Spectrophotometric Determination of Kanamycin Sulfate with Azo Blue

In a B-R buffer medium of pH 4.1,an ion-association complex was formed between kanamycin and azo blue,leading to a color-fading of azo blue,or in other words,a decrease of absorbanee of azo blue at its absorption maxima 552 nm.Under the optimum reaction conditions,linear relationship between the magnitude of color-fading intensity and concentration of kanamycin was found in the range of 0.1—4.0 mg·L~(-1),with value of molar absorptivity(e522)to be 7.3×10~4 L·mo1~(-1)·cm~(-1)and detection limit(3σ)to be 7.6×10~(-2)mg·L~(-1).In application of the proposed method to the determination of kanamyein in 2 samples of kanamyein sulfate injection, average values of RSD(n=7)and recovery obtained were 1.1% and 96.5% respectively.