title: Trapping 4-fluorobenzyl chloride in human plasma with chemical derivatization followed by quantitative bioanalysis using high-performance liquid chromatography/tandem mass spectrometry.
abstract: A quantitative bioanalytical method involving chemical derivatization, solid phase extraction (SPE) and high-performance liquid chromatography/tandem mass spectrometry (HPLC/MS/MS) was developed for the determination of 4-fluorobenzyl chloride (4FBCl) in human plasma. 4FBCl is a volatile and reactive molecule that is very unstable in human plasma. In order to stabilize 4FBCl in plasma samples prior to storage, 4-dimethylaminopyridine (DMAP) was added, forming a stable quaternary amine salt derivative. A three-step weak cation-exchange SPE procedure was then employed to remove excess DMAP. The plasma extracts were analyzed by HPLC/MS/MS using a TurboIonspray interface and multiple reaction monitoring. Unlike 4FBCl, the quaternary amine derivative shows excellent sensitivity in electrospray mass spectrometry. The method was validated over a concentration range of 0.5-500 ng/mL using 45 microL of plasma. The maximum within-run and between-run precision observed in a three-run validation for quality control (QC) samples was 12.5 and 7.6%, respectively. The maximum percentage bias observed at all QC sample concentrations was 11.9%. The method has proven to be robust and compatible with high-throughput bioanalysis.
authors.affiliation: Worldwide Bioanalysis, Drug Metabolism and Pharmacokinetics, GlaxoSmithKline Pharm, 709 Swedeland Rd., King of Prussia, PA 19406, USA. eric.y.yang@gsk.com
authors.forename: Eric
authors.initials: E
authors.lastname: Yang
authors.forename: Sherry
authors.initials: S
authors.lastname: Wang
authors.forename: Chester
authors.initials: C
authors.lastname: Bowen
authors.forename: John
authors.initials: J
authors.lastname: Kratz
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Cyronak
authors.forename: Jacob R
authors.initials: JR
authors.lastname: Dunbar
mesh_terms: D001593:Benzyl Compounds / Q000097:blood* / Q000737:chemistry*; D001774:Blood Chemical Analysis / Q000379:methods*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D008832:Microchemistry / Q000379:methods*; D011725:Pyridines / Q000737:chemistry*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
chemical_list: C417980:4-(dimethylamine)pyridine; C500373:4-fluorobenzyl chloride; D001593:Benzyl Compounds; D011725:Pyridines