水杨酸在许多药品中作为抗霉菌的主药而被广泛应用。本法是基于水杨酸与醋酸铜(Ⅱ)在pH5.5～6时所形成的一种稳定的淡黄绿色络合物、用分光光度法测定水杨酸或制剂中水杨酸的一种快速、简便的方法。该淡黄绿色络合物在730nm处有最大吸收,其摩尔吸光系数为0.02×10~3/mol·cm。水杨酸在0.2～4.0mg/ml范围内服从比尔定律,其络合物可稳定30小时,在10～80℃范围内温度对吸光值无影响,90℃时吸收减弱,95℃混浊。本法的精密度为1.42％。苯甲酸 Salicylic acid is widely used as antifungal drug in many medicines. This method is based on the salicylic acid and copper acetate (Ⅱ) at pH5.5 ~ 6 when the formation of a stable yellowish green complexes, spectrophotometric determination of salicylic acid or a A fast, easy way. The yellowish green complex has the maximum absorption at 730nm, and its molar absorption coefficient is 0.02 × 10 ~ 3 / mol · cm. Beer’s law was obeyed in the range of 0.2-4.0 mg / ml. Salicylic acid was stable for 30 hours. The temperature had no effect on the absorbance at 10 ~ 80 ℃, but decreased at 90 ℃, turbid at 95 ℃. The precision of this Law is 1.42%. benzoic acid