Spectrophotometric Determination of Cadmium in Cigarette Materials

A method to determine trace cadmium in cigarette materials with spectrophotometry was established.The trace cadmium in cigarette materials was digested with concentrated HNO₃ and H₂O₂, then enriched and separated by solid phase extraction with strong anion exchange resin cartridge, and determined with spectrophotometry at 520 nm by using 6-bromo-2-benzothiazolyl diazoaminoazobenzene as color reagent in pH10 sodium borate-sodium hydroxide buffer solution medium in the presence of TritonX-100.The molar absorptivity of the reaction system is 1.92×10⁵ L·mol^-1·cm^-1.The RSD and recovery of the method were 2.2%-2.8% and 94%-105%, respectively.The results determined with this method agreed with that of atomic absorption.