Analysis of Water-Soluble Vitamins in Honey by Isocratic RP-HPLC

Abstract

An isocratic RP-HPLC method has been developed for the identification and quantification of water-soluble vitamins in honey. The mobile phase tested was an aqueous solution of sulphuric acid and the detection was carried out simultaneously by UV and fluorescence. The separation of vitamins C (l-ascorbic acid), B1 (thiamine), B3N (nicotinamide), B3H (nicotinic acid), B5 (d-pantothenic acid) and B6 (pyridoxine) is achieved in these conditions in 15 min. The addition to the mobile phase of methanol 2 % v/v reduced significantly the analysis time in the separation of these vitamins up to 10 min. Moreover, in presence of a cationic surfactant hexadecyltrimethylammonium bromide (CTAB) in the mobile phase, the separation of vitamin C, B1, B3N, B3H, B2 (riboflavin) and B6 is possible in 6 min. The combination of both mobile phases, H2SO4/methanol and H2SO4/methanol/CTAB, has been applied to the analysis, in isocratic mode, of several monofloral honeys (rosemary, thyme, lavender, chestnut, echium) and a honeydew honey in a short time analysis.