Identification of co-mutagenic chlorinated harmans in final effluent from a sewage treatment plant

Abstract

Harman (1-methyl-9 H-pyrido[3,4- b]indole) reacted readily with sodium hypochlorite in an aqueous medium to give the mono-chlorinated derivatives, which reportedly have greater co-mutagenic activity than harman in the presence of o-toluidine toward Salmonella typhimurium TA 98 with S9 mix. Mono-chlorinated harmans were detected by concentration using blue rayon (BR) and GC/MS analysis in the final effluent from a sewage treatment plant in Shizuoka, Japan. The amounts adsorbed for 24 h were 1–45 ng/g BR for mono-chlorinated harman and 110–730 ng/g BR for harman.