Simultaneous analysis of retinol, six carotenoids, two tocopherols, and coenzyme Q10 from human plasma by HPLC

Lipophilic antioxidant determination is of relevance in health and diseases. Several HPLC methods exists but rare are those including coenzyme Q10 with car-otenoids, retinol and tocopherols. Here a single-step extraction was proposed for the detection of retinol, alpha and gamma-tocopherols, lutein, zeaxanthin, trans-beta-carotene, alpha-carotene, beta-cryptoxanthin and lycopene as well as coenzyme Q10. A single HPLC column was used and UV-vis diode array detection was performed. Echinenone, alpha-tocopherol nicotinate and coenzyme Q4 were employed as internal standards. Intra-assay and inter-assay precision were respectively 1.4-7.9% and 2.2-15.8%. Accuracy was validated using SRM 968e. LOD (limit of detection) and LOQ (limit of quantification) obtained were sufficient for nutritional epidemiological study and routine clinical application.