A comprehensive analysis of 13C isotope ratios data of authentic honey types produced in China using the EA-IRMS and LC-IRMS

In the current study, we have comprehensively analyzed different kinds of pure honey which was produced in various areas in China according to delta C-13-EA -IRMS (AOAC method 998.12) and delta C-13-LC-IRMS (proposed by the Intertek laboratory in Europe) methods. As for the delta C-13-EA -IRMS method, the study was confirmed that the C4 sugar of all authentic honey samples was qualified. Further inter-laboratory comparison experiments using the delta C-13-LC-IRMS method found that all authentic honey samples had Delta delta C-13 (parts per thousand) values within the naturally occurring range of +/- 1 parts per thousand for Delta delta C-13 (parts per thousand) fru-glu. However, about 70% samples had Delta delta C-13 (parts per thousand) values outside the range of +/- 2.1 parts per thousand for Delta delta C-13 (parts per thousand) max., indicating that a large proportion of pure honey in China can't pass the delta C-13-LC-IRMS test, although these honeys were extracted from unadulterated sources. Based on the present findings, we consider that the delta C-13-LC-IRMS method is not appropriate to reliably detect adulterated honeys with C3 sugars in China.