Multichannel coulometric detection coupled with liquid chromatography for determination of phenolic esters in honey

A method for the determination of phenolic esters in different varieties of honey was developed. The substances were separated by RP-HPLC. A coulometric electrode-array system with sixteen electrodes arranged in series and set at increasing potentials (300-900 mV) was used for electrochemical detection of the compounds. Chromatographic peaks for methyl 4-hydroxybenzoate, methyl vanillate, methyl syringate, trans-p-methyl coumarate and trans-methyl ferulate were identified. The content of the esters varied between 1.3 and 5044 micrograms per kg of honey with detection limits of 0.1-1.0 microgram per kg of honey (S/N = 3). The method described is a sensitive assay to differentiate between rape honey and other varieties.