Abstract
A mass fragmentographic method for the simultaneus determination of phenobarbital, primidone and diphenylhydantoin levels in serum was developed.An on-column methylation technique was employed for the derivltizltion and 4-methylprimidone was used as the internal standard.The three drugs and the internal standard were well separated on the gas chromatogram.
Multiple ion detection with a chlracteristic ion of elch compound (m/z 232 for phenoblrbital, m/z 218 for primidone, m/z 280 for diphenlyhydantoin and m/z 260 for the internal standard) gave quantitltively satisflctory results.The overall recoverywas 96.3±8.3% (mean±S.D.) for phenobarbital, 102.6±8.8%for primidone and 98.0±6.7%for diphenylhydantoin. Correlation coefficients of the assay results with those of enzyme immunoassay method were 0.95 for phenoblrbital, 0.97 for primidone and 0.99 for diphenylhydantoin, respectively.
The present method is applicable for monitoring drug levels in human serum.
