title: Simultaneous determination of low plasma concentrations of retinol and tocopherols in preterm infants by a high-performance liquid chromatographic micromethod.
abstract: A method for the simultaneous determination of low concentrations of retinol and tocopherols from 100 microliters plasma using isocratic reversed-phase HPLC is described. Retinol is quantified with a programmable UV-Vis detector, whereas tocopherols are quantified by fluorescence detection using tocol as the internal standard. Intra- and inter-assay precision are 3.7 and 4.3% for retinol and 2.3 and 6.1% for alpha-tocopherol, respectively. The accuracy as determined with standard material from the US National Institute of Standards and Technology with low, medium and high concentrations is in the range of 0.2-6.0% bias for retinol and of -3.0 to 5.5% for alpha-tocopherol, respectively. This method is highly sensitive and selective and has a good precision and accuracy for measuring low concentrations of vitamins in small plasma volumes.
authors.affiliation: Laboratory of Metabolism and Nutrition, Kinderpoliklinik, Ludwig-Maximilians-University Munich, Germany.
authors.forename: Y
authors.initials: Y
authors.lastname: Göbel
authors.forename: C
authors.initials: C
authors.lastname: Schaffer
authors.forename: B
authors.initials: B
authors.lastname: Koletzko
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D002940:Circadian Rhythm; D005312:Fetal Blood / Q000737:chemistry*; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature / Q000097:blood*; D016014:Linear Models; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013056:Spectrophotometry, Ultraviolet; D014801:Vitamin A / Q000097:blood*; D014810:Vitamin E / Q000097:blood* / Q000145:classification
chemical_list: D014801:Vitamin A; D014810:Vitamin E