Method and system for reducing the effects of column bleed carryover

A gas chromatography (GC) system, comprising:

• a GC column;
• a carrier gas source configured for flowing a mixture of a sample and a carrier gas through the GC column;
• a heating device configured for heating the GC column;
• and
• a controller configured for:
• controlling the carrier gas source to flow the mixture through the GC column during a sample run time;
• controlling the heating device to heat the GC column during the sample run time according to a heating program, the heating program comprising increasing a column temperature of the GC column from an initial temperature to a final temperature;
• and
• controlling the heating device to cool the GC column after the sample run time according to a cooling program, the cooling program comprising:
• decreasing the column temperature from the final temperature to a dwell temperature;
• holding the column temperature at the dwell temperature for an isothermal dwell time;
• and
• after the isothermal dwell time, decreasing the column temperature from the dwell temperature to the initial temperature.

A method for performing gas chromatography (GC) on a sample, the method comprising:

• flowing a carrier gas through a GC column;
• during a sample run time, heating the GC column to a predetermined temperature or according to a predetermined temperature profile;
• during the sample run time, injecting the sample into the flowing carrier gas to produce a mixture of the sample and the carrier gas, and flowing the mixture through the GC column;
• after the sample run time, cooling the GC column during a cooling time;
• and
• during at least an initial portion of the cooling time, reducing or ceasing the flowing of the carrier gas through the GC column.