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PII‐81
Author(s) -
Siluk D.,
RodriguezRosas M. E.,
Oliveira R. V.,
Wainer I. W.
Publication year - 2006
Publication title -
clinical pharmacology and therapeutics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.941
H-Index - 188
eISSN - 1532-6535
pISSN - 0009-9236
DOI - 10.1016/j.clpt.2005.12.206
Subject(s) - chromatography , chemistry , high performance liquid chromatography , acetonitrile , retinol , vitamin , extraction (chemistry) , fluorescence spectroscopy , formic acid , human plasma , fluorescence , biochemistry , physics , quantum mechanics
AIMS An on‐line extraction liquid chromatographic method with column‐switching technique and UV and fluorescence detection was developed for the determination of retinol and α‐tocopherol in human plasma. METHODS Two on‐line extraction precolumns were evaluated for the method development: GFFII ‐ glycine‐L‐phenylalanine‐L‐phenylalanine column and ADS ‐ alkyl‐diol‐silica. The study was performed by direct injection of 50 ul aliquots of human plasma sample onto RAM support where vitamins were retained while proteins and very polar compounds were washed to waste using a mixture of water and acetonitrile. The retained compounds on the pre‐column were directed in a backflush mode onto an analytical column Zorbax SB‐ C8 for separation and detection with a mobile phase consisting of acetonitrile ‐ water (95:5, v/v ). The flow rate was 1 mL/min. Vitamin A was detected at 325 nm in UV while vitamin E was detected with fluorescence at 295 nm excitation and 350 nm emission wavelengths. RESULTS A total time of analysis, including sample preparation, was 15 minutes. The retention times were approximately 9.0 min for retinol and 12.8 min for α‐tocopherol. The ADS support seemed to show less matrix effects in comparison to GFFII precolumn. CONCLUSIONS The present method will be validated and used to analyze plasma samples obtained from patients enrolled in the Baltimore Longitudinal Study of Aging. It is a promising method for clinical studies in which retinol and α‐tocopherol in human plasma are being investigated. Clinical Pharmacology & Therapeutics (2005) 79 , P57–P57; doi: 10.1016/j.clpt.2005.12.206