Chromatography Forum

Hi All,
Does anyone use this with the built-in Tenax trap?
What analysis do you use it for?
Is the trap easily replaced/recharged?
How robust is it?
Is it a good reproducible alternative to automated SPME?
Thanks in advance
WK

Hi !
I'm using PE-Turbomatrix with Trap since november last year. I built some methods in order to analyse Vinylchloride (VC) and some Acrylates (Methylacrylate, Methylmethacrylate) in Polymeres (monomeres!).
My experience is, that the trap is easy to use and you can reach very low limits of detection (e.g. for VC I'm able to determine down to 10 ppb VC in PVC).
You are able to load the trap up to five times, and then you will get about 95 % of the analyte out of the sample. After the multiple loading of the trap the whole amount of trapped analyte can be brought onto the column (here also a split-injection is possible; the split-vent is under the built-in trap.)
The trap is robust and easy to change, although the tool in order to change the trap is a little bit primitive. But it works.
The reproducibility is excellent.

You can look at the following web-site: www.sisweb.com/index/referenc/resins.htm
There you can find a listing of the various traps (trap materials) and applications.

Regards

Thanks GC Man,
Did you perform the analysis before using SPME?
I suppose I am looking for a reproducible alternative to SPME (for analysing volatile flavour components in beverages)
And a technique that is nicely automated.
Does it have to use PE vials and special caps?
Can you quantify the %RSD?
Can the trap be exposed to the headspace for the entire vial equilibration time or just for a minute or so in loading sample?
Sorry for so many questions!!
WK

Hi again !

You don't have to say sorry for your questions. That's the reason why we are in the forum.

No, I didn't perform the mentioned analyses by SPME before, I used MHE-technique. I never used SPME for quantitative analyses, only for qualitative analyses in combination with MS !
I think that method developement with the trap is very easy; you certainly have to use PE-vials (about 23ml volume) ; you can use all caps that fit to your analyse (no peaks from the cap in the region of your analyte-peaks).

When I mentioned the excellent reproducibility I meant: I performed the determination of VC in a PVC-granulate with 10 GC-runs; the %RSD was less than 2 % !!! (I never had such a low deviation in my laboratory);

You can't expose the trap to the HS for the entire equilibration time; while equilibrating the vial, only pure carrier gas is flowing through the trap.
After equilibration, the sample will be loaded on the trap ("first loading cycle"). Then pressurization of the vial takes place again and the sample will again be loaded on the trap ("second loading cycle"), ...
You can determine the number of loading cycles and the loading time (as it is standardly by PE: injection time !)
After the last loading of the trap, the trap will be heated rapidly (you can determine this temperature) and the whole trapped sample will go onto the column (here you also can vary some settings as mentioned above, e.g. split, split flow)

I think it is a good equipment for determining low levels of volatile compounds, especially in solid samples.

If you have further questions, just ask !
Sorry for my english, but I'm not from GB as you can see !

Thanks again for your time GC Man,
Don't ask me to reply in German!
Your English is superb!
I will approach PE soon for a demo for my samples
WK