GLC/MS assay for loxapine in human biofluids and tissues with deuterium labeled analog as an internal standard.
A quantitative gas liquid chromatographic-mass spectrometric (GLC/MS) assay was developed for the determination of loxapine in human blofluids and tissues. The assay utilizes selected ion monitoring in a GLC effluent of the molecular ion of loxapine generated by electron-impact ionization (EI). Loxapine-d3 was used as the internal standard. The assay can measure 2 ng/mL of loxapine with about 6% precision. The curve relating the amounts of loxapine added in control plasma versus the ion intensity ratio (m/e 327/330) over a large range of loxapine concentrations was linear with essentially zero intercept. The method was used for the analysis of loxapine in human urine, plasma, brain, liver, lung and spleen.
D001923:Brain Chemistry; D003903:Deuterium; D003989:Dibenzoxazepines / Q000032:analysis*; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D007553:Isotope Labeling; D008099:Liver / Q000032:analysis; D008152:Loxapine / Q000032:analysis* / Q000097:blood / Q000652:urine; D008168:Lung / Q000032:analysis; D013154:Spleen / Q000032:analysis; D014018:Tissue Distribution
D003989:Dibenzoxazepines; D003903:Deuterium; D008152:Loxapine