Identification of American ginseng from different regions using FT-IR and two-dimensional correlation IR spectroscopy

The American ginsengs (Radix panacis Quinquefolii) of different geographical regions from Beijing (China), Toronto (Canada), Vancouver (Canada), Wisconsin (USA), and the wild American ginseng can be discriminated and identified by using Fourier transform-infrared spectroscopy (FT-IR) and two dimensional correlation infrared spectroscopy (2D-IR). The FT-IR spectra of the five kinds of American ginseng have small differences. and their secondary derivative spectra have obvious finger-print feature, especially in the range of 1750-400 cm(-1). Using the difference of the position and intensity of the special (peculiar) bands, which include both the peak at 1317 cm(-1) assigned to oxalate group, and other peaks near 1050, 1020, and 866 cm(-1) assigned to the starch. we can identify and discriminate them from each others. Furthermore, using the pattern of 2D-IR correlation spectra under thermal perturbation, we can very directly identify and discriminate them. As a result, the macroscopic IR finger-print method, which combines three-steps: general IR spectra, secondary derivative spectra as well as 2D-IR correlation spectra. can discriminate different American ginsengs effectively. fast. and nondestructively. (C) 2004 Elsevier B.V. All rights reserved.