Measurement of apixaban, dabigatran, edoxaban and rivaroxaban in human plasma using automated online solid-phase extraction combined with ultra-performance liquid chromatography-tandem mass spectrometry and its comparison with coagulation assays

Background: Measurement of direct oral anticoagulants (DOACs) concentration in patient blood is essential in special clinical circumstances. Methods: We developed a fast, selective and sensitive method for simultaneous measurement of DOACs in human plasma consisting of an automated online solid-phase extraction method coupled with ultra-performance liquid chromatography electrospray ionization-tandem mass spectrometry (online SPE-UPLC-MS/MS). Results: The calibration curves of all DOACs were linear over the working range (apixaban: 0.25-760 g/L, r > 0.99; dabigatran: 0.5-900 g/L, r > 0.99; edoxaban: 0.6-800 g/L, r > 0.99; rivaroxaban: 0.5-900 g/L, r > 0.99). Limits of detection in the plasma matrix were < 0.2 g/L, whereas the lower limits of quantification were < 0.6 g/L for all DOACs. The intraassay and interassay CV for all DOACs were < 6%. Mean recoveries were between 61.4% and 91.6%. Method comparison between our online SPE-UPLC-MS/MS assay and commercially available functional based coagulation assays using patient samples showed a high degree of correlation for all investigated DOACs. Conclusions: We developed and validated the first online SPE-UPLC-MS/MS method for fast, sensitive, specific, and reliable measurement of the new generation of DOACs and compared this method with commercial available coagulation assays.