A gas chromatogram of the organic components of a sample of beer using
a column that separates compounds on the basis of their relative
boiling points provides a GLC trace with several peaks.  Two of the
smaller peaks, with retention times of 9.56 and 16.23 minutes, are
believed to be ethyl acetate and ethyl butyrate, respectively.

Suggest 2 ways in which you could adjust the conditions of the
experiment so as to reduce the retention time for all components in
the sample.

Well met again! :)

The retention time can be reduced for all components by using a
shorter column and by increasing the temperature of the column.

Source:
“The retention time (tR) is directly influenced by the column length.
Longer columns cause higher retention times… The column temperature
influences the separation, too. An increased temperature induces a
decrease of the distribution coefficient and the retention time.”
From “Gas chromatography (GC)”
http://www.zal.tu-cottbus.de/zal/prakt/gaschrom.htm (web site of the
Brandenburg Technical University, Cottbus, Germany)

Search strategy: decrease "retention times" "gas chromatography"