The Use of Gradient HPLC with Coulometric Electrochemical Array Detection and Pattern Recognition to Study Botanical Authenticity

Although the authenticity and adulteration of botanicals continue to be major issues, there are relatively few simple methods available for the screening of large numbers of commercial batches of product. The challenge arises from the complexity and variability of genuine material combined with the unrelenting conduct of adulteration. Variety, growing region, season, ripeness, and processing methods all contribute to the variability of the authentic product, making unambiguous characterization difficult.

Currently, the most reliable and applicable authentication and adulteration methods are based on analytical chemical fingerprinting e.g., untargeted metabolomic techniques. An extension of phytochemical fingerprinting utilizes statistical approaches such as principal component analysis and pattern recognition to evaluate the authenticity of a given sample by comparing its metabolite profile with a compiled population of authenticated reference samples. HPLC with coulometric electrochemical detection is particularly suitable for generating extensive chemical fingerprints of endogenous electrochemically active metabolites that are essential to the botanical's flavor, stability, color, aroma, and purported health benefits. The potential of this approach for authenticating samples and for the detection of adulteration will be discussed in greater detail.