Electron-capture gas chromatography of barbituric acids and diphenylhydantoin after pentafluorobenzylation.

Alkylation of barbituric acids and diphenylhydantoin with pentafluorobenzyl bromide is described; the reaction is quantitative in the presence of excess of triethylamine. The electron-capture detector response of the derivatives is high, ranging from 2 to 8 x 10(-17) moles/sec. The derivatives demonstrate excellent peak symmetry and are well suited to quantitative analysis. The structures of the derivatives have been confirmed by mass spectrometry.