Simultaneous determination of retinol, beta-carotene and alpha-tocopherol in adipose tissue by high-performance...

A method is described for evaluation of fat-soluble vitamin in human adipose tissue with the aim to obtain, accurately and within the shortest analysis time, a time-integrated measure of exposure to vitamins from the diet. Fat tissue was deproteinized with ethanol and extracted with n-hexane. Normal-phase HPLC was performed in a Lichrosorb Si60 column with a gradient of n-hexane-2-propanol at 1 ml/min. Detection was accomplished using a diode-array system (for retinol and beta-carotene) in series with a fluorescence detector (alpha-tocopherol). The method was validated and applied to human adipose tissue in a total of 140 subjects. The mean contents found were 0.43, 0.84, 240.3 microg/g for retinol, beta-carotene and alpha-tocopherol, respectively. The method is sensitive enough for detecting the compounds in 1.6 mg of adipose tissue considering the lowest concentration found.