The botanical industry worldwide is in desperate need of methods for quality control of herbal drugs (botanical raw materials). Identification of the material and detection of possible adulterants are two of the principal analytical goals. These tasks can usually be completed easily by planar chromatography. Great advantages of HPTLC over HPLC are the speed of method development and the flexibility of being able to look for several classes of substance with very little effort. The AOAC Peer Verification Program has established a rapid means of validation of such methods on the basis of results from at least two independent laboratories. An HPTLC method is presented for identification of Echinacea species and their common adulterants. It has been developed and peer verified in accordance with the AOAC guidelines. Emphasis is placed on a fairly new concept of validating a qualitative TLC method. Finally experience with the procedure and results from each stage of the process are discussed and evaluated.
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