Determination of Lead and Cadmium in Tobacco by Atomic Absorption Spectrometry

A mixed acid composed with nitric acid,hydrogen peroxide and hydrofluoric acid was used to digest tobacco assisted by a microwave digestion system.Lead and cadmium were quantitative determined by transversely heated graphite furnace atomic absorption spectrometry with a deuterium lamp background adjustment system after adding NH4H2PO4 as matrix modifier.This method has good linear relation at the density range of lead 3.5 g/L to 5.0 g/L.Correlation coefficient were 0.997 6 and 0.996 6 respectively.The determination limit were 0.735 g/L and 0.041 g/L,and the recovery coefficient was 98.81% and 92.47%.The established method suitable for routine determination of lead and cadmium in tobacco was proved simple,sensitive and accurate.