Chromatography Forum

Hello,

I have soil samples containing BTEX. I want to analyze them by headspace gc-FID. Do i just put soil directly in the vial and heat it and get the vapour or do i have to dissolve the soil in something and heat that vial up. Then take vapor sample. Its an automatic headspace system with GC-FID and DB-1 column. please can anyone help me. Thank you very much in advance

There are surely standard methods you can follow - google is your friend.

Peter

You could try the same as we do using purge and trap. Add an equal weight of water to the sample ( 1g soil with 1ml water) or maybe 2ml/1g it all depends on the size of the headspace vial. Typical purge and trap is 5g per 5ml water.

The BTEX in the dissolved sample will not like to stay in the water, so it should help it volatilize into the headspace upon heating.

Sandy and Loam soils will give best recoveries, but Clay soils will always tend to adsorb even BTEX quite well.