Determination of lycopene in tissues and plasma of rats by normal-phase high-performance liquid chromatography with photometric detection

An analytical method for the determination of lycopene in tissues and plasm a of rats is described. The method was validated for the determination of l ycopene in liver and plasma with respect to selectivity, linearity, accurac y, recovery and precision. Following precipitation of proteins with water-e thanol plasma was extracted with hexane; tissues were extracted with aceton e followed by precipitation of proteins with water-ethanol and extraction o f lycopene with hexane. Separation and quantification of geometrical isomer s of lycopene was achieved by normal-phase HPLC with UV/VIS detection at 47 1 nm. The method proved to be selective and specific for lycopene in plasma and liver. Detector response was linear in the range from 2 ng/g to 10 mu g/g liver and 0.5 ng/ml to 2 mu g/ml plasma, respectively. Average recoveri es ranged from 96 to 101% in spiked liver samples and from 91 to 94% in spi ked plasma samples. Intra-day variability (C.V.) was less than or equal to 6% and less than or equal to 5% in liver and plasma, respectively. Inter-da y precision was less than or equal to 9% for liver samples and less than or equal to 6% for plasma samples. The procedures were successfully applied t o the sample analysis of pharmacokinetic and metabolism studies. (C) 2000 E lsevier Science B.V. All rights reserved.