Rapid determination of rivaroxaban in human urine and serum using colloidal palladium surface‐assisted laser desorption/ionization mass spectrometry

Rationale Rivaroxaban is a new anticoagulant drug that has recently been introduced for clinical applications. To ensure optimum efficacy while minimizing the risk of toxicity and other adverse effects, a simple and sensitive analytical procedure for monitoring the concentration of rivaroxaban in biological fluids is required. Methods Rivaroxaban was extracted from aqueous solutions by dispersive liquid-liquid microextraction (DLLME). Detection of rivaroxaban was achieved through surface-assisted laser desorption/ionization mass spectrometry (SALDI-MS) using colloidal palladium as the SALDI matrix. Results The calibration curve for rivaroxaban in aqueous solutions was linear over the concentration range from 5 to 500 nM. The limit of detection (LOD) for rivaroxaban at a signal-to-noise ratio of 3 was 2 nM. With a sample-to-extract volume ratio of 200, the enrichment factors were calculated to be 141. This method was successfully applied for the determination of rivaroxaban in human urine and serum samples. The LODs for rivaroxaban in urine and serum were calculated to be 6 nM and 60 nM, respectively. Conclusions The analysis speed, together with the ease of operation and high sensitivity, allows SALDI-MS method to be particularly suitable for the high-throughput screening of rivaroxaban levels in human urine and serum samples. Copyright © 2015 John Wiley & Sons, Ltd.