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Composition of tomatoes and tomato products in antioxidants (WG1) page 85
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(From Scott 1992)
Fig 20. plasma carotenoids eluted on a Vydac TP 54 column.
a: column 2, metal frits
b: column 2, metal free frits
c: column 3, metal frits
d:column 3, metal free frits
When a new C30 polymeric column was used, a large number of carotenoids including
cis isomers were detected in human plasma and vegetable samples (Emenhiser et al. 1996).
However when a complex mixture of carotenoids was present in the samples, it was
neccessary to previously elute different fractions on Sep-Pak cartridges. It must be noted that
the recovery of α- and β-carotene from the column were less than 65% probably due to 1) the
higher interaction of these pigments with the C30 stationary phase as compared with C18
polymeric and 2) the lack of encapping of the C30 column that gives unreacted silanol groups
which are thought to degrade partially carotenoids on the column. Addition of triethylamine
(TEA), increased the carotenoid recovery by 21-55 % The mechanism is not known but
several hypotheses, including buffering of acid groups of silanols by the basic properties of
TEA, were proposed. The same positive effect on the carotenoid recovery was reported for
ammonium acetate and a mixture of TEA/ammonium acetate (Scott 1992, Emenhiser et al.