Determination of mercury in dry fish samples by microwave digestion and flow injection analysis system cold vapor atomic absorption spectrometry

Flow injection analysis system cold vapor atomic absorption spectrometry (FIAS-CV-AAS) preceded by a wet digestion in a microwave oven, as a method for measuring mercury in fish was studied. The digestion process and conditions of the FIAS (carrier concentration: HCl 3% v/v; reducing agent: SnCl2 2% w/v: filling and injection times: 8 and 25 min, respectively; and sample volumes) were optimized. The analytical parameters of the proposed method (detection limit = 7.7 ng/g; precision intraassay = 6.7%; interassay = 14.0%) demonstrates its adequacy and are similar to the ones (detection limit = 19.4 ng/g; precision intraassay = 11.2%; interassay=15.9%) obtained using a conventional wet digestion method with HNO3+H2SO4+V2O5. The accuracy are verified with reference material DORM-1 (dog fish-muscle) NAC-CNRC. Moreover, with the optimized method the risk of losses and contamination is low and it is less time consuming and requires smaller reagent volumes than conventional method. Copyright (C) 1996 Elsevier Science Ltd