The determination of isoniazid and its metabolites acetylisoniazid, monoacetylhydrazine, diacetylhydrazine, isonicotinic acid and isonicotinylglycine in serum and urine

Abstract

1. A solvent system was devised for the extraction of isoniazid and its metabolites acetylisoniazid, monoacetylhydrazine, diacetylhydrazine, isonicotinic acid and isonicotinylglycine from serum and urine. 2. Specific chemical and fluorimetric methods were developed for the determination of the extracted isoniazid and acetylisoniazid, and chemical methods for the determination of monoacetylhydrazine, diacetylhydrazine, isonicotinic acid and isonicotinylglycine. 3. When applied to serum, these methods were capable of measuring concentrations of down to about 0.005μg of isoniazid/ml, 0.05μg of acetylisoniazid/ml, 0.2μg of monoacetylhydrazine/ml, 0.2μg of diacetylhydrazine/ml, 0.02μg of isonicotinic acid/ml and 0.1μg of isonicotinylglycine/ml. 4. In urine, these methods were capable of measuring concentrations of down to about 0.05μg of isoniazid/ml, 0.2μg of acetylisoniazid/ml, 1μg of diacetylhydrazine/ml, 0.1μg of isonicotinic acid/ml and 0.2μg of isonicotinylglycine/ml. 5. The stability of these compounds was studied in serum and urine and a method devised to decrease their decomposition in serum.