Chromatography Forum

Get an old GowMac 350 Thermal Conductivity Detector like the one demonstrated as follows. They are strong and basic.

I lifted dig up on Ebay for $400. Everything worked (well, it required another segment yet that is normal - see beneath).

Get an old strip diagram recorder - perhaps $75. It ought to have the capacity to complete 0-10 mV full scale (ideally 0-1mV). Even better, you can spend another 300 or something like that and get the Peak Simple advanced interface and connect it to a PC. Programming is free.

You may need to introduce or supplant the segment (I needed to). Get a 1/8" x 6 ft Carbowax 20M (20%) on chromosorb P or comparable (Restek or GowMAc, $150 - 300). Put new septa in the infusion ports if necessary, about 5$ each or less. You will require 1, 5, or 10 microliter GC syringes (about $25 on Ebay) to infuse your examples

You can keep running with nitrogen N2 or helium He as the bearer gas. N2 is less expensive yet less delicate - anyway for refined spirits affectability isn't an issue.

Great partition and exact assurance of methanol and ethanol.

Nice job! I've always wondered if getting cheap ebay GC's up and running.
I wouldn't bother with the pen plotters though. They're not really worth it today, and finding spare pens and paper for them is a nightmare. Any decent microcontroller can be made to read an analog voltage and then transmit it to a file via serial.

I've recently completed my first prototype of a completely diy gc, using an arduino to transmit data directly to excel. Exporting that data as an .xy text file let's any of the free gc analysis software read and integrate it. Works a charm!

Here's some info if you're interested:
http://www.eevblog.com/forum/projects/gas-chromatograph-diy-done!/

--Chris

http://unichrom.com/simple/simplee.shtml

As soon you get it up and running (demo version allows 3 min of instrument acquisition time), write us and we can give you PC-bound license for free.