Abstract
Chemical and biological assays showed that wool filters containing mixtures of commercially available polyethylenimines (PEI) and quaternary ammonium compounds (QUAT) selectively removed proportions of the biologically active volatile constituents of cigarette smoke. The action of the QUAT was synergistic in that it enhanced the performance of PEI filters but, alone, was ineffective in retaining volatile components. Only water-soluble QUATs with one long hydrocarbon chain (> 10 C-atoms) attached to nitrogen were effective. The best removal efficiencies were obtained with a PEI/QUAT ratio in the range 0.8-1.0 and 5-10 % by weight of each additive on the filter material. Analyses of puffs at stages along the tobacco column indicated that the treated filters retained their effectiveness from the first to the last puffs. The treated filters significantly increased the pH of the mainstream smoke.