Simultaneous determination of retinol, alpha-tocopherol and retinyl palmitate in plasma of premature newborns by reversed-phase high-performance liquid chromatography.
A reversed-phase high-performance liquid chromatographic method is described for the simultaneous determination of retinol, alpha-tocopherol and retinyl palmitate in plasma. Plasma containing an internal standard (tocol) was deproteinized with ethanol, then extracted with n-hexane. The organic layer was removed and evaporated under a nitrogen stream, and chromatographed on a reversed-phase RP-18 column using a water/acetonitrile-ethyl acetate/2-propanol gradient solvent system over 15 min at 305 nm. The recovery exceeded 93%. The detection limit was 0.1 microgram/ml for retinol, 1.3 micrograms/ml for alpha-tocopherol and 0.95 micrograms/ml for retinyl palmitate. The reproducibility, precision (expressed as coefficients of variation) and accuracy were less than 8% for all analytes. The small sample requirement, the simplicity of extraction, the short run-time and the good reproducibility make this procedure particularly useful for monitoring retinol and alpha-tocopherol supplementation in premature newborns.
Bortolotti
A
A
Perinatal Clinical Pharmacology Unit, Istituto di Richerche Farmacologiche Mario Negri, Milan, Italy.
Lucchini
G
G
Barzago
M M
MM
Stellari
F
F
Bonati
M
M
D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004224:Diterpenes; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature / Q000097:blood*; D012016:Reference Values; D015203:Reproducibility of Results; D000084562:Retinyl Esters; D013056:Spectrophotometry, Ultraviolet; D014801:Vitamin A / Q000031:analogs & derivatives* / Q000097:blood*; D014810:Vitamin E / Q000097:blood*
D004224:Diterpenes; D000084562:Retinyl Esters; D014801:Vitamin A; D014810:Vitamin E; C014794:retinol palmitate