High-sensitive determination of coenzyme Q(10) in iodinate-beta-cyclodextrin medium by inclusion reaction and catalytic polarography.
A novel polarographic method for the determination of coenzyme Q(10) in beta-cyclodextrin (beta-CD) and iodinate system is proposed. The stability of coenzyme Q(10) to light was improved by the formation of coenzyme Q(10)-beta-CD inclusion complex. In addition, the sensitivity for the determination of coenzyme Q(10) was enhanced by both the formation and the polarographic catalytic wave of the inclusion complex in the presence of iodinate. In 0.1 mol/L HAc-NaAc (pH 4.7)-5.0 x 10(-5) mol/L beta-CD-1.2 x 10(-3) mol/L potassium iodinate-ethanol/water (60:40, v/v) medium, coenzyme Q(10)-beta-CD inclusion complex yielded a sensitive association/parallel catalytic wave. The second-order derivative peak current of the catalytic wave was proportional to coenzyme Q(10) concentration in the range of 6.0 x 10(-8)-2.5 x 10(-7) mol/L, and the detection limit was 1.0 x 10(-8) mol/L. The proposed method has high analytical sensitivity and is allowed to determine coenzyme Q(10) under light.
Yang
Hai-Ying
HY
Institute of Analytical Science, Northwest University, Xi'an 710069, People's Republic of China.
Song
Jun-Feng
JF
D002384:Catalysis; D003067:Coenzymes; D004795:Enzyme Stability; D006863:Hydrogen-Ion Concentration; D007452:Iodates / Q000494:pharmacology*; D008027:Light; D011048:Polarography / Q000379:methods*; D017680:Potassium Compounds / Q000494:pharmacology*; D012680:Sensitivity and Specificity; D013997:Time Factors; D014451:Ubiquinone / Q000031:analogs & derivatives* / Q000032:analysis / Q000187:drug effects / Q000528:radiation effects; D047392:beta-Cyclodextrins / Q000494:pharmacology*
D003067:Coenzymes; D007452:Iodates; D017680:Potassium Compounds; D047392:beta-Cyclodextrins; D014451:Ubiquinone; C024989:coenzyme Q10; C039693:potassium iodate