The final column assessed for this experiment was a DB-23
(30 m 0.25 mm i.d., 0.25 mm film thickness, Agilent, Santa Clara,
USA ) consisting of a highly polar (50% cyanopropyl)-methylpolysiloxane
stationary phase and is designed for the separation of
fatty acids and esters. In a preliminary experiment, the DB-23
column only separated 12 fatty acids with poor resolution among
stearic acid (C18:0), oleic acid (C18:1) and linoleic acid (C18:2).
Based on the above column screening data, the DB-FFAP column
was found to be the best column for analysis of oleic acid and its
related free fatty acids. As such, the Agilent DB-FFAP column was
selected for further study