Metabolomic analysis of swine urine treated with β2-agonists by ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry

The illegal use of beta(2)-agonists in livestock production was previously detected by efficient methods based on mass spectrometry to control the residues of these drugs. Nevertheless, such methods still remain a challenging task for authorities who monitor these residues because the use of cocktails composed of mixtures of low amounts of several substances as well as the synthesis of new compounds of unknown structure prevent efficient prevention of illegal use of growth-promoting agents. Here, we outlined a metabolomics-based strategy for detecting the use of cocktails composed of mixtures of low amounts of three beta(2)-agonists via urine profiling. Urine profiles of controls and swine treated with mixture of low amounts of three substances (clenbuterol, salbutamol, and ractopamine) were analyzed with ultra-high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry. The metabolic differences between controls and beta(2)-agonists-treated groups were compared using multivariate data analysis. Fourteen metabolites were identified related with the beta(2)-agonists treatment, while two co-biomarkers, 2-indolecarboxylic acid and fluorometholone acetate, either in single or cocktails of low-dose mixture of clenbuterol, salbutamol, and ractopamine, could be considered as diagnostic markers for the detection of illegal use of beta(2)-agonists. The results of depletion study demonstrated that it is practical to use the markers for monitoring of beta(2)-agonists. (C) 2015 Elsevier B.V. All rights reserved.