Abstract: An UV-spectrophotometry determination method for pyrogallic acid content was studied. Test solution of pyrogallic acid was prepared by adding formic acid as antionxidative stabilizer, thus the measuring instability due to the oxidability of pyrogallic acid was overcome. The appropriate addition of formic acid (0.1 mol/L) into test solution was 10 mL. UV absorption peak of the test solution was determined at 266 nm. The stability of determination value, linear relationship between concentration and UV-absorbance under test condition were proved, and error of measurement was estimated. The study results indicated that this new method could be used for quantitative determination of pyrogallic acid in production for its simpleness, cheapness, veracity and stability.

Key words: pyrogallic acid, UV-spectrophotometry, quantitative determination