Rapid Gas Chromatographic Assay of Serum Diazepam, N‐Desmethyldiazepam, and N‐Desalkylflurazepam

A rapid procedure for the measurement of serum diazepam (D), N-desmethyldiazepam (ND), and N-desalkylflurazepam (NF), levels in clinical samples is described. The single step extraction procedure yields quantitative extraction for the drugs mentioned above. No solvent evaporation step is needed. No interference of endogenous substances or generally used psychotropic drugs containing halogen atoms has been observed. The conditions provide excellent precision, due to a clear separation of the internal standard, medazepam, from the solvent front. The frequency response electron capture detector provides a linear response to the drugs over a 5 × 102 concentration range making serial dilution of the samples unnecessary. The automatic data reduction system indicates the serum levels directly in ng/ml without manual calculations.