Ultrasonic Extraction-GF-AAS Determination of Available Cadmium in Soil

A method for the determination of available cadmium in soil by GF-AAS was proposed in this paper. The samples were extracted ultrasonically at (25±2) ℃ for 15 min with DTPA extracting solution. The temperatures of ashing and atomization were set at 500 ℃ and 1 800 ℃ respectively. Under the optimal experimental conditions, linear relationship between values of absorbance and mass concentration of cadmium was kept in the range of 0.05-3.0 μg·L-1, with detection limit (3s/k) of 0.5 pg. The proposed method was applied to the determination of cadmium in two CRM′s (GBW 07459 and GBW 07461), giving results in consistency with those obtained by the GB method (GB/T 23739-2009) with values of RSD′s (n=5) of 5.2% and 2.6% respectively.