Pre-column derivatization with fluorescamine and high-performance liquid chromatographic analysis of drugs. Application to tocainide.
The quantitative determination of tocainide, a new antiarrhythmic agent, by high-performance liquid chromatography (HPLC) is reported. The drug and a chemically similar internal standard were extracted from blood plasma with acetonitrile under salting-out conditions obtained by saturation of the aqueous medium with sodium chloride-sodium carbonate. The organic extract, without evaporation, was treated with borate buffer (pH 8.2) and fluorescamine. The resulting derivatives were chromatographed on an ODS reversed-phase column using a methanol-phosphate buffer (pH 7.0) mixture as mobile phase and were detected fluorometrically by monitoring the emission at 485 nm, with excitation at 395 nm. The intra-assay coefficients of variation were 3.0 and 4.3% for ten replicate 0.25 and 1.00 microgram/ml samples, respectively, and the inter-assay coefficient of variation was 3.6% for ten replicate 1.00 microgram/ml samples. The procedure is simple, rapid, sensitive, and specific. Several other drugs and drug metabolites also were derivatized with fluorescamine and chromatographed successfully. Pre-column derivatization with fluorescamine followed by HPLC with fluorometric detection may have significant advantages in drug analysis.
D000889:Anti-Arrhythmia Agents / Q000097:blood*; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D005450:Fluorescamine; D006801:Humans; D008012:Lidocaine / Q000031:analogs & derivatives* / Q000097:blood; D013050:Spectrometry, Fluorescence; D016677:Tocainide
D000889:Anti-Arrhythmia Agents; D016677:Tocainide; D005450:Fluorescamine; D008012:Lidocaine