Chromatography Forum

Do you need to plug the detector and injector that is not used? Is it possible to cause problems by running the system with the injector and detector not plugged? I have ordered a couple of nuts, but I currently don't have them in hand and I need to run a few samples using the one injector and detector only. I am just interested to know if I will put the system in danger by having so much hot air entering the injector and detector not in use.

The answer with most GCs is no. You should have independent control of the gases to the detector and injector ? Assuming you have independent control just switch off the spare injector and detector along with their gases. If for some reason your GC does not independently control the gases you can always just run and old column between the spare injector and detector ?

If one detector is an ECD it is a good idea to keep the make-up gas flowing, which will need the column connection to be plugged. You do not need a special nut for this - just use an ordinary column connector with a short piece of wire instead of the column.

Peter

My habit is to keep the extra inlet and detector plugged with a minimal (1 to 5 cc/min) amount of carrier or make up gas flowing to prevent oxidation.

great advice. I think that since the neighbouring detector and injector always heat up, it would be a good idea to have inert gas flowing all the time.

If it is setup for capillary columns just put a short piece of guard column between them with a low flow, probably the easiest fix you can do(or just a short piece of column similar to what is installed in the other position).