Determination of Primidone by Electron-Capture Gas Chromatography

Abstract

A method for the determination of primidone (Mysollne) In microvolumes (l.e., 50-100 μL) of serum is described. The procedure involves the derivatization of primidone with pentafluorobenzoyl chloride to form a product that Is extremely sensitive to the electron-capture detector of a gas chromatograph. Mass spectrometric data show the product to be a diamlde Involving both nitrogen atoms of the primidone heterocyclic ring. The extraction process Is a one-step operation utilizing 20% ethyl acetate in toluene (benzene) as the extracting solvent and ammonium sulfate to effect a saltlng-out of the primidone from the biologic matrix. Recovery of primidone Is greater than 92% and the coefficient of variation between analyses Is usually less than 1.0%. Quantitation Is based on the utilization of “p-methyl primidone” as the Internal standard. © 1977, American Chemical Society. All rights reserved.