Preparative Separation Of Components Of The Color Additive Fd-And-C Red No-3 (Erythrosine) By Ph-Zone-Refining Countercurrent Chromatography

The components in 3 g of the commercial color additive FD&C Red No. 3 were separated by pH-zone-refining counter-current chromatography. The main component, 2',4',5',7' -tetraiodofluorescein, and two positional isomeric lower-iodinated subsidiary colors, 2',4',5'-triiodofluorescein and 2',4',7'-triiodoffuorescein, were isolated and characterized by H-1 NMR and chemical ionization mass spectrometry.