FAAS Determination of Lead and Copper in Whitening Cosmetics with Microwave Assisted Sample Digestion

Samples of whitening cosmetic were digested with mixture of con. HNO3 and H2O2 for cream and liquor, and with mixture of con. HNO3-H2O2-HF for powder. Contents of Pb and Cu in the sample solutions obtained were determined by FAAS. Under the optimized conditions, linear relationships between values of absorbance and mass concentration of Pb and Cu were obtained in the ranges within 9.0 mg·L-1 and within 11.0 mg·L-1 respectively. Values of detection limits (3s) found were 21.8 μg·L-1 for Pb and 16.2 μg·L-1 for Cu. Test for recovery was made by standard addition method on the base of substantial samples, giving values of recovery in the ranges of 98.0%-102.5% for Pb and 96.7%-105.0% for Cu.