Analysis of tricyclic antidepressants in human plasma by GLC--chemical-ionization mass spectrometry with selected ion monitoring.

A method is described for the analysis of amitriptyline, doxepin, imipramine, nortriptyline, desmethyldoxepin, desipramine, and protriptyline in human plasma utlizing GLC-chemical-ionization mass spectrometry with selected ion monitoring. The assay is highly specific and is quantitative to at least 1 ng/ml with a standard error typically less than 5%. Representative concentrations of the parent compounds and their monodemethylated metabolites, as meeasured in plasma samples from patients under treatment with tertiary amine tricyclic antidepressants, are given.