RP-HPLC determination of water-soluble vitamins in honey

The assessment and validation of reliable analytical methods for the determination of vitamins in sugar-based matrices (e.g. honey) are still scarcely explored fields of research. This study proposes and fully validates a simple and fast RP-HPLC method for the simultaneous determination of five water-soluble vitamins (vitamin B2, riboflavin; vitamin B3, nicotinic acid; vitamin B5, pantothenic acid; vitamin B9, folic acid; and vitamin C, ascorbic acid) in honey. The method provides low detection and quantification limits, very good linearity in a large concentration interval, very good precision, and the absence of any bias. It has been successfully applied to 28 honey samples (mainly from Sardinia, Italy) of 12 different botanical origins. While the overall amount of the analytes in the samples is quite low (always below 40 mg kg−1), we have observed a marked dependence of some of their concentrations (i.e. vitamin B3 and vitamin B5) and the botanical origin of the honey. This insight might lead to important characterization features for this food item.