Submitted to: Lipids
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/11/2001
Publication Date: 12/1/2001
Citation: Kelm, M., Flanagan, V.P., Pawlosky, R.J., Novotny Dura, J., Clevidence, B.A., Britz, S.J. 2001. Determination of 13c-labeled and endogenous beta-carotene, lutein, and vitamin a in human plasma using quantitative mass spectrometry. Lipids.36:1277-1282. Interpretive Summary: In addition to the nutritional value of betacarotene as a pro-vitamin A compound, carotenoids and related xanthophylls may possess other beneficial nutritional effects, such as those related to their antioxidant properties. In support of potential human nutrition investigations, three definitive methods utilizing (NCI) mass spectrometry were advanced for the determination of endogenous (12C-compounds) and 13C-lableled betacarotene, -lutein and -retinol (derived from the labeled betacarotene) in plasma from a subject who was fed a typical serving of 13C-labeled kale. The determination of the retinol isotopomers from plasma was carried out using labeled internal standards by GC-MS with NCI detection. Information coming from this study is of importance to nutritionists and policy-makers who are in a position to make decisions regarding the adequacy of certain nutrients present in foods to meet Americans dietary requirements.
Technical Abstract: Quantitative procedures employing liquid-chromatography / particle beam-mass spectrometry (LC/PB-MS) and gas chromatography-mass spectrometry (GC-MS) were developed for the determination of the endogenous and 13C-labeled betacarotene, -lutein and -retinol in plasma of a subject who consumed kale (Brassica oleracea), which had been grown in a 13CO2 enriched atmosphere. Betacarotene and lutein were analyzed using LC/PB-MS applying HPLC separation procedures to resolve the analytes. The concentrations of the betacarotene in the plasma over a several week period were determined using 2H8-betacarotene as an internal standard. The total plasma concentrations of all trans-lutein was quantified by HPLC analysis with UV detection using beta- apo-8'-carotenal as an internal standard and the ratio of the 13C:12C isotopomers of lutein were determined by PB-MS. The retinol isotopomers were collected from HPLC fractions of the plasma extract and then analyzed as the trimethylsilyl ethers by GC-MS. The retinol isotopomers were quantified using 2H4-retinol. These methods demonstrate the application of highly sensitive MS procedures for the determination of carotenoids and vitamin A.