Development of a Method Based on DLLME and UFLC-DAD for the Determination of Antibiotics in Honey Samples and the Study of Their Degradation Kinetics

In this work, a method was developed, based on dispersive liquid-liquid microextraction (DLLME) and analysis by ultra-fast liquid chromatography coupled to diode array detector (UFLC-DAD), to simultaneously determine ten antibiotics of two different classes in honey, as well as to evaluate their degradation kinetics in this matrix. The extraction was optimized by a Box-Behnken design and the method provided good linearity and precision, limits of detection (LODs) in the range of 3.1-6.8 mu g kg(-1) and recoveries between 82.9 and 105.7%. The decay velocities along the storage period have followed a first order model for nine antibiotics. while one has fitted a zero order model. In the analysis of 33 samples, sulfadimethoxine and tetracycline were found in four samples of the same year and type of blooming, freshly produced in different places, at concentrations, respectively, below and 79% higher than the established by the Brazilian legislation. This suggests an application of those drugs to the beehives, probably shortly before the samples were taken.