Ultrasensitive determination of NE-100, a novel sigma ligand, in human plasma by liquid chromatography and electrospray ionization tandem mass spectrometry combined with a column-switching technique.

For the highly sensitive and selective determination of NE-100, a novel sigma ligand, at levels of low picogram per milliliter of human plasma, a method with excellent reliability employing liquid chromatography (LC)-electrospray ionization (ESI) tandem mass spectrometry (MS-MS) combined with a column-switching technique has been developed. The method involves the use of a stable isotope labeled compound as the internal standard (I.S.

Simultaneous high-performance liquid chromatographic determination of lornoxicam and its 5'-hydroxy metabolite in human plasma using electrochemical detection.

A selective and sensitive high-performance liquid chromatographic method with coulometric detection is described for the simultaneous quantitation of lornoxicam, a new oxicam class drug, and its 5'-hydroxy metabolite in human plasma. The two analytes and the internal standard are extracted from plasma at pH 4.0 by liquid-liquid extraction and separated on a C18 column.

Selected ion monitoring for the determination of bromovalerylurea in human plasma.

A gas chromatography-selected ion monitoring procedure with chemical ionization is described for the determination of bromovalerylurea (BVU) in human plasma. BVU was extracted with ether after addition of 2-bromo-2-methylpropylurea as an internal standard. The lower limit of BVU quantification by this method was 2 ng/0.

Determination of gallopamil in human plasma by selected ion monitoring.

A gas chromatographic mass spectrometric procedure using selected ion monitoring is described for the quantification of gallopamil in human plasma. Gas chromatographic separation of gallopamil from phenolic metabolite isomers is made possible by treatment with ethyl chloroformate. The detection limit for the quantitation by the present method is 0.