Determination of ubidecarenone (coenzyme Q10, ubiquinol-10) in raw materials and dietary supplements by high-performance liquid chromatography with ultraviolet detection: single-laboratory validation

Abstract

A method based on high-performance liquid chromatography with ultraviolet detection has been developed to quantify ubidecarenone [coenzyme Q10 (CoQ10)] in raw materials and dietary supplements. Single-laboratory validation has been performed on the method to determine repeatability, accuracy, selectivity, limits of detection and quantification (LOQ), ruggedness, and linearity for CoQ10. As CoQ10 can exist as the biologically active reduced form, the application of an oxidizing agent, ferric chloride, drives the equilibrium mechanics to the fully oxidized state and allows for exact quantification of total CoQ10 in the sample. This method was found to be fit and linear for the testing of materials containing CoQ10 in the range of approximately equal 50-1000 mg/g. Repeatability precision for CoQ10 was between 2.15 and 5.00% relative standard deviation. Observed recovery of CoQ10 was found to be between 93.8 and 100.9%. LOQ was found to be 9 microg/mL. Further, limited studies showed that some adulterants and degraded material could be satisfactorily separated from CoQ10 and identified.

Figure 1

Structure of CoQ10, vitamin K, and vitamin E.

Figure 2

Structure of reduced forms of CoQ10.

Figure 3

Structure of idebenone.

Figure 4

Typical standard chromatogram of CoQ10.

Figure 5

Linearity.

Figure 6

Percent residuals.

Figure 7

Chromatogram of CoQ10 and idebenone.

Figure 8

Chromatogram of CoQ10 and CoQ9.

Figure 9

Chromatogram of negative control with β-carotene using acetate form of vitamin E.