Determination of Residual Tin in Officinal Polylactic Acid by GFAAS

The sample polylactic acid was digested with the mixture of HNO3 and H2SO4,and the residual Tin in the prepared solution was then determined by GFAAS.Ascobic acid was selected as a matrix modifier.DL of the method was 0.23 mg·L-1 and linearity of the calibration curve was ranged in 1-10 mg·L-1 with corrlelation coefficient 0.996 8.Recovery of the method was 97.1% and interday RSD was 6.9%.The proposed method met requirements of Chinese Pharmacopoeia-2005 for detection of residual Tin in auxiliary material of the drug.