FAAS Determination of Copper and Calcium in Protein Powder with Microwave Assisted Sample Digestion

Sample of protein powder was digested with HNO3 in a closed vessel,heated at 180 ℃and under a pressure of 3.0 MPa by using microwave sample digestor.The solution obtained was used for FAAS determination of Cu and Ca.The working conditions of the instrument were described in detail,and wavelengths of 324.75,422.7 nm were selected as analytical spectral lines for the determination of Cu and Ca respectively.It was found that precision of results obtained by microwave assisted sample digestion method was better than those obtained by the dry ashing method.The proposed method was used in the determination of contents of Cu and Ca in protein powder.Values of recovery of Cu and Ca found by standard addition method were 100.5% and 99.4% respectively with values of RSD′s (n=7) less than 1.0%.