Pre-concentration and Sensitive Determination of Propranolol and Metoprolol Using Dispersive Solid-Phase Microextraction and High-Performance Liquid Chromatography in Biological, Wastewater, and Pharmaceutical Samples

Determination of drugs at environmental and biological samples is a critical issue for controlling the effects of a drug on human health and environmental pollution. In the present study, a dispersive solid phase microextraction mode was developed for the preconcentration and cleanup of low amounts of propranolol and metoprolol before their determination with a high-performance liquid chromatography diode array detector. Carboxyl functionalized single-walled carbon nanotubes supported by magnetic nanoparticles (Fe3O4@SWCNT-COOH) were synthesized as a sorbent using a chemical procedure. Various factors affecting the microextraction method such as pH, donor phase volume, extraction desorption time, sorbent quantity solvent type and volume, and stirring rate were evaluated along with improving efficiency. The dynamic linear range of the method for the propranolol and metoprolol determination was 0.1-234 and 0.2-187 mg L-1 with a determination correlation coefficient (R2) of 0.9989 and 0.9984, respectively. Besides, the enrichment factor for the determination of propranolol and metoprolol were 283.1 and 278.7, respectively. Limit of detection (LOD) and limit of quantification (LOQ) were turn down by 0.06 and 0.2 for the analyte determination, correspondingly. Intraday and inter-day RSD% were determined for five times to determine propranolol and metoprolol at a concentration of 2.0 ng.mL-1 and were lower than 3.26 and 4.29%, respectively. Determination of propranolol and metoprolol in hospital wastewater, human urine and plasma samples indicated that this proposed method can be employed to analyze the actual samples without the significant matrix effects with a recovery range of 91.0-97.2% and an RSD of less than 5.49%.