Chromatography Forum

Hi there
I'd like to have some advice on the best way to split a column to 2 detectors.
I've tested the Y glass connectors but it seems not totally leak-proof, any other suggestion?

Thanks a lot in advance.

Atom

The splitter you use depends on whether you are splitting between two atmospheric detectors (e.g. FID and ECD) or between an atmospheric detector and an MS, which is under vacuum.

SGE produces some good splitters, I'm using their FID/MS splitter:

http://www.sge.com/products/capillary-column-splitters

Thanks for the tip.
I want to split my column to FID and NPD.

Hi

If you have concerns regarding active compounds I can reccommend RESTEKs siltek deactivated Y press tight connector.
Worked great when I analysed higly brominated BDEs that are sensible to free sinol groups and also used it succesfully when splitting to uECD/FID on an Agilent system.

Glass press-fits are critically sensitive to the quality of the cut at the end of the column. If you are having leak problems you probably need to look at the quality of the cut. Also it is a good idea to connect both the splitter legs to the detectors beore you connect the legs to the Y, then there is no chance of the silica leg twisting as you tighten the detector nut.

Peter

At_om,

If reactivity is an issue, then a glass splitter might be the best path. Gerstel makes y splitters as does Restek which use ferrule supports after the press fit to ensure a good seal. It has been a while since I have used the Gerstel but more recently the Restek and I have had very good luck with both. Press fits are also an option but I have always had to glue these. On the detector end there should be significantly less pressure on the system so that might not be necessary but I would still glue it. Another option is a silico steel T (Restek makes it). Band broadening might go up a bit but would only affect you if you have very complicated separations.

If reactivity is not an issue then a simple 1/16 T will work (have done it numerous times) and will be very easy and inexpensive to implement.

Best regards.

Thanks a lot for the replies

In fact, I've been using the universal Y press-tight connector and I already tried the Restek Secure Y connector with the ferrules, but I didn't experienced a complete leak-free system. After some runs (with the temperature ramps) or when it's necessary to change the column there is always one of the column parts that becomes loose from the Y (I also tried using some resin to glue it but again not completely happy with it).

I was actually looking for alternatives...I know it exists a 2 way splitter kit from Agilent but it's way too expensive for the moment since it requires software updates. But I've been searching and I found from Gerstel the GRAPHPACK 3D/2 connectors. Is anybody using this connector from Gerstel? I would like some advice on it, please.

Regards,

Atom

If you want to splitt two columns with a "Y" connector...Agilent will do it for you free if you specify which two columns you want to split.....it's not a very well know fact...but that works....frequently done by the environmental labs...and Agilent connected columns help that out.

I use the Gerstel Graphpack system to split the GC column to a MSD and ODP (olfactory detection port) I find it is useful as I change columns regularly and it saves cleaving columns and capillaries all the time. It is fairly leak tight, just remember to tighten the fittings after thermally cycling a couple of times. And don't over tighten as you'll crush the fused silica capillaries.

Agilent is bringing out a new line of micro-fluidic splitters that are similar to the Gerstel cross piece splitters, however claim to be totally leak free - I'm yet to try them though they are on order for our new GC-MS/ODP/FPD

I'm use to work with flow spliting valve configuration. Instead of using standard Y connectors or splitter which are not leak free, I would suggest using AFP(Analytical flow products) 3 ways diaphragm valve. I have worked with this product and it allows flow spliting to different columns or detectors and the possibilities have too much potential and you can go without problem at low ppb level without leakage issue.
let me know if you need more application details. I can help.

I have used the deanswitch supplied by Agilent. It is leak-free.

we supply a programable splitter that is computer controlled. It lets you select the ratios between the 2 detectors.
www.brechbuehler.com