Determination of Total Amount of Heavy Metals by Atomic Absorption Spectrometry and Their Speciation Analysis in Tobacco

KeyWord:atomic absorption spectrometry  tobacco  heavy metals  total amount  primary speciation analysis  the second speciation analysis

Abstract:

      Mn£¬Cu,Zn in tobacco were detected by flame atomic absorption spectrometry,and Cd£¬Cr£¬Pb were detected by graphite furance atomic absorption spectroscopy.The method of HNO3-H2O2 microwave digestion was used to obtain total amount of heavy metals.The water soluble speciation of heavy metals were gained by ultrasonic water extraction method for primary speciation analysis,and five species of heavy metals were acquired by Tessier step by step extraction method for the second speciation analysis.The results showed that the linearity was good in detection of six kinds of heavy metals by atomic absorption spectrometry,and the correlation coefficients were not less than 0.998 8 with detection limits of 0.16-3.1 ¦Ìg?L-1.Mn£¬Cu£¬Zn and Cd elements in tobacco were mainly in the form of exchangeable speciation and carbonate bounded speciation while Cr was mainly in residual speciation and Pb was mainly in carbonate bounded speciation and residual speciation.