Abstract: The sample was dissolved an appropriate acid mixture and evaporated to dryness.The residue was taken up with a phthalate buffer solution of pH 3.0 Tin(Ⅳ) and lead(Ⅱ) in the sample solution were separated by co-precipitation with thioacetamide and titanium trichloride.The precipitate obtained was dissolved with conc.HCl,and an aliquot of the sample solution in HCl(1+9) was used for AAS determinations separately.Tests for precision and recovery were made,giving values of RSD′s (n=6) in the ranges of 0.74%-0.96% (for Sn),0.64%-1.41% (for Pb),and values of recovery in the ranges of 98.1%-100.9% (for Sn),97.6%-100.6% (for Pb).