[Quick identification and discrimination of sun-dried and sulfur-fumigated cimicifugae rhizoma by Fourier transform infrared spectroscopy].

OBJECTIVE

To develop a method for quick identification of sun-dried and sulfur-fumigated Cimicifugae Rhizoma by Fourier transform infrared spectroscopy (FTIR).

METHODS

The alcoholic and aqueous extracts of sun-dried and sulfur-fumigated Cimicifugae Rhizoma were analyzed and compared by FTIR combined with second derivative infrared spectroscopy.

RESULTS

FTIR spectra showed that there were some differences in the positions of infrared absorption peaks and the relative intensities in the alcoholic and aqueous extracts of sun-dried and sulfur-fumigated Cimicifugae Rhizoma, and the second derivative IR spectra clearly enhanced the spectral resolution of their differences. FTIR spectra showed that the new absorption peaks of Cimicifugae Rhizoma appeared and a part of original absorption peaks disappeared after sulfur-fumigation in aqueous extracts, while a lot of new absorption peaks appeared and the intensities of almost all absorption peaks significantly decreased after sulfur-fumigation in alcoholic extracts. Second derivative IR spectra showed that both sun-dried and sulfur-fumigated Cimicifugae Rhizoma extracted by water differed significantly from each other ranging from about 3 950 to 3 940 cm(-1), 3 850 to 3 800 cm(-1), 1 800 to 1 750 cm(-1), as well as from 1 400 to 1 350 cm(-1); Differences also existed between sun-dried and sulfur-fumigated Cimicifugae Rhizoma extracted by ethanol ranging from about 3 980 to 3 960 cm(-1), 3 850 to 3 800 cm(-1), and 1 500 to 1 460 cm(-1).

CONCLUSION

The FTIR method combined with the second derivative IR spectrum can be used to analyze and distinguish sun-dried and sulfur-fumigated Cimicifugae Rhizoma quickly and accurately. The developed method provides an efficient approach for the quality control of Chinese herbal medicines with its simplicity and strong specificity.