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Subnanogram determination of fluphenazine in human plasma by gas chromatography mass spectrometry
Author(s) -
McKay G.,
Hall K.,
Edom R.,
Hawes E. M.,
Midha K. K.
Publication year - 1983
Publication title -
biomedical mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 121
eISSN - 1096-9888
pISSN - 0306-042X
DOI - 10.1002/bms.1200101004
Subject(s) - fluphenazine , chemistry , perphenazine , chromatography , mass spectrometry , levomepromazine , gas chromatography–mass spectrometry , gas chromatography , acetamide , selected ion monitoring , pharmacology , haloperidol , organic chemistry , medicine , neuroscience , dopamine , biology
Abstract A new gas chromatographic mass spectrometric procedure for the quantitation of fluphenazine in plasma is described. The method relies on the selected ion monitoring of fluphenazine ( m/z 406.1563) and perphenazine ( m/z 372.1299), the internal standard, after extraction from plasma with 5% isopropanol in n ‐pentane. Interferences by plasma constituents such as cholesterol are avoided by including an n ‐hexane wash. This wash step reduced the recovery of fluphenazine and to a greater extent perphenazine, however, it yielded an organic solution relatively free of any peaks with interfering ions. Prior to gas chromatographic mass spectrometric analysis the silyl derivatives of fluphenazine and perphenazine are prepared using N,O ‐bis(trimethylsilyl)acetamide. This procedure allows for the quantitation of as low as 78 pg of fluphenazine per ml of plasma using 2.0 ml plasma aliquots with a coefficient of variation of 4.6%. The high specificity and sensitivity demonstrated by this method allows for the first time the monitoring of plasma concentrations of fluphenazine up to 32 h following a single oral dose of 5 mg of the drug.