Chromatography Forum

I am considering making a check standard applicable to both FID and TCD detectors. The check standard from Agilent is only a hydrocarbon mix. This mix does not give me an indication if there are acidic or basic active sites in the system. A simple 3 component check standard using readily available chemicals is ideal. One component being somewhat organically acidic, one organically basic, and one neutral hydrocarbon all in a simple solvent which hopefully elutes at the beginning of a run. I am wanting to generate a baseline chromatogram and be able to see acidic or basic contamination via the test mix. I presume tailing on one or all peaks could indicate active sites. Does anyone know of such a mixture which can either be purchased or easily made?

Since I look after NPDs and ECDs in addition to FIDs, TCDs, and MSs, my all-purpose test mix is:

Pyridine
Bromobenzene
Toluene

That gives a good, measurable signal in all detector types, and there's enough discrepancy in both BP and polarity that it separates well regardless of column chemistry.

It's been a while since I made any up, but IIRC I dissolved it in methanol.

You could throw in benzoic acid also to have something acidic, although based on BP it's going to elute a fair bit later than the others.

Phenol may work for the acidic component.

Don't know why I didn't think of phenol-it should elute sooner than the benzoic acid I suggested.

Also, just checked my last batch of test mix, and apparently I used P-Xylene rather than toluene.

Such mixtures are still available commercially, like https://www.sigmaaldrich.com/catalog/pr ... &region=US

Lists
2,6-Dimethylaniline
2,6-Dimethylphenol
Eicosane
Heptadecane
Hexadecane
Octadecane
1-Octanol
2-Octanone
Pentadecane