Robustness testing was performed by varying the operational
parameters, one at a time, such as flow rate, ramp temperature,
inlet temperature, oven temperature, and detector temperature.
The variability of the percentage of peak areas in fatty acid samples
is summarized in Table 9. Results showed that the percentage
differences (absolute) of the individual fatty acid content found in
the spiking solution using each of the altered GC conditions and
the procedural GC conditions were all within 70.5% of that found
from the procedural conditions. The oleic acid content found in
spiking solution obtained from each of the altered GC conditions
was within an absolute difference of 71.0% of that found from the
procedural conditions. These low percentage variation values
(absolute) revealed that the proposed method is robust.