The application of phospholipid removal columns and ultra-high performance liquid chromatography-tandem quadrupole mass spectrometry for quantification of multi-class antibiotics in aquaculture samples

In this study a robust and sensitive method based on a proposed sample purification procedure, using zirconia-coated Phree (TM) columns and analysis by ultra-high performance liquid chromatography with triple quadrupole tandem mass spectrometry are presented for the assessment of multi-class antibiotics in farmed fish species. The sample preparation procedure benefited from combined precipitation of proteins and selective removal of phospholipids by Phree (TM) columns, resulting in a high sensitivity of the method (LOQ 0.3-9 mg kg(-1)). The in-house validation results (precision, repeatability, decision limit CC alpha, detection capability CC beta, etc.) indicate that the elaborated method is fully suitable for the analysis of the main classes of antibiotics in accordance with the European Union (EU) Commission Decision 2002/657/EC. The method was applied to the analysis of antibiotics in trout and sturgeon samples obtained from the local inland aquacultures in Latvia. The results revealed the presence of two antibiotics (enrofloxacin and trimethoprim) in 12 out of the 20 analysed fish samples at concentrations (0.33-12.2 mu g kg(-1)) below the MRLs, thus causing no acute risks to consumers. (C) 2016 Elsevier B.V. All rights reserved.