Chromatography Forum

Hi All I have a question.

I have the stuff for manual SPME including the manual fiber holder, the white stand, the vial puck. It looks like I am missing the set screw from the holder the previos analyst was just using a thumb tac to lock it.

In anycase I am used to using the Gerstell MPS II with the needleheater. I am wondering if I can set up the unused rear inlet on the 6890 as a needleheater. It is not currently hooked up to anything just has a septa, liner gold seal, was set up with a column and FPD previously. What is the best way to configure it to bake out the fiber. Obviously I'd need to put in a SPME sleeve. Is there some sort of dummy column I should use to give the inlet some back pressure?

Sounds like a good plan. You can probably just plug the column connection, set a column flow of 1 ml/min and a split of 30:1 or whatever to get the flushing flow that you need. If you are running from software you will need to lie to it about there not being a column. Any open liner will do - you are not worried about tranfers of narrow inlet bands to the column.

Please, let us know how it goes.

Peter

You can probably just plug the column connection, set a column flow of 1 ml/min and a split of 30:1 or whatever to get the flushing flow that you need. If you are running from software you will need to lie to it about there not being a column. Peter

Could you elaborate on what you mean by plug the column. You mean completely block it off. In that case where will the column flow be going?

Just plug the connection where the column would go into the inlet - the usual nut with a no hole ferrule is the neatest, or use a bit of wire through the hole of an ordinary ferrule. With the inlet in split mode gas will flow down through the inlet liner, past the SPME fiber and out through the split - the absence of a column makes no difference at all to the flow through the inlet.

Peter

Then wouldn't I need to use a split liner with the bump on the bottom so that the split outlet is accessable to the gas?

Then wouldn't I need to use a split liner with the bump on the bottom so that the split outlet is accessable to the gas?

I would be amazed if any kind of liner seals gas tight against the metal at tha bottom of the inlet body, but I suppose that a split liner would give peace of mind.

Peter