Int. J. Vitam. Nutr. Res., 83 (1), 2013, 67 – 72 67 DOI 10.1024/0300-9831/a000146 Int. J. Vitam. Nutr. Res. 83 (1) © 2013 Hans Huber Publishers, Hogrefe AG, Bern Research Note Rapid Determination of Coenzyme Q10 in Food Supplements Using 1 H NMR Spectroscopy Yulia B. Monakhova 1,2,3 , Ingrid Ruge 1 , Thomas Kuballa 1 , Christiane Lerch 4 , and Dirk W. Lachenmeier 1,5 1 Chemisches und Veterinäruntersuchungsamt (CVUA) Karlsruhe, Germany 2 Bruker Biospin GmbH, Rheinstetten, Germany 3 Department of Chemistry, Saratov State University, Saratov, Russia 4 Chemisches und Veterinäruntersuchungsamt (CVUA) Stuttgart, Germany 5 Ministry of Rural Affairs and Consumer Protection, Stuttgart, Germany Received: May 26, 2012; Accepted: February 4, 2013 Abstract: A methodology utilizing 1 H NMR spectroscopy has been developed to measure the con- centration of coenzyme Q10 (CoQ10) in dietary supplements. For sample preparation, a very simple dilution with deuterated chloroform and addition of internal standard is sufficient. CoQ10 produces a distinct peak of the CH groups in the isoprene side chain of the molecule in the δ 5.15 – 5.05 ppm range, where it can be distinguished from other matrix compounds. The method was shown to be of adequate sensitivity with a limit of detection (LOD) of 7.8 mg/L, to control the CoQ10 content in the majority of the products. The precision expressed as relative standard deviation was around 5 %; linearity was observed from 14 to 2000 mg/L (R = 0.99). The developed methodology was applied for the analysis of 21 food supplements (capsules, tablets, and liquid products). On the basis of the labeled amounts, only two products contained substantially lower concentrations of CoQ10 (57 % and 51 %). All other concentrations varied between 83 % and 190 % with respect to labeling. The developed NMR method may be used by quality assurance laboratories for routine control of CoQ10 products. Key words: food supplements, NMR spectroscopy, CoQ10, ubiquinone Introduction Coenzyme Q10 (CoQ10) is a naturally occurring mol- ecule for which a range of potential health benefits has been postulated [1], but according to the European Food Safety Authority, a cause and effect relationship has not been established between the consumption of CoQ10 and the health claims submitted by the industry [2]. A significant number of CoQ10-containing dietary supplements are nevertheless available on the market and these products have gained increasing popularity. A key challenge therefore is to develop an analytical