Determination of Toxic and Essential Elements in Tilapia Species from the Volta Lake with Inductively Coupled Plasma - Mass Spectrometry

The concentrations of some toxic elements (mercury, lead and arsenic) and some essential elements (cobalt, copper, chromium, manganese, selenium and zinc) in fish obtained from the Volta Lake in Ghana were determined using a rapid, highly sensitive and accurate method. A stepwise digestion procedure using Optima Fisher concentrated nitric acid and hydrogen peroxide was used for complete oxidation of organic tissue. The concentrations of the various elements were measured using an Agilent 7500c quadrupole Inductively Coupled Plasma Mass Spectrometer (ICPMS; Agilent Technologies, Palo Alto, CA) equipped with a dynamic reaction cell and a Cetac ASX-500 autosampler. A total of 62 fish samples covering four different species of tilapia: Oreochromis niloticus, Tilapia zilli, Tilapia dageti and Sarotherodon galilaeus were analyzed for their elemental contents. Results of the study indicate low levels of exposure to arsenic, chromium, cobalt, copper, lead, manganese, mercury, selenium and zinc through consumption of these species of tilapia and do not pose a significant health risk to the individuals and to a greater extent the general population.