Simultaneous Determination of Cyclophosphamide and Carboxyethylphosphoramide Mustard in Human Plasma Using Online Extraction and Electrospray Tandem Mass Spectrometry (HTLC-ESI-MS/MS).

BAI F; FRAGA C; TAGEN M; SCHAIQUEVICH P; STEWART CF

JOURNAL OF CHROMATOGRAPHY B

ELSEVIER

Año: 2009 vol. 15 p. 1709 - 1715

0378-4347

A rapid and selective method for simultaneous determination of cyclophosphamide and its metabolite carboxyethylphosphoramidemustard (CEPM) was developed using online sample preparation and separation with tandemmass spectrometric detection.Diluted plasmawas injected onto an extraction column (Cyclone MAX 0.5mm×50mm, >30m), the sample matrix was washed with an aqueous solution, and retained analytes were transferred to an analytical column (Gemini 3mC18110A,100mm×2.0mm) using a gradient mobile phase prior to detection by MS/MS. Analytes were detected in an API-3000 LC- MS/MS systemusing positivemultiple-reactionmonitoringmode (m/z 261/140 and 293/221 for CTX andCEPM, respectively). Online extraction recoveries were 76% and 72% for cyclophosphamide and CEPM. Within-day and between-day variabilitieswere <3.0%, and accuracieswere between −6.9% and 5.2%. This method has been used to measure plasma cyclophosphamide and CEPM concentrations in an ongoing Phase II study in children with newly diagnosed medulloblastoma.