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Determination of carprofen in blood by gas chromatography chemical ionization mass spectrometry
Author(s) -
Hodshon B. J.,
Garland W. A.,
Perry C. W.,
Bader G. J.
Publication year - 1979
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.1200060803
Subject(s) - chemistry , mass spectrometry , chromatography , chemical ionization , gas chromatography , selected ion monitoring , gas chromatography–mass spectrometry , diazomethane , isotope dilution , thermal ionization mass spectrometry , analytical chemistry (journal) , ion source , ionization , ion , organic chemistry
A gas chromatographic chemical ionization mass spectrometric assay has been developed to measure carprofen in blood. The method features the addition of either a structural or stable isotope analog internal standard to plasma prior to a simple benzene extraction at pH 4.5. The residue, after removal of the benzene, is methylated with ethereal diazomethane. Following evaporation of the methylating solvents, a portion of the reconstituted residue is analyzed by gas chromatography mass spectrometry. The mass spectrometer is set to monitor in the gas chromatographic effluent the [MH] + ions of carprofen methyl ester and the methyl ester of internal standard generated by isobutane chemical ionization. Assay sensitivity is 5 pmol ml −1 . When 200 pmol ml −1 samples are analyzed using a stable isotope analog as the internal standard, the precision and accuracy are both 4%. Using a structural analog as the internal standard, the assay was neither as precise nor as accurate.