Detection of adulterated Ginkgo biloba supplements using chromatographic and spectral fingerprints.

The fingerprints of 18 commercially available Ginkgo biloba supplements, 12 samples of raw G. biloba leaves, and three G. biloba standard reference materials from the National Institute of Standards and Technology were acquired directly (no chromatography) by UV spectrometry and after separation using HPLC with a diode array detector. The fingerprints consisted of the UV spectral images, the chromatographic images, and the areas of the 21 most prominent chromatographic peaks. Data were analyzed by principal component analysis and one-class soft independent modeling of class analogy (SIMCA). It was determined that three of the commercial products were adulterated with rutin, four with quercetin, and one with an unidentified flavonol glycoside. One-class SIMCA of the authentic products allowed the adulterated products to be easily distinguished using Q-residuals. Authentic supplements and raw leaf materials were easily distinguished. The finely powdered samples were also analyzed by near-IR (NIR) spectrometry. The authentic and adulterated products could not be distinguished by NIR spectrometry because of the excipients.