FAAS Determination of Traces of Zn,Ca,Cu in Black Colored Food

The sample was pretreated both by wet digestion method and dry ashing method,and the contents of Zn,Ca and Cu in the sample solution were determined by FAAS.As shown by the experimental results,the linearity range for Ca was between 0.10-10 mg·L-1,and for both Zn and Cu were between 0.05-5 mg·L-1.As a conclusion of the comparative study,the wet digestion method was preferred in the pretreatment of samples for higher sensitivity and accuracy.The proposed method was used in the analysis of black agaric and black rice,giving values of recovery of 98.93%,99.80%,102.20% (in black agaric) and 102.90%,96.35%,97.28% (in black rice);with values of RSD′s (n=10) less than 2%.