Gas-chromatographic determination of mephenytoin and desmethylmephenytoin, after off-column alkylation.
We describe a gas-liquid chromatographic method for determining mephenytoin and its active metabolite, desmethylmephenytoin, in human serum. 5-Methyl-5-phenylhydantoin is used as the internal standard. The method involves extraction of the drugs by adsorption onto charcoal and off-column derivatization to their pentyl derivatives. Peak height and concentration are linearly related and the day-to-day CV for therapeutic concentration is about 2 to 6%. No interferences by endogenous compounds or drugs commonly used for seizure control have been encountered.
D000478:Alkylation; D002849:Chromatography, Gas / Q000379:methods; D006801:Humans; D006827:Hydantoins / Q000097:blood*; D008617:Mephenytoin / Q000097:blood* / Q000031:analogs & derivatives
D006827:Hydantoins; C014544:ethylphenylhydantoin; D008617:Mephenytoin