Direct-injection high performance liquid chromatography ion trap mass spectrometry for the quantitative determination of olanzapine, clozapine and N-desmethylclozapine in human plasma.
A specific and sensitive direct-injection high performance liquid chromatography electrospray ionization tandem mass spectrometry (HPLC/ESI-MS/MS) method has been developed for the rapid identification and quantitative determination of olanzapine, clozapine, and N-desmethylclozapine in human plasma. After the addition of the internal standard dibenzepin and dilution with 0.1% formic acid, plasma samples were injected into the LC/MS/MS system. Proteins and other large biomolecules were removed during an online sample cleanup using an extraction column (1 x 50 mm i.d., 30 microm) with a 100% aqueous mobile phase at a flow rate of 4 mL/min. The extraction column was subsequently brought inline with the analytical column by automatic valve switching. Analytes were separated on a 5 microm Symmetry C18 (Waters) analytical column (3.0 x 150 mm) with a mobile phase of acetonitrile/0.1% formic acid (20:80, v/v) at a flow rate of 0.5 mL/min. The total analysis time was 6 min per sample. The inter- and intra-assay coefficients of variation for all compounds were <11%. By eliminating the need for extensive sample preparation, the proposed method offers very large savings in total analysis time.
Institute of Forensic Medicine, Karl-Franzens University Graz, Universitaetsplatz 4/II, A8010 Graz, Austria. manfred.kollroser@uni-graz.at
Manfred
M
Kollroser
Caroline
C
Schober
D014150:Antipsychotic Agents / Q000097:blood*; D001569:Benzodiazepines; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D003024:Clozapine / Q000031:analogs & derivatives* / Q000097:blood*; D006801:Humans; D000077152:Olanzapine; D010890:Pirenzepine / Q000031:analogs & derivatives / Q000097:blood*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
D014150:Antipsychotic Agents; D001569:Benzodiazepines; C058272:norclozapine; D010890:Pirenzepine; D003024:Clozapine; D000077152:Olanzapine