Analysis of hydralazine in pharmaceutical preparations and biological fluids by gas chromatography

Gas chromatographic method was developed for the analysis of hydralazine after derivatization with ethyl chloroformate (ecf) from column db-5 (30 m × 0.32 mm id). the caliberation graph was observed within 0.05-5.0 μg/ml with limit of detection 5 ng/ml. hydrazine and isoniazid when added with hydralazine also separated completely. the derivatization and elution of hydralazine was reproducible with coefficient of variation (cv) within 0.4-1.4 % (n=5). a number of pharmaceutical additives when added did not interfere in the determination of hydralazine. the method was examined for the analysis of hydralazine in pharamaceutical preprations and spiked urine and human blood serum. the hydralazine observed concentrations agreed with expected values with rsd within 0.5-1.3 %.