Identification and quality control of Chinese medicine based on the fingerprint techniques.

Traditional Chinese medicine (TCM) contains a large number of herbal medicine and Chinese patent medicine, each of which contains many compounds that may be relevant to the medicine's putative activity. The homonym and synonym are very popular in TCM for its source complex. How to identify species and control the quality of TCM has become urgent, and fingerprint techniques have now been widely used in TCM for these purposes. In the present paper, four popular fingerprinting techniques (CE, HPLC, GC, and XRD) and their current applications in TCM are reviewed. All these techniques are proved to be an advanced and effective way to get an accurate and integral fingerprint, and each is discussed in detail with examples. CE, HPLC and GC are widely considered as the ideal methods to work out fingerprint analysis. GC is outstanding in analyzing the volatile components and HPLC has advantages in the analysis of the majority of chemical components of TCM. However, because of the complexity of chemical components in TCM, it is very hard for single CE, HPLC or GC to characterize all these components. Hyphenated techniques are strongly recommended for the purpose of quality control of TCM. It is concluded that more rational approach to the authentication and quality assessment of TCM is essential and the fingerprint techniques might be a powerful tool for quality control of TCM in the near future for their unique advantages.