Rapid determination of coenzyme Q10 in food supplements using 1H NMR spectroscopy.
A methodology utilizing 1H NMR spectroscopy has been developed to measure the concentration 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.
Chemisches und Veterinäruntersuchungsamt (CVUA) Karlsruhe, Germany, and Bruker Biospin GmbH, Rheinstetten, Germany, and Department of Chemistry, Saratov State University, Saratov, Russia.
Yulia B
YB
Monakhova
Ingrid
I
Ruge
Thomas
T
Kuballa
Christiane
C
Lerch
Dirk W
DW
Lachenmeier
D019587:Dietary Supplements / Q000032:analysis*; D057230:Limit of Detection; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D013997:Time Factors; D014451:Ubiquinone / Q000031:analogs & derivatives* / Q000032:analysis
D014451:Ubiquinone; C024989:coenzyme Q10
CoQ10; NMR spectroscopy; food supplements; ubiquinone