GFAAS Determination of Cadmium in Rocks from Huguangyan District

The rock sample was digested and heated with a mixture of HF, HNO3 and H2O2, and the content of cadmium in sample solution was determined by GFAAS. The Zeeman correction was used to eliminate the interference of background, NH4H2PO4 was used as matrix modifier, and temperatures selected for ashing and atomization were 500 ℃ and 1 500 ℃ respectively. Linear relationship between values of absorbance and mass concentration of Cd was obtained in the range of 1-20 μg·L-1, with detection limit (3s) of 0.816 3 μg·kg-1. The proposed method was used in the analysis of rocks from Huguangyan district, values of recovery found by standard addition method were in the range of 93.4%-107.2%, and values of RSD′s (n=6) found were in the range of 3.9%-7.2%.