Low Level SIM and PAH's

[sllimbri]

Does anyone run PAH by SIM on an Agilent 5972 w/5890GC? If so, what is your calibration range? What column are you using? I would like to be able to calibrate down to 0.05ug/ml. Is this possible on a 5972?
Thanks.

[Schmitty]

In my experience a 72 is not any less sensitive than a 73. I have done PAHs on a 73, taking conditions/column from a Supelco/Restek catalog. It was a few years ago that I worked on it, but I think I recall my low standard was 1 or 3 µg/mL in DCM. I was using one quant ion and two qual ions, I believe.

[sllimbri]

1.0ug/ml is not low enough. Is it possible to calibrate lower and how is it done?

Thanks

[Schmitty]

Haha, sorry...wrong units. I was at 0.001 or 0.003 µg/mL for a low level standard.


edit: I reread your question, and you ask "how" to calibrate the instrument. Have you used a GC or GC/MS before? If you have, then the PAHs are the same as any other compound, with their own quirks. If you have not used a GC, then you have much more to learn.

I had no special technique for my analysis, that I recall. I know clean solvents were a must, since I did signicicant concentration of my extraction solvent (toluene).

[sllimbri]

By "How" I mean method parameters. Yes...I maintain four gc/ms's daily for the last 6 years.

Thanks

[Schmitty]

Well, for method parameters, I would work from those in a catalog. I like Supelco, and they have 10-12 good examples in the current (2007-2008) catalog. Page 345 is a great example of the 525.5 EPA method.

It has the GC conditions listed, and they are all fairly nominal. High injection port temp, low oven starting temp, ramping to 330C, DB-5 column. Other than that, I don't know what to say...it's all pretty basic, nothing special.

Good luck