Question

Which compound would likely move through a polar GC column the quickest?

hexane

pentanol

decan

1,2 dichlorobutane

heptanoic acid

Answer 1

=> If the polarity of the stationary phase and compound are similar, the retention time increases because the compound interacts stronger with the stationary phase.

=> As a result, polar compounds have long retention times on polar stationary phases and shorter retention times on non-polar columns using the same temperature.

=> In the present case, the GC column is polar, so the compounds which are non-polar eluted faster than polar compounds,this is due to polar compounds strongly bind to polar column and eluted slowly.

=> From the given compounds, pentanol, 1,2-dichlorobutane and heptanoic acid are polar. So these are eluted slowly.

=> But hexane and decane are non-polar, and hexane is more non-polar than decane, So hexane is eluted quickly in the polar column.