Quick screening of priority beta-agonists in urine using automated TurboFlow (TM)-LC/Exactive mass spectrometry

This paper describes a method for the determination of priority beta-agonists in urine based on a fully automated sample preparation procedure using an online TurboFlow (TM) chromatography clean-up step and determination with Orbitrap (TM) mass analyser technology. The principle of the method was the enrichment of the beta-agonists after enzymatic hydrolysis overnight on a small column packed with a special stationary phase (TurboFlow (TM)) while flushing away sample matrix and interfering compounds. Thereafter, the analytes were transferred onto an analytical column and detected by liquid chromatography/high-resolution mass spectrometry in full-scan mode at a resolution of R = 50,000 FWHM (full width at half maximum) and in higher energy collisional dissociation (HCD) scan mode at a resolving power of 10,000 FWHM. The optimisation of each step of the method, such as selection of the TurboFlow (TM) and analytical column as well as sample loading and elution parameters were performed using a standard solution containing salbutamol, clenbuterol and mabuterol at a concentration of 100 mu g l(-1). The developed automated sample preparation significantly improved the throughput and efficiency of the previously used screening method and it resulted in a considerable reduction in analysis time. Validation experiments including 24 beta-agonists in urine gave decision limits (CC alpha) between 0.05 and 0.35 mu g l(-1). The repeatability of analyses for urine samples spiked at 0.5 mu g l(-1) was within the range of 5-26% and recoveries for all compounds were within 89-107%.