The separated bands were viewed under ultraviolet
light (254 nm) and the bands containing the C 18:1 trans and the
saturated fatty acids fractions were scrapped off together, thereby
allowing for the use of the internal standard in the quantification of
the C 18:1 isomers (Chardigny et al., 1996), into a vial containing
diethyl ether (5 mL). The vials were allowed to stand for 30 min
with frequent agitation and the resulting extracts were dried under
a stream of nitrogen, re-dissolved in dichloromethane and stored at 18 C