PAH on Varian Saturn 2200 w/ 1177 injector

[Spadey]

Hi

Is anyone running PAH analyses on a Varian Saturn 2200 (Sil-chrom trap) with a 1177 injector?

I've been trying to set this up for ages with no luck - basically I see everything up to MW 202 and then it tales off to nothing.

I've tried several different columns, so am guessing it's either the injector setup or the trap.

Any help would be great as my head is getting sore from banging it against the wall...

[Peter Apps]

And your analytical conditions are ..... ???????

[Spadey]

Which ones!!

I have tried all combinations I can think of...

Samples are in CS2.

Column program is generally 60°C 1 min hold ramp to 320°C (ramp rate 5 or 10°C/min) hold 5 - 10 mins. Column flow 0.8 mL/min constant flow.

Tried hot trap (220°C), medium trap (180°C) cool trap (150°C)

Tried hot injector (350°C), medium injector (300°C), cool injector (270°C).

Varied injection volumes (1 - 3µL) and liner (2mm vs 4mm ID, with/without glass wool packing).

Varied injection speed (10 - 50 µL/sec).

Varied injection style (split, splitless, spilt/splitless) with varying split ratios.

Also tried regular 30m 0.25mm/0.25µm column and equivalent fast-GC column (both BP5 phase equivalents)

All to no avail...hence the sore head!

What I'd like to know first off is if anyone has successfully run PAH on this set up...

[Spadey]

Which ones!!

I have tried all combinations I can think of...

Samples are in CS2.

Column program is generally 60°C 1 min hold ramp to 320°C (ramp rate 5 or 10°C/min) hold 5 - 10 mins. Column flow 0.8 mL/min constant flow.

Tried hot trap (220°C), medium trap (180°C) cool trap (150°C)

Tried hot injector (350°C), medium injector (300°C), cool injector (270°C).

Varied injection volumes (1 - 3µL) and liner (2mm vs 4mm ID, with/without glass wool packing).

Varied injection speed (10 - 50 µL/sec).

Varied injection style (split, splitless, spilt/splitless) with varying split ratios.

Also tried regular 30m 0.25mm/0.25µm column and equivalent fast-GC column (both BP5 phase equivalents)

All to no avail...hence the sore head!

What I'd like to know first off is if anyone has successfully run PAH on this set up...

[Spadey]

Which ones!!

I have tried all combinations I can think of...

Samples are in CS2.

Column program is generally 60°C 1 min hold ramp to 320°C (ramp rate 5 or 10°C/min) hold 5 - 10 mins. Column flow 0.8 mL/min constant flow.

Tried hot trap (220°C), medium trap (180°C) cool trap (150°C)

Tried hot injector (350°C), medium injector (300°C), cool injector (270°C).

Varied injection volumes (1 - 3µL) and liner (2mm vs 4mm ID, with/without glass wool packing).

Varied injection speed (10 - 50 µL/sec).

Varied injection style (split, splitless, spilt/splitless) with varying split ratios.

Also tried regular 30m 0.25mm/0.25µm column and equivalent fast-GC column (both BP5 phase equivalents)

All to no avail...hence the sore head!

What I'd like to know first off is if anyone has successfully run PAH on this set up...

[Peter Apps]

The one thing that looks odd (depending on the column i.d which you do not specify, except that 0.25 mm was an alternative) is the flow rate of 0.8 ml/min. This is low, and also seems to be the only thing that you have not changed. Apart from very long retention times this might give problems getting the compounds out of the inlet, and with the pressure in the ion trap, which needs some helium around to damp the ion vibrations. Check out the flow vs psi thread on the GC page.

Peter

[AICMM]

Spadey,

Did you get this from an application note or publication? Is this available? I am assuming the Silchrom trap is between the inlet and analytical column?

If you have a drawing or app note, that would help immensly.

Best regards.

[akthmps]

FYI: The silchrom trap is the mass spectrometer analyzer. It's an ion trap.

I would try a higher flow rate. The Saturn ion trap is optimal with helium flows from 0.75 to 1.50 mL/min. Higher/lower flows can be attempted, but for sure you would need to run an FC-43 autotune at the given flow.

I would try running from 1.2 to 1.5 mL/min, making sure to run an autotune with the new flow rate.

Good luck.

-Aaron

[akthmps]

FYI: The silchrom trap is the mass spectrometer analyzer. It's an ion trap.

I would try a higher flow rate. The Saturn ion trap is optimal with helium flows from 0.75 to 1.50 mL/min. Higher/lower flows can be attempted, but for sure you would need to run an FC-43 autotune at the given flow.

I would try running from 1.2 to 1.5 mL/min, making sure to run an autotune with the new flow rate.

Good luck.

-Aaron