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

Harman (1-methyl-9H-pyrido[3,4-b]indole) reacted readily with sodium hypoch lorite 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-chlori nated harmans were detected by concentration using blue rayon (BR) and GC/M S 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-chlorinate d harman and 110-730 ng/g BR for harman. (C) 2001 Elsevier Science B.V. All rights reserved.