Determination of Amino Acids in Bee Products by Diethyl ethoxymethylenemalonate Derivatization Using LC-ESI-MS/MS

Abstract

Amino acid content of honey and royal jelly has been used for the product authentication, geographical and botanical origin evaluation, indication of freshness and nutritional value. In this thesis analytical method was tested and improved for analysis of the concentration of free amino acids in Vietnamese monofloral (Robusta coffee) honey and Royal Jelly by derivatization with diethyl ethoxymethylenemalonate (DEEMM) using liquid chromatography coupled to mass spectrometry (LC-MS/MS). The derivatization proceeds under aqueous conditions and is sufficiently fast reaction for most amino acids. Limits of quantitation at ng g-1 level were achieved for most amino acids. The method has good repeatability and recovery in general. Determined amino acid contents agree, in general, well with literature findings in different honey and royal jelly samples. The differences found may be indicative of botanical/geographical origin of these bee products.