A sensitive method for free amino acids analysis by liquid chromatography with ultraviolet and mass spectrometric detection using precolumn derivatization with diethyl ethoxymethylenemalonate: application to the honey analysis.

In case of some foods and drinks, their amino acid content is demonstrated to correlate with the botanical and/or geographical origin of the plant. In present work a method for amino acid analysis in honey was developed and validated. The method consists of sample preparation (including solid phase extraction), derivatization with diethyl ethoxymethylenemalonate and liquid chromatographic analysis. Full separation of 23 amino acids was achieved. All steps were extensively studied and optimized for analytical performance. Although ultraviolet (UV) detection provides sufficient sensitivity for honey analysis, all the steps of the method were designed to be compatible with mass spectrometric (MS) detection. The developed method has been applied to analysis of nearly 200 Estonian honey samples.