FAAS Determination of Heavy Metal Elements Pb,Cd and Ni in Traditional Chinese Medicines

Three heavy metal elements,Pb,Cd and Ni in 5 traditional Chinese medicines (TCM′s) were determined by FAAS.The samples were digested with a mixed solution of conc.HNO3 and con.HClO4(4+1).The working conditions of the instrument were described in detail,and wavelengths of 283.3,228.3,232.0 nm were selected as analytical lines for the determination of Pb,Cd and Ni respectively.The proposed method was used in the analysis of 5 kinds of TCM′s,i.e.,galangal,licorice root,bulbus fritillariae cirrhosae,centipede and bombyx batryticatus,for the contents of Pb,Cd and Ni.The values of recovery of Pb,Cd,and Ni found by standard addition method were in the ranges of 7.8%-104.0%,93.5%-104.0% and 95.6%-103.0% respectively with values of RSD′s less than 2.5%.