Extraction and preconcentration of β-blockers in human urine for analysis with high performance liquid chromatography by means of carrier-mediated liquid phase microextraction

A novel method was developed for the analysis of four β-blockers, namely sotalol, carteolol, bisoprolol, and propranolol, in human urine by coupling carrier-mediated liquid phase microextraction (CM-LPME) to high performance liquid chromatography (HPLC). By adding an appropriate carrier in organic phase, simultaneous extraction and enrichment of hydrophilic (sotalol, carteolol, and bisoprolol) and hydrophobic (propranolol) drugs were achieved. High enrichment factors were obtained by optimizing the compositions of the organic phase, the acceptor solution, the donor solution, the stirring rate, and the extraction time. The linear ranges were from 0.05 to 10.0 mg L−1 for sotalol and carteolol, and from 0.05 to 8.0 mg L−1 for bisoprolol and propranolol. The limits of detection (S/N = 3) were 0.01 mg L−1 for sotalol, carteolol, and bisoprolol, and 0.005 mg L−1 for propranolol. The relative standard deviations were lower than 6%. The developed method exhibited high analyte preconcentration and excellent sample clean-up effects with little solvent consumption and was found to be sensitive and suitable for simultaneous determination of the above four drugs spiked in human urine. Furthermore, the successful analysis of propranolol in real urine specimens revealed that the determination of β-blockers in human urine is feasible using the present method.