Chromatography Forum

Hi! I've posted questions a few times about the practicalities of building a GC from scratch so I thought some of you might be interested in seeing the preliminary outcome, and I've made a video on it.




Hope you enjoy,

Thanks,

Chris

Impressive!

If the large peak is butane + propane, what could the peak between this and the unretained (air) peak be? Is this a separation between oxygen and nitrogen or would that be impossible in the current setup?

Thank you so much!

I'm fairly certain there's almost no separation between nitrogen and oxygen, although I think under certain conditions I've seen a sorta lumpy peak from just injecting air indicating that the peak contains multiple components.

air and CO2 are close to baseline separated on this column as well.

--Chris

So now you can test with this machine (in this conditions and with this column) if the calories (Wobbe number - MJoule per m^3) your gas company sells to you is worth money they got from you.

Haha yeah that is true, although maybe a bit boring.

I'm currently prototyping a corona discharge ionization detector, i'm also working on a FID, and using micro-packed columns. I'm trying to replicate some articles I found on preparing super-megabore PLOT columns from commercial 1/16" steel tubing!

Thanks for the interest!

Typically FID polarization voltage is volts to hundreds of volts.

How do you plan collecting pA to mA ion current nearby the corona discharge ~10-20kV AC.

Btw more interesting and more universal detector http://www.ldetek.com/our-products/plasmadetek/

Covers both FID, HID, TCD, PFD and many other detectors in single machine.

I.e. you can see with this RF generator signal simultaneously from He2, N2 and hydrocarbon compounds.

It's not as small currents as you would think, in the paper on it (it's fairly new) they just have the collector electrode grounded via a 10 mega ohm resistor, giving a voltage output in 10s of milivolts.

I have a cocroft -Walton multiplier generating around 8 kv, as they used in the paper.

Wow that detector is nice!! Perfect for experimentation too. Likely a bit over budget though, but maybe they've published some litterature on it. Thanks for the hint!