If you have a problem because of this I recommend cranking up the temp and 'baking' the column at it's maximum isothermal point - usually around 200-250 Celsius, but it varies from type to type, so check the manufacturer's info because heating a column too high and/or for too long will damage it permanently. Keep the heat up for about 1-2 hours, make sure the flow stays ON during this time. That will flush the column out and should get rid of any residual contamination hanging around.
Also, could you please try to give a little more descriptive title to your threads.