Stability of dicyclohexylamine and fumagillin in honey

Fumagillin is extensively used to control nosema disease in apiculture. In the commercial formulation, fumagillin is present as a salt in an equimolar quantity with dicyclohexylamine (DCH). In this study DCH was observed to be significantly more resistant to degradation in honey than fumagillin using LC-MS/MS analysis. Observed half-lives for DCH ranged from a minimum of 368 days when kept at 34 °C in darkness, to a maximum of 852 days when stored at 21 °C in darkness. A maximum half-life of 246 days was observed for fumagillin in samples kept in darkness at a temperature of 21 °C. The observed half-life of fumagillin was estimated to be 3 days when exposed to light at 21 °C, and complete decomposition was observed after 30 days under the same conditions. The stability of DCH, combined with its genotoxicity and tumorigenic properties make it an important potential contaminant in honey destined for human consumption.