Chromatography Forum

I am thinking about switching to a .53 guard column (larger surface area = better deposition/longer protective lifetime of/from non-volatiles), but I am using a .32 true column. I will join them with one of Agilent's deactivated glass junctions.

I sometimes have trouble sealing leaks at the junction when using .32 guard/.32 true column, and I think this problem will be exacerbated when increasing the local pressure at the junction by incorporating a .53/.32 union.

Do any of you use wider guards than your actual column and if so do you experience leaks?

Thanks,

Luke

I have gas flow switches with three different diameters of fused silica connected with Siltek Y connectors (Restek). Once they are put together properly they do not leak.

Peter

Cool, thanks! I guess I will order the parts and give it a shot then.

Cheers,

Luke

zeroAir,

I have use a 0.53 to 0.25 in the past with the idea that I take more out of the inlet but still do 0.25 chromatography. Having said that, I used a glass press fit but I glued it. I also, always, recommend you do all of this with nothing hooked up so you are not fighting gas pressure while trying to make the seal.

Best regards,

AICMM

AICMM, thanks for the reply. Did you try doing that union without the glue?

AeroAir,

When I do press fits (not to often anymore) I always use glue. You might also consider other types such as Restek's or Gerstel's view type unions. These use ferrules to maintain pressure on the press seal.

Best regards,

AICMM