Oxidation reaction of tannic acid by I 2 was used in the determination of tannic acid in Chinese gall nut by ultraviolet spectrophotometry in aqueous ethanol solution, where I 2 exhibits a sensitive absorption at 289 ...Oxidation reaction of tannic acid by I 2 was used in the determination of tannic acid in Chinese gall nut by ultraviolet spectrophotometry in aqueous ethanol solution, where I 2 exhibits a sensitive absorption at 289 nm. The linear regression equation of the method is A=0.018 61+0.245 3c(mg/L) with a correlation coefficient of 0.999 8. The linear response range is 0.0~2.0 mg/L, the apparent molar absorptivity is 4.14× 10 5 L/(mol·cm) and the recovery is in the range of 97.8%~104.3%. The method has the advantages of simplicity, high sensitivity and rapidity.展开更多
文摘Oxidation reaction of tannic acid by I 2 was used in the determination of tannic acid in Chinese gall nut by ultraviolet spectrophotometry in aqueous ethanol solution, where I 2 exhibits a sensitive absorption at 289 nm. The linear regression equation of the method is A=0.018 61+0.245 3c(mg/L) with a correlation coefficient of 0.999 8. The linear response range is 0.0~2.0 mg/L, the apparent molar absorptivity is 4.14× 10 5 L/(mol·cm) and the recovery is in the range of 97.8%~104.3%. The method has the advantages of simplicity, high sensitivity and rapidity.