Determination of 5-HT3 Receptor Antagonists in Human Urine by Porous Graphitic Carbon (PGC) Solid Phase Extraction (SPE) Coupled with High Performance Liquid Chromatography-Tandem Mass Spectrometry (HPLC-MS/MS)

Abstract

The quantitative determination of drugs in urine by high performance liquid chromatography electrospray-ionization mass spectrometry (HPLC-ESI-MS) is challenging due to complex matrix interferences and the relatively low concentrations of analytes in urine. In this study, porous graphitic carbon (PGC) was investigated as solid phase extraction (SPE) sorbent before HPLC-ESI-MS determination of three 5-hydroxytryptamine (3) (5-HT3) receptor antagonists from human urine. The factors affecting extraction of the target antagonists were investigated and optimized systematically by using single-factor tests. The optimized SPE procedure was developed for the simultaneous extraction and sample pretreatment of tropisetron, ondansetron, and granisetron in urine by HPLC-ESI-MS/MS. Using the optimized conditions, the matrix effects were reduced by the PGC-based SPE clean-up procedure, with acceptable matrix effects for tropisetron, ondansetron, and granisetron from 96.53% to 98.42%, 93.19% to 94.36%, and 94.48% to 95.60%, respectively. The reported method significantly removes matrix interferences from the urine samples and exhibited satisfactory recovery and process efficiency for the determination of tropisetron, ondansetron, and granisetron. The established pretreatment method provides a promising strategy for the removal of interferences from hydrophilic basic drugs in biological fluids.