B-HIVE: Beeswax hydrogen isotopes as validation of environment. Part I: Bulk honey and honeycomb stable isotope analysis

Stable isotope analysis is an established method for detecting honey adulteration. We extend its application to include honey and honeycomb region-of-origin assignment using hydrogen (δ2H) and oxygen (δ18O) isotopes. We observed that liquid honey δ2H and δ18O values had the potential to change because of water absorption and H atom exchange between sugars and water vapour. This suggested that liquid honey has limited use for geo-location, because specimens will record analysis location humidity. Paired liquid honey and honeycomb δ2H values were significantly correlated; therefore, we propose using wax δ2H values for region-of-origin assignment. We observed significant correlations between beeswax δ2H values and both mean annual precipitation and tap water δ2H values predicted for hive locations, suggesting that geographical variation in water δ2H values are recorded by beeswax δ2H values. This survey demonstrates the promise of stable isotopes for region-of-origin assignment, using honeycomb wax δ2H values, which complements carbon isotope analysis to detect adulteration.