The caffeine contents of dietary supplements commonly purchased in the US: analysis of 53 products with caffeine-containing ingredients
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- 作者：Karen W. Andrews ; Amy Schweitzer ; Cuiwei Zhao ; Joanne M. Holden ; Janet M. Roseland ; Mary Brandt ; Johanna T. Dwyer ; Mary Frances Picciano ; Leila G. Saldanha and Kenneth D. Fisher ; et al.
- 关键词：Caffeine ; HPLC ; UV/VIS ; Dietary supplement ; Reference material
- 刊名：Analytical and Bioanalytical Chemistry
- 出版年：2007
- 出版时间：September, 2007
- 年：2007
- 卷：389
- 期：1
- 页码：231-239
- 全文大小：167 KB
- 刊物类别：Chemistry and Materials Science
- 刊物主题：Chemistry
Analytical Chemistry
Food Science
Inorganic Chemistry
Physical Chemistry
Monitoring, Environmental Analysis and Environmental Ecotoxicology - 出版者：Springer Berlin / Heidelberg
- ISSN：1618-2650
文摘
As part of a study initiating the development of an analytically validated Dietary Supplement Ingredient Database (DSID) in the United States (US), a selection of dietary supplement products were analyzed for their caffeine content. Products sold as tablets, caplets, or capsules and listing at least one caffeine-containing ingredient (including botanicals such as guarana, yerba mate, kola nut, and green tea extract) on the label were selected for analysis based on market share information. Two or three lots of each product were purchased and analyzed using high-pressure liquid chromatography (HPLC). Each analytical run included one or two National Institute of Standards and Technology (NIST) Standard Reference Materials (SRMs) and two products in duplicate. Caffeine intake per serving and per day was calculated using the maximum recommendations on each product label. Laboratory analysis for 53 products showed product means ranging from 1 to 829 mg caffeine/day. For products with a label amount for comparison (n = 28), 89% (n = 25) of the products had analytically based caffeine levels/day of between −16% and +16% of the claimed levels. Lot-to-lot variability (n = 2 or 3) for caffeine in most products (72%) was less than 10%.