Patent ID: 7374901

Claim:
A method of quantifying coenzyme Q-10 and a 2-electron reduced form thereof contained in a specimen, comprising the steps of: extracting said coenzyme Q-10 and 2-electron reduced form thereof from said specimen using a water-soluble organic solvent selected from the group consisting of isopropyl alcohol and a solvent having a polarity comparable to that of isopropyl alcohol, so as to obtain an extraction liquid which contains extracted coenzyme Q-10 and 2-electron reduced form thereof; concentrating said extracted coenzyme Q-10 and 2-electron reduced form thereof using a concentration column and a first mobile phase, so as to obtain concentrated coenzyme Q-10 and 2-electron reduced form thereof; separating said concentrated coenzyme Q-10 and 2-electron reduced form thereof using a separation column and a second mobile phase which is different from said first mobile phase, so as to obtain separated coenzyme Q-10 and 2-electron reduced form thereof; reducing said separated coenzyme Q-10 using a non-coulometric cell reduction column; and detecting said reduced coenzyme Q-10 and said separated 2-electron reduced form using a detector.