title: Determination of flunitrazepam and 7-aminoflunitrazepam in human urine by on-line solid phase extraction liquid chromatography-electrospray-tandem mass spectrometry.
abstract: A method using an on-line solid phase extraction (SPE) and liquid chromatography with electrospray-tandem mass spectrometry (LC-ES-MS/MS) for the determination of flunitrazepam (FM2) and 7-aminoflunitrazepam (7-aminoFM2) in urine was developed. A mixed mode Oasis HLB SPE cartridge column was utilized for on-line extraction. A reversed phase C(18) LC column was employed for LC separation and MS/MS was used for detection. Sample extraction, clean-up and elution were performed automatically and controlled by a six-port valve. Recoveries ranging from 94.8 to 101.3% were measured. For both 7-aminoFM2 and FM2, dual linear ranges were determined from 20 to 200 and 200-2000ng/ml, respectively. The detection limit for each analyte based on a signal-to-noise ratio of 3 ranged from 1 to 3ng/ml. The intra-day and inter-day precision showed coefficients of variance (CV) ranging from 4.6 to 8.5 and 2.6-9.2%, respectively. The applicability of this newly developed method was examined by analyzing several urine samples.
authors.affiliation: Department of Chemistry, Soochow University, P.O. Box 86-72, Taipei, Taiwan.
authors.forename: Ming-Ren
authors.initials: MR
authors.lastname: Fuh
authors.forename: Shi-Wei
authors.initials: SW
authors.lastname: Lin
authors.forename: Li-Lung
authors.initials: LL
authors.lastname: Chen
authors.forename: Tzuen-Yeuan
authors.initials: TY
authors.lastname: Lin