Optimization and validation of the micellar electrokinetic capillary chromatographic method for simultaneous determination of sulfonamide and amphenicol-type drugs in poultry tissue

The report describes a new approach enabling simple and rapid multi-residue screening of seven sulfonamides (SAs): sulfamethazine (SMZ), sulfamerazine (SMR), sulfathiazole (STZ), sulfachloropyridazine (SCP), sulfamethoxazole (SMX), sulfacarbamide (SC), and sulfaguanidine (SG); and three amphenicol-type antibiotics: chloramphenicol (CAP), thiamphenicol (TAP), and florfenicol (FF) in animal tissue by micellar electrokinetic chromatography (MEKC). The analytes were isolated from tissue samples through solid-phase extraction (with a C18 cartridges) following protein precipitation with acetonitrile. The evaluated LOD and LOQ values ranged from 1.3 to 7.8 and from 4.5 to 26.1 ng/g, respectively. These values are far lower than the maximum residue limits (MRLs) set by several control authorities. Intra- and inter-day precision data were less than 9.5% and 11.2% for SAs, and 8.4% and 14.9% for amphenicols. Moreover, the method was found accurate, with the recoveries ranging from 86.4% to 109.4%. The absolute recoveries of the analysed drugs were higher than 77.2%. The results obtained in the validation process demonstrate that the developed CE method is suitable for simultaneous determination of SA and amphenicol residues in poultry tissue, with the total run time less than 8 min.