[Determination of serum or plasma alpha-tocopherol by high performance liquid chromatography: optimization of operative models].
A previous multicentric study set up by the Société française de biologie clinique has emphasized the usefulness of a standardized procedure for the determination by high performance liquid chromatography of alpha-tocopherol in serum or plasma. In our study, we have tested every step of the different published procedures: internal standard adduct, lipoprotein denaturation and vitamin extraction. Reproducibility of results was improved by the use of tocol as an internal standard when compared to retinol or alpha-tocopherol acetates. Lipoprotein denaturation was more efficient with ethanol addition than with methanol and when the ethanol/water ratio was > or = 0.7. Use of n-hexane or n-heptane gave the same recovery of alpha-tocopherol. When organic solvent/water ratio was > or = 1, n-hexane enabled to efficiently extract, in a one-step procedure, the alpha-tocopherol from both normo and hyperlipidemic sera. Performances of the selected procedure were: detection limit: 0.5 microM--linear range: 750 microM--within run coefficient of variation: 2.03%--day to day: 4.76%. Finally, this pluricentric study allows us to propose an optimised procedure for the determination of alpha-tocopherol in serum or plasma.
Jezequel-Cuer
M
M
Laboratoire de biochimie A, hôpital Bichat, Paris, France.
Le Moël
G
G
Mounié
J
J
Peynet
J
J
Le Bizec
C
C
Vernet
M H
MH
Artur
Y
Y
Laschi-Loquerie
A
A
Troupel
S
S
D002851:Chromatography, High Pressure Liquid / Q000379:methods* / Q000592:standards; D006801:Humans; D012997:Solvents; D014810:Vitamin E / Q000097:blood*
D012997:Solvents; D014810:Vitamin E
Dosage de l'alpha-tocophérol sérique ou plasmatique par chromatographie liquide haute performance: optimisation du mode opératoire.