Abstract
In the simple determination of vitamin A in margarine which has been reported by the authors, yellow AB and OB were found to become pheoylazo-acetaldehyde-β-naphthylimid or ο-tolylazo-acetaldehyde-β-naphthylimide by condensing with acetaldehyde and to be removed easily by acetic acid. Various phenylazo-and ο-tolylazo-aldehyde-β-naphthylimides were prepared from yellow AB or OB, and their chemical properties were listed.
