Abstract
A hydroxylated poly(glycidyl methacrylate‐co‐ethylene dimethacrylate) (GMA‐co‐EDMA) monolithic capillary was prepared for polymer monolith microextraction (PMME). Coupled to HPLC with UV detection, this extraction medium was successfully applied to establish a simple and fast method for the analysis of clenbuterol (CLB) in urine. To obtain optimum extraction performance, the effects of pH value and ionic strength of the sample matrix on extraction efficiency were investigated. The linearity of the method was evaluated over a concentration range of 10–2000 ng/mL and the correlation coefficient (R^2^ value) was 0.9985. The detection limit and quantification limit were 2.3 and 7.7 ng/mL, respectively. Good reproducibility of the method was obtained, yielding the intra‐ and interday RSDs less than 5.1 and 9.1%, respectively. Moreover, the hydroxylated poly(GMA‐co‐EDMA) monolithic capillary exhibited good preparation reproducibility and long‐term extraction life. When applied to the determination of CLB in urine samples, an effective removal of interfering compounds was achieved and recoveries were in the range of 87.6–106%. The determination of CLB from one real sample including pretreatment, extraction, and analysis could be finished within 30 min.