褪色光度法测定硫酸庆大霉素

Fading Spectrophotometric Determination of Gentamicin Sulfate

实验研究了硫酸庆大霉素（GM）与刚果红（CR）反应生成离子缔合物的吸收光谱。在pH=6．50的介质中，刚果红与硫酸庆大霉素反应生成离子缔合物，使刚果红溶液褪色。在499nm处测其吸光度值，褪色吸光度值与硫酸庆大霉素的含量有关，从而建立了测定硫酸庆大霉素的褪色分光光度法。在最佳反应条件下，硫酸庆大霉素含量在0．25-5μg／mL范围内遵守比尔定律，检出限0．111μg／mL，相对标准偏差为1．61％，刚果红与硫酸庆大霉素反应的络合比为3：1。

The absorp tion spectrum of ion-association complex produced by the reacticn of gentamicin sulfate （GM） and Congo red （ CR ） is studied. In the medium of pH = 6. 50, Congo red reacts with gentamicin sulfate to form ion association complex, which causes the fading of Congo red solution. The absorbance value of fading is related to the content of gentamicin sulfate. Thus, according to this method fading spectrophotometric for the determination of gentamicin sulfate is established. Under the optimal conditions, Beer＇s law was obeyed in the range of GM concentration of 0. 25 - 5 μg/mL. The detection limit is 0. 111μg/mL and the relative standard deviation is 1.61%. The complexation ratio of Congo red with gentamicin sulfate reactions is 3： 1. This method is used to determine the content of gentamicin sulfate injection with satisfactory results.