Chromatography Forum

My two cents regarding the ion volume:

I can't imagine that EI/CI use the same volume. Yes there are normally Dual Use Volumes but for EI you usually want an open exit volume. CI needs a closed one, so the reaction gas can't build up somewhat of an pressure inside the vacuum to reduce the EI reaction

Thanks!

I finally dug through the documentation that Scion was kind enough to send me, and indeed you're correct.

The EI volume is "open" on the end(claimed for maximum ion tranmission) and is-for all intents and purposes-a hollow tube in front of the repeller.

The CI volume caps the end off and has just as small hole so-as you said-it can build up some pressure of CI gas.

There is a difference in ion volumes. You need an ion volume change out tool thingy. I have two and only need one. We need to find a way to get you the spare one I have. Do you have any spare ion volumes? As I recall, there is an ion volume and the holder, you will need to have at least two holders on hand.

Can you email me at lbhutc01 AT louisville.edu ? (replace the AT with @ and delete the spaces-don't want to post a live email)

Thanks!

tdgcuser has set me up in good shape with a spare EI volume, a couple of CI volumes, some other odds and ends, and an insert/removal tool!

Thank you again to him!