Thanks a lot for the very helpful answers!
@Wolfram: I will look into the PorabondQ’s. The hint with the smaller diameter was very helpful. Agilent is offering a PoraPLOT Q with 0.25mm and 25m length, and seemingly also offers longer columns if needed. So far, I only worked with 0.32 ID columns. Is there anything that is changing drastically and that I should keep in mind when switching to a smaller ID, analytical-wise? I guess the sample volumes have to be smaller?
By the way, I usually inject manually 50 to 300 ul gas that contains around 1% CH4-CO2-CO mix diluted in He. The gas compounds vary strongly in concentration.
@Herb: Thanks, I look into the GS-GasPro!
@Klaus & Robert: The Carboxen1010 column sounds indeed very interesting! Almost too good to be true. Probably very much worth a try! Robert you mentioned the CO2-sorbtion problem, something I was quite afraid of when I saw that this column is operated at quite high temperatures. However, Klaus wrote me that he has good experiences with the column in separating CO2 and CH4. I definitely keep the Column in mind!
All the best,
we use a Supelco / Sigma Aldrich Carboxen 1010 PLOT column (0.32 ID, 30 m) for separation of permanent gases, such as O2, N2, CH4, CO2. It would also separate CO and the retention time is clearly deviating from the timing of N2. The column also separates O2 and N2 if operated at 30 °C
Am 05.01.2017 um 12:38 schrieb Herbert Tobias:
Just to put out an unconventional choice of column to try is the GS-GasPro (Agilent). I do not know how it would handle large amounts of CO and N2, etc... but I have used it for excellent separations of CO and C2H6, CO2, and other natural gas products from pyrolyotic processes.
On Jan 5, 2017 5:38 AM, "Küter Nico" <[log in to unmask]> wrote:
We are curious about an efficient way for separating N2 from CO in a GC to analyze CO for d13C and concentration.
We are already able to separate the species somewhat sufficient with 1) an Agilent 30m GC Carbonplot (0.32mm widebore, 1.5um film) by pushing it far below its lower temperature-limit (-70°C) and 2) quite well with an Agilent 50m PoraplotQ (0.32mm widebore, 10um film, also at -70°C). We use a HP 6890 GC that is coupled to a Delta V IRMS.
The important point is that we also need to analyze coexisting CO2, CH4 and C2H6. So these should not get lost during the separation process.
Again, the Poraplot Q does a good job, but we are curious if anyone in this community has experience with other columns or with the N2-CO separation in a GC in general.
Thanks a lot and best wishes for the New Year!
Institute for Geochemistry and Petrology
-- Dr. Klaus-Holger Knorr Dipl. Geoecology Univ. Institute for Landscape Ecology Ecohydrology and Biogeochemistry Group Heisenbergstr. 2 University of Münster 48149 Münster Germany Mail: [log in to unmask] Phone: +49-251-83-30207