
Total and inorganic mercury determination in fish tissue by flow injection cold vapour atomic fluorescence spectrometry
2010; Taylor & Francis; Volume: 90; Issue: 9 Linguagem: Inglês
10.1080/03067310902871729
ISSN1029-0397
AutoresGabriel Gustinelli Arantes de Carvalho, Mário A. Feres, José Roberto Ferreira, V. H. Kennedy,
Tópico(s)Heavy metals in environment
ResumoA simple and reliable method for Hg determination in fish samples has been developed. Lyophilised fish tissue samples were extracted in a 25% (w/v) tetramethylammonium hydroxide (TMAH) solution; the extracts were then analysed by FI-CVAFS. This method can be used to determine total and inorganic Hg, using the same FI manifold. For total Hg determination, a 0.1% (w/v) KMnO4 solution was added to the FI manifold at the sample zone, followed by the addition of a 0.5% (w/v) SnCl2 solution, whereas inorganic Hg was determined by adding a 0.1% (w/v) L-cysteine solution followed by a 1.0% (w/v) SnCl2 solution to the FI system. The organic fraction was determined as the difference between total and inorganic Hg. Sample preparation, reagent consumption and parameters that can influence the FI-CVAFS performance were also evaluated. The limit of detection for this method is 3.7 ng g−1 for total Hg and 4.3 ng g−1 for inorganic Hg. The relative standard deviation for a 1.0 µg L−1 CH3Hg standard solution (n = 20) was 1.1%, and 1.3% for a 1.0 µg L–1 Hg2+ standard solution (n = 20). Accuracy was assessed by the analysis of Certified Reference Material (dogfish: DORM-2, NRCC). Recoveries of 99.1% for total Hg and 93.9% inorganic Hg were obtained. Mercury losses were not observed when sample solutions were re-analysed after a seven day period of storage at 4°C.
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