[Mr.Me]

Dears, I'm working in MTBE standard solution. But when I started new method to keep the MTBE in some type of vials in the refrigerator I started face some problems with injected MTBE standard solution results. I think the problem comes from the type of vials which I use it. I'm trying to have the best type used for MTBE chemical.
As you know the MTBE is volatile Chemical and used to react with the cap of the vial even the polypropylene cap. Please advise me to the best type of vials can I solve my problem with.

[MissPhosgene]

Hello. Do you mean methyl tert-butyl ether?

I would look into other sources of the problems you are coming across. I had to go through tons of methyl tert-butyl ether a few months ago, and I never had any problems with it reacting with polypropylene containers. The degredation you are seeing could be the result of exposure to light, but I would doubt it... there is a window right near my hood and when it's not raining plenty of sunlight comes in. 

If you really think it is the cap, you could put a septum on the vial instead and parafilm it to make a seal...