Simultaneous high-performance liquid chromatographic determination of retinol by fluorometry and of tocopherol by ultraviolet absorbance in the serumof newborns.

The simultaneous determination of retinol and tocopherol by isocratic HPLC in 100 mu l serum from preterm newborns is described. Retinol (t(R) 2.02+/- 0.04 min) and retinyl acetate were detected fluorometrically, and were base line-resolved in 4 min. Tocopherol (t(R) 8.4+/-0.16 min) and tocopheryl ace tate were detected by UV absorbance. Intra- and inter-assay RSD were: retin ol, 5.6 and 8.1, and tocopherol, 3.6 and 6.7, respectively. This method is fast, selective and highly sensitive for retinol. It permits the measuremen t of serum concentrations of retinol and tocopherol with good accuracy and precision. (C) 1999 Elsevier Science B.V. All rights reserved.