Improved Method to Identify and Quantify Antibiotics in Chicken Meat

In Europe, the European Commission maintains specific guidelines to regulate drug residues found in products of animal origin and ensure they are maintained at safe levels. For these guidelines to be effective, sensitive screening methods are needed to detect drugs residues in various samples, including meat products. Liquid chromatography–tandem mass spectrometry (LC-MS/MS) has the ability to target a wide range of drug classes and has been used previously to screen different antibiotics in muscle and kidney samples.¹Scientists have now developed an improved strategy to identify and quantify veterinary drugs in meats using LC-MS/MS.²This newly developed method has the ability to identify and quantify up to 36 different antibiotics from seven different chemical classes including aminoglycosides, macrolides, lincosamides, sulfonamides, tetracyclines, quinolones and trimethoprim. Key to the success of this protocol was the advanced instrumentation employed by the scientists. Sample cleanup and chromatographic separation was completed using a turbulent ﬂow chromatography Transcend TLX-1 system using Turbo Flow columns (all from Thermo Scientific). Its automated platform eliminated the need for manual sample handling, thus being advantageous in both efficiency and cost effectiveness. The turbulent flow chromatography system was coupled to a TSQ Quantum Access Max triple quadruple mass spectrometer (Thermo Scientific). Data was acquired using the selected reaction monitoring mode (SRM), with the SRM transitions finely tuned to each target analyte. Quantifier and qualifier transition ions confirmed the specificity of this protocol, and the precision was determined using spiked samples in replicate, as compared in different runs on different days. All in all, the accuracy was determined to be within acceptable ranges. To demonstrate the validity of this approach, the scientists examined the 20 samples of chicken meat and meat products purchased from a local market for traces of antibiotics. Just one out of the 36 antibiotics was present and in only one of the samples analyzed. The drug, enroﬂoxacin, was found in chicken ham, and was far below the acceptable limit for veterinary drugs present in meats. After validating this protocol in-house according to the criteria speciﬁed for quantitative methods described in the European Commission Decision 2002/675/EC³, the researchers recommended this protocol to be used to enforce the limits described for veterinary drugs in consumable meats. References