Determination of beta-carotene in plasma, blood cells and buccal mucosa by electrochemical detection.

The beta-carotene concentrations in plasma, blood cells and buccal mucosal cells were determined by high-performance liquid chromatography with electrochemical detection. This method was 1,000 times more sensitive than the conventional spectrophotometric method. Polymorphonuclear cells and red blood cells had lower beta-carotene levels than the other cells. After oral administration of 580 mg/day of all-trans beta-carotene to human male volunteers for a week, the beta-carotene concentrations in all cell types increased at least several times above the original levels.