Hi,
I currently have a HP 6890 GC equipped with an FID and DB-624 column. I am upgrading the instrument with a gas sampling loop and a TCD detector.
I plan to use the FID to analyse short chain alcohols/acids /hydrocarbons and the TCD to quantify H2, CO2 and CO. I am considering a Shincarbon column to separate H2 CO2 and CO and hydrocarbons.
The problem I have is that my input gas can contain any of the products simultaneously, (CO2, H2, CO, alcohols, acids, hydrocarbons and water vapour). The plan is to analyse CO2, H2 and CO in one experiment using the TCD, then swap the column and analyse the other products with a DB-624 (or another column?) using the FID.
Some questions...
Is this a practical approach?
How much water vapour can a DB-624 column handle without damaging it?
What happens if alcohols/acid enter a Shincarbon column? Will it effect the quantification of the permanent gases?
Are there alternative columns to the DB-624 that are more water tolerant?
"Are there alternative columns to the DB-624 that are more water tolerant?"
Ionic liquid columns are quite water tolerant. Our lab routinely uses ionic liquid columns for analyzing water using GC system. Check Supelco's website.
CO2 - PLOT column (or packed) with porapak Q.
If possible you can use two column system DB624 for volatiles and porapak Q as second column. Non retained on DB624 will pass to a second column with porapak Q for CO2, CO separation. For such approach you will need a valve.
For low CO concentration you will need a methanizer connected to FID.
Regards
GB
- Badges
- Science topic
- Similar topics
- Analytical Chemistry
- Column