Chromatography Forum

Hello all

I need to connect columns to Varian inlets without twisting the column - the ferrule being inside the Varian nut makes this impossible with the standard configuration. Quadrex make a quick connector with a cam action, does anyone have any experience with these ? - the price is a bit high for experimental purchases !

Are there any alternatives ?

Thanks

Peter

Sorry, no experience of my own with your setup. Is this for a two hole ferrule or is this unique for the varian column nut? If its just one column why can't you just hold the column extra steady as you are tightening the nut?

Hi aldehyde

The inlet is connected to a pre-column / cold trap with a press-fit Y at the downstream end that is part of a Deans switch. If the pre-colum twists it breaks out of the pressfit. This is a particualr problem with Varian because the ferrule sits entirely inside the nut, and rotates with it as it tightens.

Peter

Ouch that is annoying, I'm sure you're looking for a more permanent solution at the inlet but could you install inlet side first and then press it into the Y connector?

Hi aldehyde

Yes, that's how I'm doing it, connecting to the inelt and then to the switch and it works OK except for some fiddly access issues with home-built hardware. The real problem comes when it's time to disconnect; ht eferrule is stuck to the column and locked into the nut, so there is no way of stopping the pre-column twisting. Disconnecting the pressfit first works OK and sometimes I can reconnect it (Restek siltek deactivated) but I would prefer to disconnect from the inelt and leave the switch intact.

The Quadrex coupler is very high tech. A lower tech solution would be a scaled down version of a cylinder bullnose connector, but I do not have the workshop facilities to do that kind of precision engineering.

Peter