Journal of the Brazilian Chemical Society
Print version ISSN 0103-5053
CHARAO, Mariele F. et al. Simultaneous quantification of lycopene, β-carotene, retinol and α -tocopherol in plasma after a simple extraction procedure: stability study and application to human volunteers. J. Braz. Chem. Soc. [online]. 2012, vol.23, n.8, pp.1441-1449. Epub July 31, 2012. ISSN 0103-5053. http://dx.doi.org/10.1590/S0103-50532012005000001.
A method for the simultaneous quantification of lycopene, β-carotene, retinol and α-tocopherol by high-performance liquid chromatography (HPLC) with Vis/fluorescence detection with isocratic elution was optimized and validated. The method consists of a rapid and simple liquid-liquid extraction procedure and a posterior quantification of extracted supernatants by HPLC. Aliquots of plasma were stored at -20°C for three months for stability study. The methodology was applied to samples from painters and individuals not exposed to paints (n = 75). The assay was linear for all vitamins (r > 0.99). Intra- and inter-run precisions were obtained with coefficient of variation smaller than 5%. The accuracies ranged from 0.29 to -5.80% and recoveries between 92.73 and 101.97%. Plasma samples and extracted supernatants were stable for 60 days at -20°C. A significant decrease of lycopene, β-carotene and retinol concentrations in plasma from exposed individuals compared to non-exposed individuals (p < 0.05) was observed. The method is simple, reproducible, precise, accurate and sensitive, and can be routinely utilized in clinical laboratories.
Keywords : retinol; α-tocopherol; lycopene; β-carotene; HPLC; liquid-liquid extraction.