Quantitative determination of ligustilide by ~1H-nuclear magnetic resonance spectroscopy

Objective:To develop a method for the quantitative determination of ligustilide.Method:~1H NMR spectra were obtained in CDCl_3 with a Bruker AV -600 MHz spectromrter at 300 K.For each sample,8 scans were recorded with pulses width 13.8μs and delay time 2 s.Results:The integration of proton signals atδ6.25 of ligustilide andδ6.40 of coumarin could be used for the quantification.Linear regression of quantitative peak areas ratio (A_s/A_s,Y) of ligustilide - coumarin versus mass ratio(m_s/m_r,X) yielded a correlation coefficient of 0.9991 and regression equation of Y = 0.0263 +0.6676X,the precision RSD was 0.44%(n =6).The contents of 3 batchs ligustilide were 87.34%,88.63%,90.25%,respectively.Conclusion:The results showed that ~1H NMR can be used for the quantitative determination of ligustilide without reference substance.This method is reliable,rapid,accurate and simple.