Simultaneous and confirmative detection of multi-residues of β2-agonists and β-blockers in urine using LC-MS/MS/MS coupled with β-receptor molecular imprinted polymer SPE clean-up

A liquid chromatography-linear ion-trap spectrometry (LC-MS3) method using -receptor molecular-imprinted polymer (MIP) solid-phase extraction (SPE) as clean-up was developed to determine simultaneously and confirmatively residues of 25 (2)-agonists and 21 -blockers in urine samples. Urine samples were subjected to enzymatic hydrolysis by -glucoronidase/arylsulphatase, and then extracted with perchloric acid. Sample clean-up was performed using -receptor MIP SPE. A Supelco Ascentis((R)) express Rp-Amide column was used to separate the analytes, and MS3 detection used an electrospray ionisation source in positive-ion mode. Recovery studies were carried out using blank urine samples fortified with the 46 analytes at the levels of 0.5, 1.0 and 2.0gl(-1). Recoveries were obtained ranging from 60.1% to 109.9% with relative standard deviations (RSDs, n=7) from 0.5% to 19.4%. The limits of detection (LODs) and limits of quantitation (LOQs) of the 46 analytes in urine were 0.02-0.18 and 0.05-0.60gl(-1), respectively. As a result of the selective clean-up by MIP SPE and MS3 detection of the target drugs, the sensitivity and accuracy of the present method was high enough for monitoring (2)-agonist and -blocker residues in urine samples. Satisfactory results were obtained in the process of the determination of positive urine samples.