Single-laboratory validated method for determination of nordihydroguaiaretic acid in chaparral-containing dietary supplements |
| |
Authors: | Gay Martha L Musser Steven M |
| |
Institution: | U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, HFS-707, 5100 Paint Branch Pkwy, College Park, MD 20770, USA. Martha.Gay@fda.hhs.gov |
| |
Abstract: | Nordihydroguaiaretic acid (NDGA) occurs naturally in chaparral (Larrea tridentate Coville), a plant which commonly grows in the Southwest United States and has been used for medicinal purposes by Native Americans indigenous to that region. In addition to its traditional use as a tea, manufacturers of dietary supplements have marketed chaparral-containing products in a variety of formulations. Because of the hepatotoxicity of NDGA, and its occurrence in regulated products, we have developed a method for the determination of NDGA in dietary supplements and have tested this method in several dietary supplement formulations. Products were extracted with 80% methanol, filtered, and analyzed by high-performance liquid chromatography. NDGA was detected and determined with both a diode array detector and negative-ion electrospray. Fragmentation in the triple-quadrupole mass spectrometer was obtained by collisional activation of the M-H](-) ion. Collisional activation produced sufficient fragmentation to provide unambiguous identification. Lack of a stable isotope labeled internal standard has led us to compare quantitations based on UV detection with quantitations based on tandem mass spectrometry (MS/MS). Presence of NDGA was confirmed in several dietary supplement products. Quantitative results from the 2 detection methods were comparable for most products. The limit of quantitation using MS/MS was lower and fewer interferences were observed, although UV detection provided better linearity. |
| |
Keywords: | |
本文献已被 PubMed 等数据库收录! |
|