Published:Journal of Chromatographic Science, ISSN 0021-9665 Volume 46, Number 1, January 2008, pp. 61-67

Determination of Caffeine and Sympathomimetic Alkaloids in Weight Loss Supplements by High-Performance Liquid Chromatography

Ronald L. Evans and Paul H. Siitonen
National Center for Toxicological Research, Food and Drug Administration, 3900 NCTR Road, Division of Biochemical Toxicology, Jefferson, AR 72079

Reversed-phase high-performance liquid chromatography utilizing photodiode array detection is used for the simultaneous determination of caffeine and nine alkaloids from Citrus aurantium (CA) and ephedra (EA) contained in dietary weight loss products. Since the Food and Drug Administration (FDA) ban of EA, manufacturers have substituted CA in their weight loss formulations, usually combined with high levels of caffeine. The alkaloids contained in CA have some physiological effects similar to those of the EA alkaloids and are, therefore, cause for concern. Caffeine has been shown to potentiate the toxicity of the EA alkaloids. Recently, a federal judge overturned the absolute ban and allowed marketing of low levels (< 10 mg/day) of total EA alkaloids. To support an absolute ban, the FDA is now compelled to perform dose-dependent toxicology studies to determine the toxic dose(s) of EA. The toxicity of the CA compounds is largely unknown, especially in combination with caffeine. The described method enables quantitation over a wide range of product formulations. Recoveries range from 91% to 100% from a variety of fortified plant matrices.

Reproduction of editorial content of this journal is prohibited without publisher’s permission.

Site Map: Home | Current Issue | Subscribe | Back Issues | About Us | Meetings | Advertising |
| Books for Sale | For the Author | Links | Supplier Info | Search |