Abstract: In this study,a new method for processing biological samples was developed by modifying EPA200.11 and EPA6020 methods.The concentrations of 14 trace elements(Cr,Co,Ni,As,Se,Cd,Pb,Zn,Cu,Mo,Ag,Be,V,Ge)in 4 raw and cooked fish tissues were determined by ICP-MS.The results showed that the concentrations of Pb,Cd and Cu in the tested samples were all lower than the limited values listed in GB2762-2012.In addition,the EWI values of Pb,Cd and Se elements in raw and cooked fish tissues were calculated.The results turned out that the EWI values of Pb and Cd elements were lower than PTWI values of these elements.It revealed that the cooked and raw fish did not pose any health risk for the consumers.The results also showed that Ge,As,Co,Mo,Se(P<0.0500)and V(P>0.0500)were the principal component elements by using SPSS11.5.Besides,the principal component elements in the raw fish tissues were compared with these elements in the cooked fish tissues.It was concluded that cooking was an important means of reducing the concentrations of hazard elements in fish tissues.

Key words: EPA methods, ICP-MS, cooked fish, raw fish, trace elements, principal component analysis