FAAS Determination of Cadmium in Pork Liver with Microwave Assisted Sample Digestion

The minced and homogeneously mixed pork liver sample was digested with conc.HNO3 and H2O2 in the MDS 2003 Microwave Digestor with output power of 650 W,and under gradiently elevated pressure from 0.5 MPa (for 2 min),1.0 MPa (for 2 min) and 1.5 MPa (for 1 min).The transparent and colorless solution obtained was transferred to a 50 mL-volumetric flask and diluted to mark with water after adding 2 mL of HNO3 (1+99).Cadmium(Ⅱ) in the solution was determined by FAAS under the prescribed working condition of the instrument.Detection limit (3s/k) found for the method was 0.20 μg·L-1.Precision and recovery were tested by standard addition method using a same pork liver sample as matrix,values of RSD′s (n=5) found were ranged from 0.66% to 3.25%,and recovery from 94.0% to 116.0%.