Rapid Screening Test for the Adulteration of Herbal Supplements

Adulteration of herbal supplements is an increasing problem throughout the industry. There have been a multitude of FDA recorded recalls of herbal supplements found to contain adulterated materials, all resulting from deliberate adulteration. A rapid technique was developed to screen raw materials used to manufacture men's virility, sports nutrition and weight loss dietary supplements. Many of the adulterants of concern are active pharmaceutical materials which provide a great deal of infra-red (IR) spectral information. Fourier Transform Infra-Red (FTIR) spectroscopy with Attenuated Total Reflectance (ATR) sampling was evaluated for use in screening botanical and other ingredients for adulterants. The FTIR-ATR test was designed to search for the IR features of adulterants in the spectra of raw materials. Adulterants targeted by this technique include erectile dysfunction drugs, steroids, weight loss drugs and melamine. The screening method is easy to use, requires minimal sample preparation, and is fast and functional across a wide range of raw materials and adulterants. It is easily modified to analyze new botanical ingredients and screen for new adulterants as they emerge. The limit of detectable adulterants in ingredients was found to be in the range of 3–7.5% (w/w), depending on the ingredient and adulterant. Method reproducibility and repeatability were good. A false negative error rate of only 0.5% was obtained during routine screening of 201 ingredients. The false positive error rate, corresponding to 25% of the 201 samples, is deemed acceptable for a screening technique of this nature.

References: Champagne A, Emmel K (2011) Vib Spectros, Accepted manuscript.