Analysis of Multiple β-Agonist and β-Blocker Residues in Porcine Muscle Using Improved QuEChERS Method and UHPLC-LTQ Orbitrap Mass Spectrometry

The objective of the present study is to develop and optimize a simple, high-throughput method for determining 14 beta-agonists (i.e., banbuterol, brombuterol, cimaterol, cimbuterol, clenbuterol, clenpeterol, clorpenaline, isoxsuprine, mabuterol, mapenterol, ractopamine, salbutamol, terbutaline, and tulobuterol) and two beta-blockers (propranolol and penbutolol) in porcine muscle. The samples were pretreated by a modified quick, easy, cheap, efficient, rugged, and safe (QuEChERS) method, and analysis was carried out in a reversed phase HSS T3 C18 column using gradients of acetonitrile and 5 mmol L-1 ammonium acetate (0.1 % formic acid) solution for elution. Ultra-high performance liquid chromatography coupled with high-resolution mass spectrometry (UHPLC-LTQ Orbitrap MS, resolution 60,000) was used for qualification and quantification of the 16 target compounds. Under optimized conditions, the limits of detection and quantification obtained ranged from 0.17 to 1.67 mu g kg(-1) and from 0.56 to 5.00 mu g kg(-1), respectively. Recoveries for spiking levels of 5.0, 10.0, and 20.0 mu g kg(-1) ranged from 62.4 to 121.9 %, from 60.4 to 104.3 %, and from 66.5 to 121.3 %, respectively. The relative standard deviations obtained were lower than 20 % for all spiking levels assayed. The proposed method was applied successfully in sample analysis, and satisfactory results were obtained.