Chromatography Forum

Hi
is there any limitation for connecting a Deans switch valve to two columns and One FID detector? because i heard that it must be connected to 2 detectors.
Thanks

What is your exact application?

Right now, I'm having a hard time understanding how you will use it with 2 columns and 1 detector. You may not need the Dean's Switch at all.

I have a GC that has 2 inlets and 1 detector but I just use a simple Y splitter (used in reverse) to pipe them to the single detector. Use small-bore transfer tubing to get from the splitter to the FID. I can inject on a HP-5 on the back inlet and a DB-Wax on the front inlet, and use the same FID - just only one column at a time.

I use Dean's Switches on 4-5 of my systems but it's for employing heartcuts from one stationary phase separation (DB-5) to another (Wax). You can get some selectivity enhancement on coeluters. In this configuration it's also essential that you have 2 detectors.

I presume that you want to select which of the two columns feeds to the FID ? It could be done, but unless you are supernaturally good at controlling flows and pressure you woul dhave to live with some loss of peak area.

Peter