PURIFICATION AND IDENTIFICATION OF SEVERAL SULFONATED AZO DYES USING REVERSED-PHASE PREPARATIVE HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

Reversed-phase preparative HPLC has been successfully used to isolate several sulphonated azo dyes (Acid Red 1, Acid Red 8, Acid Red 106, Ac id Violet 5, Chromotrope 2R, Reactive Orange 16 and Cibacron Brilliant Red 3B-A) from their impurities. The separations were achieved using mobile phases of methanol and ammonium acetate. The major components o f these azo dyes were collected and then identified by electrospray ma ss spectrometry using the characteristic ions [M-2Na](2-), [M-2Na+H](- ) and [M-Na](-). The degree of purification, as measured by electrospr ay mass spectroscopy, was variable. (C) 1998 Elsevier Science B.V. All rights reserved.