[Quality control of Corydalis Yanhusuo W. T. Wang by second derivative FTIR spectroscopy combined with statistics].

A new method using single reflection Fourier transform infrared spectroscopy was proposed for direct and fast determination of Corydalis yanhusuo W. T. Wang of traditional Chinese herbal medicines and its confusable varieties. Data were collected directly for Fourier transform infrared spectra with OMNI sampler. Then through converting FTIR spectra of the samples into second derivative spectra by derivative spectra software, it is possible to identify Corydalis yanhusuo W. T. Wang from the confusable varieties with statistics. The result shows that the second derivative FTIR of Corydalis yanhusuo W. T. Wang and its confusable varieties are different in the 2 050-650 cm(-1) range. The probability is less than 0.01 and the result is significant. Corydalis yanhnsuo W. T. Wang and its confusable varieties can be identified by identifying the inner layer parts of the cuticles of samples by second derivative FTIR spectroscopy with statistics directly, rapidly and accurately.