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ABSTRACT: Quantitative procedures employing liquid-chromatography/particle beam mass spectrometry (LC/PB-MS) and gas chromatography-mass
spectrometry (GC-MS) were applied to the determination of the endogenous and 13C-labeled β-carotene, lutein, and retinol in plasma of a subject who consumed kale (Brassica oleracea) that had been grown in a 13CO2-enriched atmosphere. All compounds were analyzed in the negative chemical ionization (NCI) mode using methane as the moderating
reagent gas. β-Carotene and lutein were analyzed using LC/PB-MS applying reversed-phase high-performance liquid chromatography
(HPLC) separation procedures to resolve the analytes. The concentrations of the β-carotene isotopomers in the plasma over
a several-week period were determined using 2H8-β-carotene as an internal standard. The total plasma concentrations of all trans-lutein were quantified by HPLC analysis with a photodiode array detector using β-apo-8′-carotenal as an internal standard,
and the ratio of the 13C∶12C isotopomers of lutein was determined by PB-MS. The retinol isotopomers were collected from individual HPLC fractions of
the plasma extract and then analyzed as the trimethylsilyl ethers by GC-MS in the NCI mode. The 13C-and 12C-retinol isotopomers were quantified using 2H4-retinol as an internal standard. These methods demonstrate the application of highly sensitive procedures empolying NCI MS
for the quantitative determination of carotenoids and vitamin A for the purpose of conducting metabolism studies of phytonutrients.
Lipids 04/2012; 36(11):1277-1282. · 2.13 Impact Factor
