Determination of carbohydrazide by high performance liquid chromatography with precolumn derivatization

The content of carbohydrazide was determined by derivatization with benzaldehyde followed by high performance liquid chromatography. The effects of the distribution proportion of the mobile phase, pH value and reaction time on derivatization were studied. Carbohydrazide derivative was separated on a Kromasil C₁₈ (250 mm x 4.6 mm, 5 mm) column using acetonitrile 5 mmol/L phosphate buffer as mobile phase with a flow rate of 1 mL/min and detected at 310 nm within 8 min. The derivatization process took place at room temperature for 30 min. The limit of detection is 0.13 mg/L, recovery of carbohydrazide is 105% and RSD < 1%. This method has been applied to the determination of the qurity of carbohydrazide with satisfactory results.