Study on the digitized and quantified evaluating method for super information characteristics of herbal preparation by infrared spectrum fingerprints

This paper aims to establish the infrared spectrum fingerprint (IRFP) in the absorbing region of 4,000-400 cm^-1 and its first derivative infrared spectrum fingerprints (d-IRFP) of ginkgo tablet (GT). And set up theories of the digitized and quantified evaluating method for super information characteristics by IRFPs of traditional Chinese medicine (TCM) which consists of the IRFP index, information index, fluctuation index, information fluctuation index and the quantified infrared fingerprint method (QIFM). Direct tabletting method was applied during the data collection of the IRFPs of 14 batches of GTs by Fourier transform infrared spectrometer. In terms of the digitized features, QIFM and similarity analysis of d-IRFP, sample S4 and S7 were evaluated as suspected outliers while the qualities of S1, S2, S6 and S12 were less well and the rests were relatively good. The assessing approach makes the expression and processing of superposed information in IRFP of TCM digitized simple and effective. What's more, an approach which can test total chemical contents in the complex system of TCM rapidly, simply and accurately was achieved by the application of QIFM based on IR technique. Finally, the quantitative and digitized infrared fingerprinting method was established as a novel approach to evaluate the quality of TCM.