DIY gas chromatograph - video

[ChristofferBR]

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

[Rndirk]

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?

[ChristofferBR]

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

[antonk]

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.

[ChristofferBR]

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!

[antonk]

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.

[ChristofferBR]

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!