High Performance Liquid Chromatographic Determination of Intermediates and Two Reaction By-Products in FD&C Red No. 40: Collaborative Study

Abstract

Abstract Nine laboratories participated in a collaborative study of an ion exchange high performance liquid chromatographic procedure for determining the intermediates and 2 reaction by-products in FD&C Red No. 40: cresidine sulfonic acid (CSA), Schaeffer’s Salt (SS), 4,4’-(diazoamino)bis(5-methoxy-2-methylbenzenesulfonic acid) (DMMA), and 6,6’-oxybis(2- naphthalenesulfonic acid) (DONS), respectively. The repeatability and reproducibility standard deviations (absolute) found in the study were 0.012 and 0.019 for CSA at the 0.2% level, 0.004 and 0.006 for DMMA at the 0.1% level, 0.067 and 0.087 for DONS at the 1% level, and 0.015 and 0.020 for SS at the 0.3% level, respectively. The method has been adopted official first action.