Multiple ISTDs

[orcicdejan]

Hello!

I'm using Agilent's GC-MS 5973N+6890N and ChemStation DataAnalysis G1701DA ver D.00.00.38.

We want to use 3 internal standards (deuterated PAHs) for the analysis of PAHs. My question is, how to tell ChemStation which ISTD to use for which compound?

Thanks!

[Consumer Products Guy]

There's probably a more straightforward way, but you could always make two additional methods from the first, each detailing use of a different internal standard, then "reprocess only" using the second and third methods as well.

[jaj]

There is a more straightforward way. The 1st internal standard is listed first in your method followed by the compounds associated with it. Then list the second internal standard followed by those associated compounds
and so on.

The internal standard is designated on page 2 where it says compound type use I for internal standard; T for target; etc.

You will notice in your sample list that the target compounds are in order by retention time, but the internals since they have to first are not.

I hope this helps you.

[orcicdejan]

Wait a minute! You're saying that it's enough to make compound list like:

* ISTD1
cmpnd 1
cmpnd 2
cmpnd 3
* ISTD 2
cmpnd 4
cmpnd 5

and ChemStation will know that ISTD 1 is for cmpnds 1-3 and ISTD 2 for 4 and 5?

[jaj]

Exactly!

On page 1 where it says Quant Type choose ISTD ot Target
and on Page 2 choose Compound Type I for internal and T for target, etc.

If you click on the Help Key it will explain or show you how to set it up.

Have a good day!