Botanical Ingredient Adulteration – How Commonly Used Analytical Techniques Can Be Fooled

The chemically complex nature of botanically-derived ingredients calls for unique quality control processes by suppliers, manufacturers, and producers of herbal products. One of the universal regulatory requirements in industrialized nations is the appropriate testing for identity and authenticity of botanical materials that are to be used in consumer products. Nevertheless, there have been numerous recent cases of accidental or intentional adulteration. Intentional adulteration is also referred to as economically motivated adulteration (EMA), where raw materials are intentionally substituted or diluted with undisclosed lower-quality ingredients for financial gain of the seller. Another concern is the occurrence of extracts “spiked” with various exogenous compounds, including prescription pharmaceutical drugs, to create a false sense of efficacy. This reflects a significant challenge to the global botanical medicine marketplace and, in some cases, affects consumer safety.

Suppliers of intentionally adulterated botanical ingredients try to take advantage of the lack of specificity of certain analytical methods used for identification. Examples are currently being compiled by an independent consortium of nonprofit organizations consisting of the American Botanical Council (ABC), the American Herbal Pharmacopoeia (AHP), and the National Center for Natural Product Research (NCNPR) at the University of Mississippi as part of the ABC-AHP-NCNPR Botanical Adulterants Program. Such examples include, e.g, the addition of food dyes to St. John's wort extracts to enhance the UV/Vis absorption at the wavelength used to determine hypericin contents, or the addition of rutin- or quercetin-rich materials from extraneous sources to comply with the required contents for total flavonoids in ginkgo extracts.

The limitations of various analytical techniques, such as macroscopic, microscopic, chemical, and genetic assays will be discussed using actual adulteration cases occurring in the dietary supplement and herbal medicine industry. Since most of the available methods focus on the determination of marker/active compounds, the emphasis will be on the chemical analysis.