The nitric acid was purchased from Fluka,Germany. The flame atomic absorption spectrometry from NovAA-400, Analytikjena AG, Germany.The fish samples were collected from local market in Tripoli, Libya (Table 1) and cleaned then washed with distilled water. Different dried tissues (bone, skin, flesh and tail) were dried at room temperature for two weeks. The dried tissues were digested as following: 1.0 g of each was dissolved in 1 M nitric acid (10 ml), boiled to complete the dissolution and filtrated. The obtained precipitate was washed with nitric acid (1 M) and transferred to 25 ml volumetric flask and fill up to the level with de-ionized water.