On Methods of Sample Pretreatment in GFAAS Determination of Pb,Cd and Cu in Vivo Caryfish

The sample treatment of caryfish by the method of microwave assisted digestion with HNO3 and H2O2 (method 1#) and the method for dry-ashing (method 2#) were adopted in the GFAAS determination of Pb,Cd and Cu.It was found that precision of method 1# is little bit better than method 2#.Values of RSD′s (n=6) for the 3 elements found by method 1# were in the range of 0.7%-9.4%,while by method 2# were in the range of 2.2%-14.8%.At the same time,the accuracy of method 1# is also better than that of method 2#,as shown by the values of recovery,ranged from 90.2%-94.3% for method 1# and ranged from 78.3%-82.8% for method 2#.On the whole,pretreatment of sample by the microwave assisted acid digestion was preferred to be used in the GFAAS analysis.