The degradation of tryptophan during paper chromatography with observations on some metabolites of tryptophan

The possible degradation of tryptophan and seven of its metabolites during and after paper chromatography with n-butanol-acetic acid-water has been investigated. It has been found that extensive degradation results from developing and drying the chromatograms at temperatures over 27° and storing them in room light for extended periods before the second development. Lesser amounts of degradation were found after limited exposure of compounds to ultraviolet light between developments and occasionally with the use of unwashed paper. Procedures to eliminate degradation have been described.