ANALYSIS OF BOXY-5,7-DIBROMO-6-HYDROXY-2,3,4-TRICHLOROXANTHONE IN THECOLOR ADDITIVE-D AND ADDITIVE-C RED-NO-27 AND RED-NO-28 (PHLOXINE-B) BY LIQUID-CHROMATOGRAPHY

High-performance liquid chromatography was used to analyse boxy-5,7-di bromo-6-hydroxy-2,3,4-trichloroxanthone (HXCA) in 34 commercial batche s of U.S. certified color additives D&C Red Nos, 27 and 28 (phloxine B ). Thirty-one samples were found to contain HXCA in amounts ranging fr om 0.01 to 0.47% with an average value of 0.12%. These values are one order of magnitude lower than those previously reported for the Japane se counterpart of D&C Red No. 28 (Food Red No. 104). The analyses also revealed significant differences in the level of HXCA across batches from the same manufacturer, The analyses suggest that the presence of HXCA in D&C Red Nos. 27 and 28 may be avoided in the manufacturing pro cess. A theoretical account that could explain the origin of HXCA in t hese color additives is also proposed. (C) 1997 Elsevier Science Ltd.