[A specific dosage method for the analysis of 24 antidepressants using gas chromatography-mass spectrometry (GC/SM)]

A specific and sensitive method for the analysis of 24 antidepressants in human serum was developed using gas chromatography-mass spectrometry (GC/MS). This method allowed the simultaneous determination of antidepressants belonging to different classes: tricyclic antidepressants (TADs), selective serotonin reuptake inhibitors (SSRIs) and selective inhibitors of monoamine oxidase A (IMAOs). Antidepressants were submitted to liquid-liquid extraction at pH 9.5 using a mixture of heptane/isoamyl alcohol (98.5/1.5; v/v) without derivatization. Cyproheptadine was used as the internal standard (IS). Separation was obtained with a nonpolar PTE5 capillary column (30 m x 0.32 mm; film thickness 0.25 micron). Mass spectrometry consisted of electron impact ionisation (70 eV), and full scan acquisition. Extraction recoveries were over 60% for 22 antidepressants and between 35 and 95% for moclobemide and viloxazine. Limits of quantitation ranged from 20 to 100 ng/ml for most of the antidepressants, except for moclobemide and viloxazine for which it was 500 ng/ml. Intra-assay standard deviation was satisfactory. An excellent linearity was observed from the respective LOQs up to 1000 ng/ml for 22 antidepressants and up to 4000 ng/ml for moclobemide and viloxazine.