Quantitative determination of medazepam, diazepam, and nitrazepam in whole blood by flame-ionization gas-liquid chromatography.

Accurate methods are described for the qualitative and quantitative determination of medazepam, diazepam, and nitrazepam in 5 ml of whole blood. Medazepam and diazepam are analyzed intact and nitrazepam is chromatographed as its trimethylsilyl derivative by flame-ionization gas-chromatography on “1% OV-17.” A supplementary column of “2% OV-1” is used to separate nitrazepam TMS from diazepam when both are present in the same extract. Essential data given include the percentage recovery of medazepam, and the flame-ionization detector responses of diazepam and silylated nitrazepam relative to medazepam, calculated after extraction from blood and gas-chromatographic analysis. Chromatograms are illustrated of extracts of blood taken from patients on medazepam and diazepam therapy and from a patient who had taken an overdose of nitrazepam.