GAS-CHROMATOGRAPHIC MASS-SPECTROMETRIC ANALYSES OF UNKNOWN ANALYTICALRESPONSE IN IMPORTED FAVA BEANS - 4-CHLORO-6-METHOXYINDOLE

A halogenated unidentified analytical response (UAR) was encountered i n a number of imported Fava bean samples during the Food and Drug Admi nistration's routine pesticide-monitoring program, Gas chromatographic /mass spectrometric (GC/MS) analyses identified the halogenated compon ent as 4-chloro-6-methoxyindole, a naturally occurring promutagen in F ava beans that has been linked to incidents of gastric cancer. Data fr om electron impact, positive and negative chemical ionization, collisi on-induced dissociation, and deuteration studies of this compound are presented, along with GC retention time data.