Rtx-XLB vs. DB-XLB capillary columns

[djletin]

I am working on an application looking at PAH-type hydrocarbons in seawater at ultra-trace concentrations (0.1-10 ppb). I have about 40 compounds to deal with and am planning on using direct immerseion SPME coupled directly to Agilent GC-MSD. I have decided a 25m x 0.2mm id column with 0.33u df is best option. Any expirecince with either/both Rtx-XLB (Restek) or DB-XLB (Agilent/J&W) phases?

[AICMM]

djletin,

How hot do you intend to go? You might consider using a SimDis column instead, depending on your application. I can post a part number for one if you need me to.

Best regards.

[AICMM]

djletin,

You might also consider the RT-PAH or Rxi-5Sil columns. On Restek's web page is an app note for low level PAH's by MS/
SIM.

Best regards.