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I ran a series of alcohols; 1-pentanol, 1-hexanol, 1-heptanol, 1-octanol; through a GC with a polar column. For this particular column:
-Polar molecules are held back more (true with polar columns)
-Higher boiling molecules are held back more (true with all GCs)
The problem is that these rules go against each other. The elution order based on polarity would be octanol, heptanol, hexanol, then pentanol because smaller molecules are more polar (ethanol dissolves in water, pentanol does not). The elution order based on boiling points would be pentanol, hexanol, heptanol, octanol because bigger molecules have higher boiling points.
The lowest boiler of the bunch is pentanol, and that was at something like ~170C iirc. The injector and detector were 250C, the column itself was 75C. I'm not sure if this low temperature means the boiling point has more or less importance. When I ran decane, undecane, and dodecane through a nonpolar column, there was a very large difference in elution times and they were based solely on boiling point since each of those alkanes have basically the same nonpolarity.
-Polar molecules are held back more (true with polar columns)
-Higher boiling molecules are held back more (true with all GCs)
The problem is that these rules go against each other. The elution order based on polarity would be octanol, heptanol, hexanol, then pentanol because smaller molecules are more polar (ethanol dissolves in water, pentanol does not). The elution order based on boiling points would be pentanol, hexanol, heptanol, octanol because bigger molecules have higher boiling points.
The lowest boiler of the bunch is pentanol, and that was at something like ~170C iirc. The injector and detector were 250C, the column itself was 75C. I'm not sure if this low temperature means the boiling point has more or less importance. When I ran decane, undecane, and dodecane through a nonpolar column, there was a very large difference in elution times and they were based solely on boiling point since each of those alkanes have basically the same nonpolarity.
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