Simple high-performance liquid chromatographic column-switching technique for the on-line immunoaffinity extraction and analysis of flunitrazepam and its main metabolites in urine.
A sensitive, simple and rapid method without sample pretreatment is presented for the simultaneous determination of flunitrazepam and its main metabolites (norflunitrazepam, 7-amino- and 7-acetamidoflunitrazepam) in urine. The single-step procedure is based on a column-switching technique which uses an immobilized antibody in an extraction column following concentration on a precolumn and separation on an analytical column. UV detection was performed at 254 nm. The reusability of the antibody exceeds 88 runs and a complete analysis was performed in less than 40 min. The method shows coefficients of variation below 9.9% and rates of recovery greater than 92% tested at the level of 50 ng/ml urine. The limit of detection was below 2 ng/ml urine for the four compounds.
Deinl
I
I
Institute of Forensic Medicine, Erlangen, Germany.
Angermaier
L
L
Franzelius
C
C
Machbert
G
G
D014151:Anti-Anxiety Agents; D002498:Centrifugation; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D005445:Flunitrazepam / Q000031:analogs & derivatives / Q000378:metabolism* / Q000652:urine*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007163:Immunosorbent Techniques; D007700:Kinetics; D012680:Sensitivity and Specificity
D014151:Anti-Anxiety Agents; D005445:Flunitrazepam; C036343:7-aminoflunitrazepam