Do I cool inlet and interface overnight?

[zimanli]

Greetings,

I am new in GC/MS. I would like to ask a roobie question:
What temperature and pressure shall I set for oven, inlet, and interface for overnight? What shall I pay attention to when I go home?

[Rafael Chust]

For overnight purposes, I only reduce the flow rate and keep everything as settled for analysis.

In this way, I save time for next morning, avoid any sort of condensation and keep "cleaning" the system...

[zimanli]

Thank you so much for your reply. I usually set my oven temperature 35 C, inlet 250, interface 250 etc. but I notice that the system is really dirty each morning I come in. Shall I inclease the oven temperature for overnight?

[Rafael Chust]

I would do so with overnight temp being the first temp of program.

Anyway, you might need further cleaning, if your samples are dirty!

[KC]

I agree with Rafael. I would not turn temps down. Probably would not even reduce flows but thats not a bad idea.

[Rafael Chust]

Flow reduction is something I have always in mind because of cost and logistics of gases here in Portugal.

Gas generators are a rarity - I know one single company that use it! - and the local suppliers of special gases are rare and expensive!

If gas consumption is not a major concern, I would do as KC and keep the flow rate at analysis level - even overnight.

Repeating a very funny although clever phrase written in this forum: never trouble troubles until troubles trouble you!

[zimanli]

never trouble troubles until troubles trouble you! It is a good one. Thanks