Determination of some Tetracycline antibiotics and their epimers residues in meat and meat products by liquid chromatography-tandem mass spectrometry (LC-MS/MS)

The study was conducted with the aim of developing and validating a method for determining the content of some tetracycline group substances including tetracycline (TC), oxytetracycline (OTC), chlortetracycline (CTC), metacycline (MC), doxycycline (DC) and epimers: 4-epi oxytetracycline (4-epi OTC), 4-epi tetracycline (4-epi TC), 4-epi chlortetracycline (4-epi CTC) in meat and meat products by liquid chromatography tandem mass spectrometry (LC-MS/MS). The sample processing procedure was quick and simple: the sample was extracted with McIlvaine-EDTA buffer, and the protein was precipitated with trichloroacetic acid. Then, the extract was cleaned on a HLB solid-phase extraction column. The separation was performed on a reversed-phase X-bridge C18 column (150 mm x 2.1 mm id; 3.5 μm), mobile phase channel A was 0.1% formic acid in H2O, channel B was ACN; flow rate 0.5 mL/min, injection volume 10 μL. The validated method showed good specificity, the standard curve of the analytes was linear in the concentration range of 15 – 150 μg/kg. The limit of detection (LOD) and limit of quantification (LOQ) were achieved with the corresponding analytes of 5 μg/kg and 15 μg/kg. The accuracy was assessed by recovery in the range of 84.23 – 108.5%, the precision was assessed by repeatability and internal reproducibility met the requirements according to AOAC. The method was applied to analyze the content of tetracycline antibiotics and epimers in 10 food samples (chicken, pork, ham, sausage) collected from the market.