Internal standard for VOCs analysis with P&T GC-MS

[bsxenia]

Hello everyone,

I would like to add an internal standard to my system for the determination of VOCs (VC, cis-DCE, TCE, PCE)in water that it is not volatile but still has the properties of my compounds.

The column that I am using is a RT-QSPLOT 30mx0.32mmx10um and the absorbent of the trap is TENAX.

Lately, we had some probles of the sensitivity and the problem came from the MS, so I would like to add an internal std to control my system and I think that the best solution would be a similar compound but at the same time not so similar, not volatile.

Is anyone that could give me an advice?

If not, I think I will add a internal std in a gas phase directly to the P&T.

Thanks a lot.

Greetings,

bsxenia

[AICMM]

bsxenia,

Bromofluorobenzene is the first thing that comes to mind. Heavy, halogenated, but volatile enough.

Since you are using MS why don't you just use something deuterated like 1,1,1-TCA?

Best regards.

[bsxenia]

Thank you very much for your answer!

It's a good idea.

[Bigbear]

Sounds to me as if it could be water quenching ionization in the ms. Using an IS will help but, it's only a band aid fix.

I use fluorobenzene as my IS , and BFB and 1,2- dichlorobenzene d-4 as surrogates.

See other posts about method 524.