Analysis and occurrence of 14 sulfonamide antibacterials and chloramphenicol in honey by solid-phase extraction followed by LC/MS/MS analysis.

A method was developed for the analysis of 14 sulfonamide antibiotics and chloramphenicol in honey. These antibiotics have been banned for use in food-producing animals; yet, their residues were found in many samples, illustrating the need for a multiresidue analysis for these antibiotics in honey. The method described here uses an acid hydrolysis step to liberate the sugar-bound sulfonamides followed by a solid-phase extraction to remove potential interferences. Analysis was by liquid chromatography--electrospray ionization--tandem mass spectrometry in negative mode for all 15 analytes. This MRM method generated two structurally significant transitions per compound, and it was designed to conform to U.S. Food and Drug Administration MS confirmation guidelines. It also provides 4-EU identification points. One hundred sixteen samples from 25 countries were analyzed, and 38% were found to contain at least one target antimicrobial. Five different target compounds were found in honey from 13 different countries.