Abstract: A new method is proposed to determine ceftazidime using sodium nitroprusside. In an alkaline solution, a brown product is formed by the reaction of ceftazidime with sodium nitroprusside with the stoichiometric ratio of 1∶2. The amount of ceftazidime can be determined owing to the absorbance of the colored product. Absorbency is linear with the concentration of ceftazidime in the range of 2.50~810 mg/L, and the regression equation is A=0.02704+0.00218ρ(mg/L) with a correlation coefficient of 0.9987. The apparent molar absorption coefficient and the detection limit are 1.2×103 L/(mol·cm) and 1.38 mg/L, respectively. This method is simple and fast, the study indicated that the method could be applied to the determination of ceftazidime in injection with satisfactory results.

Key words: sodium nitroprusside, ceftazidime, spectrophotometry