OPTIMIZED SEPARATION OF SCOPOLETIN AND UMBELLIFERONE AND CIS-TRANS ISOMERS OF FERULIC AND PARA-COUMARIC ACIDS BY REVERSE-PHASE HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

A systematic optimization strategy for reverse-phase h.p.l.c. is used to produce complete separation of all components of a mixture containing two coumarins, umbelliferone and scopoletin, and the cis-trans isomers of two cinnamic acids, p-coumaric and ferulic. A series of experiments gives retention time data for each of these substances in four citric acid-buffered mobile phases. A mathematical model fitted to this data gives model parameters that provide the basis for a window diagram of relative retentions vs. mobile phase pH. The window diagram gives an estimate of the mobile phase pH required for optimum separation. © 1979.