title: Quantitative determination of clonazepam in plasma by gas chromatography-negative ion chemical ionization mass spectrometry.
abstract: A gas chromatographic-negative ion chemical ionization mass spectrometric (GC-NCI-MS) method for the quantitative analysis of clonazepam in human plasma is described. Clonazepam (M(r) = 315) was derivatized by N,O-bis-(trimethylsilyl)trifluoroacetamide with 1% trimethylchlorosilane. A pre-conditioning procedure involving injection of a silyl-8 and ethyl acetate extraction solution from plasma reduces the interaction between clonazepam-TMS and the analytical system. The routine limit of quantification was set to be 0.25 ng/ml with an injection volume of 2 microliters and a sample volume of 1 ml. The signal-to-noise ratio was greater than five. The detection limit for clonazepam can reach 0.1 ng/ml. The isotope clonazepam-d5 was used as the internal standard.
authors.affiliation: Clinical Research Associates, New York, NY 10010, USA.
authors.forename: D
authors.initials: D
authors.lastname: Song
authors.forename: S
authors.initials: S
authors.lastname: Zhang
authors.forename: K
authors.initials: K
authors.lastname: Kohlhof
mesh_terms: D000927:Anticonvulsants / Q000097:blood*; D002998:Clonazepam / Q000097:blood*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006801:Humans; D012680:Sensitivity and Specificity
chemical_list: D000927:Anticonvulsants; D002998:Clonazepam