Indirect simultaneous kinetic determination of semicarbazide and hydrazine in micellar media by H-point standard addition method

H-point standard addition method (HPSAM) is suggested as a simple and selective method for the determination of semicarbazide and hydrazine. The reduction of Cu2+ to Cu+ by semicarbazide and hydrazine in the presence of neocuproine (Nc) and the subsequent complex formation between Cu+ and Nc produced a sensitive spectrophotometric method for indirect determination of semicarbazide and hydrazine. The difference in the rate of reduction of Cu2+ with semicarbazide and hydrazine in cationic micellar media is the basis of this method. Semicarbazide can be determined in the range of 0.5–3.75 μg ml−1 with satisfactory accuracy and precision in the presence of excess hydrazine. The proposed method was successfully applied to the simultaneous determination of semicarbazide (0.5–3.75 μg ml−1) and hydrazine (0.5–5 μg ml−1) and also to the selective determination of semicarbazide in the presence of hydrazine in several synthetic mixtures containing different concentration ratios of semicarbazide and hydrazine.