Introducing direct probe electrospray ionization tandem mass spectrometry in apiculture: Comparison with other mass spectrometric methods for the determination of antibiotics in bees and honey

Amphenicols and tetracyclines (TCs) antibiotics use in apiculture is mainly focused on the treatment of bee brood diseases. Despite their efficiency, the serious genotoxic effects that some elicit led to their banning for use in apiculture and for chloramphenicol (CAP) in all food-producing animals. In this work, three tandem mass spectrometric methods were developed and validated for the analysis and quantification of CAP, thiamphenicol (TF), florfenicol (FF), tetracycline (TC), oxytetracycline (OTC) and chlortetracycline (CTC) in honey and honeybees. With the first, we have demonstrated the first use of probe electrospray ionization (PESI) in conjunction with tandem mass spectrometry (MS/MS) for antibiotics determination in honey and bees entailing a minimum sample preparation for bees, resulting in rapid chemical analysis for both commodities. The second was a reversed-phase HPLC-ESI-MS/MS method sharing the same scope. With the third chiral HPLC-ESI-MS/MS method, it was attempted to separate CAP stereoisomers in both commodities since reports have shown that only the D-threo isomer displays antimicrobial properties. The analytical methods fulfilled validation criteria demonstrating recoveries in the range of 74–92%, managing to address the minimum required performance limit (MRPL) for CAP, with the exception of PESI-MS/MS. The latter displayed a detection capability (CCβ) for all compounds in proximity to 1 ng/g, and an overall runtime of 1.5 min. In total, 68 samples of honeybees and honey were evaluated for amphenicols and TCs residues. CAP was detected only in two honeybee samples, while one honey sample was positive to TC and OTC was detected in traces in another sample. PESI-MS/MS managed to quantify both TC in honey and CAP in bees in proximity to the values assigned by the conventional HPLC-ESI-MS/MS methods. With regard to the separation of CAP's isomers, the chiral method managed to resolute all isomers and quantify CAP in one bee sample in the form of its L-threo stereoisomer. Overall, ABCs detection in honey and related matrices still constitutes a challenge, considering their prevalence and potential applications in major honey-producing countries.