Microwave digestion of fish tissues and determination of Cu, Se and Hg by atomic absorption spectrometry

A microwave digestion procedure has been developed for the accurate determination of Cu, Se and Hg in fish tissues (muscle and liver). Digestion parameters such as the time and power of the microwave system, the composition of the digestion solution and the adjustment of oxidation slate of Se and Hg prior to analysis have been studied. For Se and Hg, a comparison of different analytical techniques was done. The efficiency of both the digestion and the analytical procedures was tested by using certified reference materials (CRM). The determination of Cu, Se and Hg in fish tissues from Ramsey Lake (Sudbury, Canada) indicated that Cu and Se were more efficiently accumulated in liver whereas Hg had more affinity for muscle tissues. The differences in tissue concentrations of the three elements could be partially explained by fish feeding habits.