Chromatography Forum

were in the market for a new column:

http://www.restek.com/restek/templates/ ... ig_id=7715

and are wondering if there are any clear advantages to an integral retention column like the integra-gap vs. restek's top-of-the-line mechanical connector, alumnaseal.

We dont have a leak detector, which is one reason i'd be more comfortable with the integral column, but considering the fact that we will be going through 4-6 columns a year, i would rather put the extra $50 per column toward a leak detector.

thoughts?

You need a leak seeker in any case to check other connections, so start saving !.

Peter

JF,

1) There are numerous ways to check for a leaky column.
2) There are numerous ways to make a column to column connection. Restek, Valco, SGE and Agilent all support various forms of column connectors. I can get you more info if you need it.
3) If the instrument is running only one application, that is to say not necessary to change columns often, then integral guard makes sense. If you need to change columns more often, either to change phase or because you trashed it, then column connector makes more sense.

Personally, I use column unions but I like to switch out columns quite often depending on the application I am working on at the moment. I have rarely had issues with this approach.

Best regards.

AIC,
if you could elaborate on practical column connector application, I'm all ears!

JF,

1) There are numerous ways to check for a leaky column.
2) There are numerous ways to make a column to column connection. Restek, Valco, SGE and Agilent all support various forms of column connectors. I can get you more info if you need it.
3) If the instrument is running only one application, that is to say not necessary to change columns often, then integral guard makes sense. If you need to change columns more often, either to change phase or because you trashed it, then column connector makes more sense.

Personally, I use column unions but I like to switch out columns quite often depending on the application I am working on at the moment. I have rarely had issues with this approach.

Best regards.

jf,

SGE makes the low volume union (PN 073550) which I used long ago with mixed results. Valco makes low thermal mass union (EU 0.5T) which I have used a bit with good results and know of someone who swears by it. Not deactivated though. Gerstel makes Graphpak 3D/2 which I have not used but I have worked with their other connectors and had very good luck. Agilent has "Ultimate union" which I have not used and was, frankly, shocked at the price. The person I know who has used this swears by the Siltite ferrules even under heavy oven cycling.

In my applications, I use a transfer line from injection valve to column (either packed or capillary) and I use a transfer line (usually) from column to detector. Most of the time I use a Swagelok 1/16 in union with graphite vespel ferrules and I install one column completely in the other. Most of my work, though, is not really high termperature stuff. I am, however, accutely sensitive to air leaks (helium ionization work) and I rarely have trouble with this set up.

Good luck and best regards.