Determination of heavy metals in crayfish by ICP-MS with a microwave-assisted digestion treatment.

Contamination of the American red crayfish, from the Guadiamar riverside, is due to the disastrous toxic spill that occurred on 25 April 1998 in the mining area of Aznalcóllar-Los Frailes, Spain. A high concentration of heavy metals in the waters from the mine pool and their spill to the river Guadiamar was the cause of the destruction of a great number of animal and vegetable organisms. An ICP-MS method for the total determination of heavy metals (Cu, Zn, Pb, and Cd) in whole bodies of American red crayfish (Procambarus clarkii) was used. Metals were extracted from the matrix in a closed-vessel microwave digestion system with nitric acid and hydrogen peroxide. A study of the uncertainty of the method for the determination of metals was carried out; at a concentration of 5 microg/L, the uncertainty was below 34%.