Journal of Chromatography B, 976–977 (2015) 49–54 Contents lists available at ScienceDirect Journal of Chromatography B jou rn al hom ep age: www.elsevier.com/locate/chromb Multidetection of antibiotics in liver tissue by ultra-high-pressure-liquid-chromatography–tandem mass spectrometry Andreia Freitas a,b , Jorge Barbosa a,b , Fernando Ramos b,c,∗ a INIAV-LNIV, Laboratório Nacional de Investigac ¸ ão Veterinária, Rua General Morais Sarmento, 1500-311 Lisboa, Portugal b CEF-Center for Pharmaceutical Studies, Health Sciences Campus, Pharmacy Faculty, University of Coimbra, Azinhaga de Santa Comba, 3000-548 Coimbra, Portugal c CNC-Centre for Neuroscience and Cell Biology, Health Sciences Campus, Pharmacy Faculty, University of Coimbra, Azinhaga de Santa Comba, 3000-548 Coimbra, Portugal a r t i c l e i n f o Article history: Received 11 August 2014 Accepted 11 November 2014 Available online 20 November 2014 Keywords: Antibiotics Multiclass Multidetection UHPLC–MS/MS Liver Validation a b s t r a c t A multiresidue quantitative screening method covering 39 antibiotics from 7 different families by ultra-high-pressure-liquid-chromatography–tandem mass spectrometry (UHPLC–MS/MS) is described. Sulfonamides, trimethoprim, tetracyclines, macrolides, quinolones, penicillins and chloramphenicol are simultaneously detected in liver tissue. A simple sample treatment method consisting of extraction with a mixture of acetonitrile and ethylenediaminetetraacetic acid (EDTA) followed by solid-phase extraction (SPE) with a hydrophilic–lipophilic balanced (HLB) cartridge was developed. The methodology was validated, in accordance with Decision 2002/657/EC, by evaluating the follow- ing required parameters: decision limit (CC), detection capability (CC), specificity, repeatability and reproducibility. The precision, in terms of the relative standard deviation, was under 22% for all of the compounds, and the recoveries were between 80% and 110%. The CC and CC were determined accord- ing to the maximum residue limit (MRL) or the minimum required performance limit (MRPL), when established. © 2014 Elsevier B.V. All rights reserved. 1. Introduction Antibiotics are widely used for therapeutic and prophylactic purposes in food-producing animals and to promote animal growth [1]. The use of antibiotics as growth promoters is considered fraud- ulent in Europe because it can lead to residues of these compounds persisting in edible matrices. These antibiotic residues can result in allergic reactions in some hypersensitive individuals and in the appearance of bacterial strains that are resistant to drugs that are used in both veterinary and human medicines [2], which are cur- rently considered a huge worldwide concern. For that reason, the European Community determined the need for the mandatory control of the veterinary drugs in food from ani- mal origin designated for human consumption [3]. For permitted ∗ Corresponding author at: CNC-Centre for Neuroscience and Cell Biology, Health Sciences Campus, Pharmacy Faculty, University of Coimbra, Azinhaga de Santa Comba, 3000-548 Coimbra, Portugal. Tel.: +351 239 488492; fax: +351 239 488503. E-mail address: fjramos@ci.uc.pt (F. Ramos). veterinary drugs, the maximum residue limits (MRL) in foodstuff of animal origin were established and are listed in the EU Commission Regulation 37/2010 [4,5]. Food products containing concentrations of antibiotics exceeding the established MRL are inappropriate for human consumption. In the case of some non-authorized sub- stances, a minimum required performance limit (MRPL) has been set to harmonize the analytical performance of the methods used in different laboratories [6,7]. A wide variety of edible matrices must be monitored for the presence of veterinary residues, including muscle, liver, kidney, fat, milk, eggs, fish and honey. Nevertheless, there are relatively few multidetection and multiclass methods for the determina- tion of antibiotics in liver tissue. There are still very few methods describing approaches for analyzing different classes of com- pounds, particularly for their determination in liver tissue [8,9]. To our knowledge, the only available method for the determination of an extensive number of antibiotics from several classes in such a matrix was published by Kaufmann et al. [8], who detected 100 vet- erinary drugs in muscle, liver and kidney tissues using UPLC–ToF- MS. The main constraint with using ToF-MS methodologies is http://dx.doi.org/10.1016/j.jchromb.2014.11.008 1570-0232/© 2014 Elsevier B.V. All rights reserved.