Abstract:

A ratio spectra derivative spectrophotometric method was developed for the simultaneous determination of pcoumaric acid and ferulic acid. p-coumaric acid and ferulic acid dissolved in either ethanol, water or an ethanol aqueous solution with pH adjusted to be 2.0 exhibited stable maximum absorption at 308 nm and 320 nm, respectively. Spike recoveries for both acids were within the range of 93.40%－103.34%. In the determination of p-coumaric acid and ferulic acid by this method in phenolic acids extracted from sugar cane residue, the presence of other substances having an obvious spectral absorption at wavelengths close to 308 nm led to a large error of p-coumaric acid determination but accuracy determination results of ferulic acid were obtained. This method provides an approach to the effective determination of p-coumaric acid and ferulic acid, between whose spectra, there is a large overlap.

Key words: ratio spectra derivative spectrophotometry, p-coumaric acid, ferulic acid