title: Mass fragmentographic determination of diphenylhydantoin and its main metabolite, 5-(4-hydroxyphenyl)-5-phenylhydantoin, in human plasma.
abstract: A method is described for the mass fragmentographic determination of diphenylhydantoin and its main metabolite, 5-(-4-hydroxyphenyl)-5-phenylhydantoin (4-OH-DPH), in human plasma as their dimethyl and trimethyl derivatives, respectively. The derivatives are formed by using the recently described extractive alkylation technique. Pentadeuterated 4-OH-DPH is used as the internal standard. Following acidic hydrolysis of the plasma sample, conjugated 4-OH-DPH and, indirectly, the dihydrodiol metabolite, 5-(3,4-dihydroxy-1,5-cyclohexadien-1-yl)-5-phenylhydantoin, are measured. Using 100-mul plasma samples, the lower limit of detection is about 10 ng/ml 00.03 nmole/ml).
mesh_terms: D000478:Alkylation; D002849:Chromatography, Gas; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D008722:Methods; D008832:Microchemistry; D010672:Phenytoin / Q000031:analogs & derivatives* / Q000097:blood*; D013696:Temperature
chemical_list: C001419:hydroxyphenytoin; D010672:Phenytoin