Structural Determination of Subsidiary Colors in Commercial Food Blue No. 1 (Brilliant Blue FCF) Product

Abstract

HPLC analysis revealed that five subsidiary colors were present in a commercial Food Blue No. 1 (Brilliant Blue FCF) product. Among them, major subsidiary colors C, D, and E were isolated. On the bases of spectroscopic analyses, their structures were identified as the disodium salt of 2-[[4-[N-ethyl-N-(3-sulfophenylmethyl)amino]phenyl][4-[N-ethyl-N-(4-sulfophenylmethyl)amino]phenyl]methylio]benzenesulfonic acid, the disodium salt of 2-[[4-[N-ethyl-N-(2-sulfophenylmethyl)amino]phenyl][4-[N-ethyl-N-(3-sulfophenylmethyl)amino]-phenyl]methylio]benzenesulfonic acid, and the sodium salt of 2-[[4-(N-ethylamino)phenyl][4-[N-ethyl-N-(3-sulfophenylmethyl)amino]phenyl]methylio]benzenesulfonic acid, respectively.