[Direct identification of Ophiogon japonicus (Thunb.)Ker-Gawl. from its confusable varieties by second derivative FTIR spectroscopy combined with statistics].

In order to establish the theory and method for the identification of Ophiogon japonicus (Thunb.)Ker-Gawl. of traditional Chinese herbal medicines and its confusable varieties, second derivative FTIR spectroscopy was used combined with statistics. Samples were collected directly by Fourier Transform Infrared (FTIR) spectra with OMNI-Sampler. Then through converting FTIR spectra of the samples into second derivative spectra by derivative spectra software, Ophiogon japonicus (Thunb.)Ker-Gawl. could be identified from the confusable varieties with statistics. The result shows that the second derivative FTIR of Ophiogon japonicus (Thunb.)Ker-Gawl. and its confusable varieties are different, which differ greatly in 2 000-650 cm(-1) range in second derivative FTIR spectroscopy. The Ophiogon japonicus (Thunb.)Ker-Gawl. 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.