connecting two columns to a msd

I'm interested by this question as well.

Would it be possible to connect 2 columns to 1 MSD using a #Deans' Switch?

I think what possible. But need to consider several parameters: flow, id column, column temperature range....see also the topic change the column gc/ms without stopped turbo pump 

Thanks @azrael.

However, I have the problem that the columns' IDs are different. Two holes ferrule is not an option.

Basically,

- system 1 is: injector, column 1 (30m x 0.250mm x 0.25µm), MSD,

- system 2 is: Thermal Desorption unit, transfer line (ID 0.250mm), ultimate union, column 2 (50m x 0.320mm x 0.52µm), MSD.

So, whenever I have to switch system, I have to remove a column to put another. With all the risks associated with that operation. And, lately, I have not been successful because I believe the union is worn out and I have a leak.

Therefore, I would like to maintain both columns in the oven and switch from one system to another without too many operations.

The best would be a 4-way valve connecting both columns to the MSD but I don't know if any exists rated for up to 300ºC.

PS: GC is equipped with an unused extra EPC module (3 ports available)

Thanks @azrael.

However, I have the problem that the columns' IDs are different. Two holes ferrule is not an option.

Basically,

- system 1 is: injector, column 1 (30m x 0.250mm x 0.25µm), MSD,

- system 2 is: Thermal Desorption unit, transfer line (ID 0.250mm), ultimate union, column 2 (50m x 0.320mm x 0.52µm), MSD.

So, whenever I have to switch system, I have to remove a column to put another. With all the risks associated with that operation. And, lately, I have not been successful because I believe the union is worn out and I have a leak.

Therefore, I would like to maintain both columns in the oven and switch from one system to another without too many operations.

The best would be a 4-way valve connecting both columns to the MSD but I don't know if any exists rated for up to 300ºC.

PS: GC is equipped with an unused extra EPC module (3 ports available)

I think can use this:

see attach document page number 7 https://www.agilent.com/cs/library/brochures/5989-9667EN.pdf 

That's what I think as well.

A two or three way splitter with EPC.

I just received an info from an Agilent technician that a 4-way valve works but sooner or later will develop a leak.

That's too bad. It seemed like an elegant solution and easier to implement.

how you implement the solution for yourself, please tell us how it works in practice, very interesting.