Quantitative determination of the absolute content of quercetin by proton nuclear magnetic resonance / 药物评价研究

ABSTRACT

Objective To establish a novel method to determine the absolute content of quercetin by proton nuclear magnetic resonance (qNMR).Methods DMSO-d6 was employed as solvent,and maleic acid as an internal standard.Proton signal peaks at δ7.50-7.58 and δ6.26 of maleic acid were served as quantification peaks.The content of quercetin is determined with qNMR in comparison with the results obtained by mass balance method.Results Linear regression of quantitative peak areas ratio (As/Ar) of quercetin-maleic acid vs mass ratio (ms/mr) yielded a correlation coefficient of 0.999 3 and a regression equation ofy =2.963 x + 0.134 1.The contents of three batches quercetin were 85.20％,84.93％,and 85.27％,the average was 85.13％ and its RSD was 0.21％.The results were generally consistent with that of mass balance methods.Conclusion This method was easy and simple to handle,and the analysis results were accurate.It could be the complementary for the mass balance method.