Study on determination of quercetin by discoloring kinetic spectrophotometry of methyl orange
LAI Xiao-qi and LUO Guo-tian(Department of Chemistry and Life Science,Gannan Teacher′s College,Ganzhou 341000)
A catalytic kinetic spectrophotometric method for the determination of quercetin was proposed,and the method was based on the catalysis of quercetin to the discoloring reaction of methyl orange oxidized by potassium bromate in the dilute sulfuric acid solution.Under the condition selected,the linear range of 0～0.05 mg/L is obtained for quercetin with the detection limit of 0.0012 mg/L and the apparent molar absorption coefficient of 4.52×10~6(L·mol~(-1)·cm~(-1).) The method was applied to the determination of quercetin in the gingko leaves and the Chinese medicine,the recovery was 95%～106.7% and the RSD of the method was less than 3.3% with satisfactory results.
【CateGory Index】： R284