Chromatography Forum

Hello Experts!

I am a fuel cell guy working on fuel reformation, principally reforming HCs and alcohols such as methanol, ultra-low sulfur diesel, and propane. I am frequently interested in knowing the intermediate and final product composition of said reformate.

I have an Agilent MicroGC 3000 with four columns and one inlet.

Column 1 is a molsieve 5A, 12 um film, 320 um ID, 10 m length, TCD, Carrier gas is Argon. Has a PLOT U pre-column 30um/320um/3m. I use this one only to catch Hydrogen. My current method under development runs this column so:

• injector temperature 100C
  column temperature 100C
  inject time 10ms
  run time 240s
  column pressure 30psi
  backflush 10s

Column 2 is the same, with Helium as the carrier, same pre-column, method as such:

• injector temperature 100C
  column temperature 90C
  inject time 100ms
  run time 240s
  column pressure 30psi
  backflush 10s

This is my column for oxygen, nitrogen, methane, CO.

Column 3 is a PLOTQ 10um/320um/8m, TCD, He is the carrier. His method is

• injector temperature 100C
  column temperature 50C
  inject time 100ms
  run time 240s
  column pressure 30psi
  backflush 10s

I calibrate him for CO2, ethylene and ethane.

Column 4 is my problem child. He is a new OV-1, 1.2um/150um/8m, TCD, He is the carrier. His method is:

• injector temperature 100C
  column temperature 70C
  inject time 10ms
  run time 240s
  column pressure 30psi
  backflush 10s

I intend for this one to catch (I have known certified samples of):

• 1,2-propadiene
  1,3-butadiene
  and hexane

in one set of samples,

and

• propane
  butane
  benzene
  and toluene

in the other set of samples.

I am having trouble establishing what peak is what.
Could someone give me a possible clue of what the expected elution order and times might be?

Infinitely in your debt in advance,

wave_man

I run on HP5-MS column, the orders of the 2 set of samples are exactly what you ordered. For OV-1 which is similar to HP1, the order should be the same.

I run on HP5-MS column, the orders of the 2 set of samples are exactly what you ordered. For OV-1 which is similar to HP1, the order should be the same.

Thank you kindly for your reply. I will try to post some chromatograms to show my difficulties. I think I have two many gases mixed together for an "easy" run through the calibration process. I have started from the simplest ones, with only stationary gases (is that the correct term?) so that I can see if they are influencing the OV-1 output at all. I believe nitrogen has a big change on the shape of the composite (garbage) peak of the OV-1. If folks are interested, I will post my 'grams. If it is considered rude to post pictures, i will not...

wave_man