gradTent elutTon.Arsenobetaine (AsB) is determTned by on-line oxidation usTng peroxydTsulphate and hydrTde generation. The arsenicals were extracted byan enzymatic digestion procedure based on the action of trypsin or pancreatin.Arsenobetaine was the only arsenicspecies detected.The reliabilityof the procedure was checked by analyzing the total arsenic content of the samples by electro thermal atomic absorption spectrometry wth microwave oven digestion and by analyzing a certified reference material. The arsenic content in the baby foods comes from the raw fish in gredients and is highestwhen plaice is used.

The stability of arsenobetaine in baby foods under different experimental conditions is evaluated. Total arsenic was analyzed by electrothermal atomic absorption spectrometry, and the speciation of arsenicals was carried out by coupling liquid chromatography to hydride generation-atomic absorption spectrometry. The highest arsenic levels in the analyzed baby foods corresponded to those containing plaice (2 to 3 microg/g). The speciation data indicated that arsenobetaine, a nontoxic species, was the only arsenical present in the baby foods analyzed at levels between 0.2 and 3 microg/g. Two different procedures for extracting arsenicals from baby foods, involving a water-methanol-chloroform mixture and enzymatic hydrolysis, were tested, and similar results were obtained. Furthermore, the arsenobetaine levels remained unchanged when the baby foods were stored for different times or when the samples were freeze-dried, thus confirming the stability of arsenobetaine and the nonappearance of other arsenic species by interconversion. The reliability of the procedure was checked by analyzing a certified reference material.

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