3.2. Method validation
3.2.1. Specificity
Specificity of the method was evaluated by recording chro-
matograms of analytical standard Food Industry FAME, 37 components
in methylene chloride on both columns using the same
chromatographic condition except for the carrier gas flow which
was 1 mL/min for DB-225ms column and 1.5 mL/min for DB-23
column. The obtained chromatograms are shown below. Fig. 1
is the chromatogram obtained after injecting the analytical standard
on DB-225ms column and Fig. 2 is the chromatogram obtained
on DB-23 column.
The resolution between elaidic and oleic acid was critical. The
obtained resolution of trans and cis oleic acid using DB-225ms column
was 1.3 and more than 2 for all other peaks. Analysis on DB-
23 column gave a resolution of 2.9 for elaidic and oleic acid after
optimization. Different retention times and elution orders of
FAMEs on two tested columns gave us confirmation of the identity
of those peaks. Routine samples of pumpkin seed oil and analytical
standards AOCS#1 were analyzed according to the method on both
columns. There was no significant difference between the obtained
results for major and for minor constituents.