A sensitive and rapid UFLC-APCI-MS/MS bioanalytical method for quantification of endogenous and exogenous Vitamin K1 isomers in human plasma: Development, validation and first application to a pharmacokinetic study.

Due to lack of suitable bioanalytical methods in previous literature, for simultaneous estimation of Vitamin K1 isomers, in compliance with the current regulatory expectation, we aimed to develop a sensitive and rapid method with UFLC-APCI-MS/MS (ultrafast liquid chromatography - tandem mass spectrometry) using human plasma. A simple and cost effective procedure was implemented with the combination of protein precipitation and liquid extraction, to isolate the targets from plasma sample, while achieving an insignificant matrix effects and high recovery (≥88.2%).

Sensitive LC-MS/MS-ESI method for simultaneous determination of montelukast and fexofenadine in human plasma: application to a bioequivalence study.

A rapid, simple, sensitive and selective LC-MS/MS method was developed and validated for simultaneous quantification of montelukast (MT) and fexofenadine (FF) in human plasma (200 μL) using montelukast-d6 (MT-d6 ) and fexofenadine-d10 (FF-d10 ), respectively as an internal standard (IS) as per the US Food and Drug Administration guidelines. The chromatographic resolution was achieved on a Chromolith RP18e column using an isocratic mobile phase consisting of 20 mm ammonium formate-acetonitrile (20:80, v/v) at flow rate of 1.2 mL/min.