A novel methodology for real-time identification of the botanical origins and adulteration of honey by rapid evaporative ionization mass spectrometry

Abstract

A Rapid Evaporative Ionization Mass Spectrometry (REIMS) method, innovatively combined with electric soldering iron, was developed for the identification of honey authentication and adulteration. Monofloral honey (acacia, rape, chaste, jujube, citrus, medlar), syrup (corn and rice), and simulated polyfloral honey and adulterated syrup-honey samples were evaluated. The classification of botanical origins of honey samples were achieved with a total correct rate of 99.66% through the proposed principal component analysis-linear discriminate analysis (PCA-LDA). The real-time recognition of honey samples was obtained near-instantaneously. The monofloral honey samples (acacia honey, chaste honey, rape honey) could be well distinguished from polyfloral honey (their binary and ternary mixtures). High-value honey (acacia honey) adulterated with low-value honey (rape honey) could be detected from the level of 40% down to 5%. C3 syrup (rice syrup) and C4 syrup (corn syrup) and their adulterated syrup-honey samples in different levels (5, 10, 15, 20, 30, 40%) were also appropriately identified in relation to the adulteration level in a near linear tendency. The detection limit can reach 5–10% adulteration level which can meet the requirement of real adulteration identification. The results of this study indicate that REIMS can serve as a promising rapid and real-time approach for authentication and adulteration analysis of more diverse food samples with the application of contact heating by using a soldering iron.