Quantification of the co-mutagenic beta-carbolines, norharman and harman, in cigarette smoke condensates and cooked foods

Co-mutagenic beta-carbolines, such as norharman and harman, were quantified in mainstream and sidestream smoke condensates of six Japanese brands of c igarettes; and also in 13 kinds of cooked foods, using a combination of blu e cotton treatment and HPLC. Norharman and harman were detected in all the cigarette smoke condensate samples. Their levels in the mainstream smoke ca se were 900-4240 ng per cigarette for norharman, and 360-2240 ng for harman , and in sidestream smoke, 4130-8990 ng for norharman and 2100-3000 ng for harman. These beta-carbolines were also found to be present in all the cook ed food samples, at levels of 2.39-795 ng for norharman and 0.62-377 ng for harman per gram of cooked food. The observed concentrations are much highe r than those found for mutagenic and carcinogenic heterocyclic amines (HCAs ), suggesting that humans are exposed to norharman and harman in daily life to a larger extent than to HCAs. (C) 1999 Elsevier Science Ireland Ltd. Al l rights reserved.