Quantitative determination of coenzyme Q10 in human blood for clinical studies

A quantitative method for the determination of coenzyme Q10 (CoQ10) in human blood has been devised which allows recovery of essentially 100% of the CoQ10. The use of whole blood rather than plasma includes the CoQ10 in white cells. The method utilizes TLC instead of saponification to fractionate lipid impurities, because CoQ10 is sensitive to saponification, and utilizes CoQ11 as an internal standard which is advantageous over CoQ9 and a synthetic quinone. The final step of HPLC frequently reveals a peak with a retention time like that of CoQ9 which, being less than that of CoQ10, can be near other peaks of impurities.