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% vv; reducing agent: SnCl2 2% wv: filling and injection times: 8 and 25 min, respectively; and sample volumes) were optimized. alytical 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.