Study and validity of C-13 stable carbon isotopic ratio analysis by mass spectrometry and H-2 site-specific natural isotopic fractionation by nuclear magnetic resonance isotopic measurements to characterize and control the authenticity of honey

摘要

Honey samples were analyzed by stable carbon isotopic ratio analysis by mass spectrometry (SCIRA-MS) and site-specific natural isotopic fractionation measured by nuclear magnetic resonance (SNIF-NMR) to first determine their potentials for characterizing the substance and then to combat adulteration. Honey samples from several geographic and botanical origins were analyzed. The delta C-13 parameter was not significant for characterizing an origin, while the (DIH)(I) ratio could be used to differentiate certain single-flower varieties. Application of the official control method of adding a C-4 syrup (AOAC official method 998.12) to our authentic samples revealed anomalies resulting from SCIRA indices that were more negative than -1 parts per thousand (permil). A filtration step was added to the experimental procedure and provided results that were compliant with the natural origin of our honey samples. In addition, spiking with a C-4 syrup could be detected starting at 9-10%. The use of SNIF-NMR is limited by the detection of a syrup spike starting only at 20%, which is far from satisfying. (c) 2006 Elsevier B.V. All rights reserved.