Simple and rapid analysis of muscarine in human urine using dispersive micro-solid phase extraction and ultra-high performance liquid chromatography-high resolution mass spectrometry†
This paper presents a simple analytical method for the rapid determination of muscarine residue in human urine based on a novel dispersive micro-solid phase extraction (DMSPE) and ultra-high performance liquid chromatography-high resolution mass spectrometry (UHPLC-HRMS). A weak cation exchange sorbent material (COOH) as a sorbent for the DMSPE method was employed to extract muscarine from human urine. Several important parameters affecting the extraction efficiency in the DMSPE method using the COOH sorbent, such as the sample pH, the amount of COOH sorbent, the adsorption time, and the type and volume of desorption solvent, were carefully investigated and optimized by the univariate method and design of experiments. Under the optimum extraction conditions, the method showed a good linearity (r > 0.999) in the range of 0.4–40 μg L−1 for the analyte. The LOD and LOQ values of muscarine were 0.1 μg L−1 and 0.4 μg L−1 respectively. The extraction recoveries of muscarine from the urine samples spiked at four different concentrations (0.4, 0.8, 4 and 40 μg L−1) were in a range of 74.4% to 91.5%. The intra- and inter-day precisions varied from 2.1% to 8.2% and from 1.7% to 7.3%, respectively. The accuracy ranged from −2.1% to −6.9%. The results showed that the proposed method was simple, rapid, economical and effective for the determination of muscarine in human urine.