title: Determination of N-desmethyldiazepam in plasma by gas chromatography with an internal standard.
abstract: N-Desmethyldiazepam in plasma has been determined by gas chromatography with electron capture detection, using N-desmethyltetrazepam as internal standard and a column filled Poly-A 103 on Gas-Chrom Q. No prior transformation of benzodiazepines is necessary. The sensitivity is ca.1 ng/ml and the recovery is greater than or equal to 70%. The method is particularly suitable for the pharmacokinetic study of dipotassium clorazepate: the amount of unchanged clorazepate may be estimated from the difference between the amount of N-desmethyldiazepam present initially and the total amount of N-desmethyldiazepam obtained after acidic treatment of the sample; the method is also useful for therapeutic control and for analytical toxicology.
mesh_terms: D002849:Chromatography, Gas / Q000379:methods; D003975:Diazepam / Q000031:analogs & derivatives*; D004305:Dose-Response Relationship, Drug; D006801:Humans; D003708:Nordazepam / Q000097:blood*
chemical_list: D003708:Nordazepam; D003975:Diazepam