Determination of mannose in honey by isotope dilution gas chromatography mass spectrometry

A method for the determination of mannose in honey by isotope dilution gas chromatography-mass spectrometry（GC-MS）was established，using［13C6 ；D7］-D-mannose as the isotope internal standard. The gas chromatographic separation conditions and mass spectrometric parameters of mannose and its internal standard were optimized. After the honey sample was dissolved in 70% ethanol aqueous solution，the isotope internal standard was spiked. The sugar components in honey were derivatized by two-step derivatization method. Firstly， 2.5% hydroxylamine hydrochloride pyridine solution was added for oximation derivatization，and then N，O-bis （trimethylsilyl）trifluoroacetamide（BSTFA）was added for silylation derivatization. Finally，in the representative acacia honey，rape honey，vitex honey，and linden honey，mannose was qualitatively and quantitatively detected by GC-MS. The results showed that the detection limit of mannose was 6 mg/kg，and the limit of quantification was 20 mg/kg. The average recoveries of mannose were 66.1%-91.7% at the spiked levels of 20， 40 and 200 mg/kg，and the relative standard deviation was less than 20%. The method is applicable for the determination of mannose in different types of honey. © 2022, Youke Publishing Co.,Ltd. All rights reserved.