Determination of total captopril in human plasma by gas chromatography-mass spectrometry with selected-ion monitoring after reduction of disulfides.
Captopril is liberated from covalently protein-bound disulfides and other disulfide metabolites in human plasma by reduction with tri-n-butyl-phosphine. The captopril is then treated with N-ethylmaleimide, purified on XAD-2 resin, eluted with ethyl acetate, and methylated prior to its determination by gas chromatography-mass spectrometry with selected-ion monitoring. The limit of detection is 20 ng/mL of plasma.
D001682:Biological Availability; D002216:Captopril / Q000097:blood*; D004220:Disulfides; D004355:Drug Stability; D004356:Drug Storage; D005033:Ethylmaleimide; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D006801:Humans; D006863:Hydrogen-Ion Concentration; D010084:Oxidation-Reduction; D011392:Proline / Q000031:analogs & derivatives*; D013997:Time Factors
D004220:Disulfides; D011392:Proline; D002216:Captopril; D005033:Ethylmaleimide