| Abstract: | The authors describe the analytical procedure for the rapid detection of isoniazide in the cadaveric blood and plasma using high performance liquid chromatography with a diode matrix detector (HPLC-DAD). The method is designed for toxicological and forensic medical analyses. The preliminary preparation of the samples includes protein precipitation with trichloroacetic acid, formation of isoniazide derivatives with cinnamic aldehyde, and chromatographic analysis on an Eclipse XDB-C18 column with registration of absorption at a wavelength of 340 nm. The mobile phase is a mixture of methanol and 0.05 M ammonium acetate buffer (50:50 v/v), pH 3.8. The detection limit is 0.5 mcg/ml in plasma and 1 mcg/ml in blood hemolizate. The qualitative determination is possible in a concentration range from 2 to 200 mcg/ml. Mean square deviation does not exceed 12% in a concentration interval from 2 to 50 mcg/ml. |
