Chromatography Forum

Hellow, every body. We have one serous problem of the separation of Dibutyl phoshate (CAS NO. 107-66-4) and Tributyl Phospahte(CAS No. 126-73-8) . We have tried several columns for this like DB-1 DB-WAX, DB-1701 and DB-624 but both are co-eluted .
We want them separate so which GC stationary phase is suitable for it?
Either any derivatization technique is suitable for the separation

Praveen

Are the two peaks the same size? Do you know the compounds are pure?

DBP should be very difficult, and TBP as well. Poropak P might be a solution but I have doubts.

Carbopack C with a 1% coating of FFAP?

Chromosil 310?

But the issue remains, how will you get the DBP through the detector ?

Rodney George

SIr,

We have standard of Aldrich of both samples. OUr R&D expert also confirm that there is possibility of TRibutyl in Dibutyl also.
Now can u suggest us some literature or web site for the separation of these two's

Praveen

My suggestion is to ask Aldrich to tell you the tests they use to determine purity.

I doubt that they use gas chromatography to determine purity, unless it is to revert the DBP and TBP back into the phosphoric acid and alcohol to determine the n-butanol and homolog alcohol content as one might do to determine the fatty content of a triglyceride, for example.

Please let us know if you find any literature on this subject. I would enjoy reviewing it. I would have many questions to propose.

good luck and best wishes,

Rodney George

Sir,

I aasked aldrich for the same but they declared titrimetric purity not GC. I also asked them to tell us GC method if possible.
I am also trying to consult the literature and other technical person but I request u to keep in contect.

Praveen

Praveen,

Having worked for Sigma-Aldrich, I will state this much:

If there were a method to determine purity by GC it is quite likely they would employ it.

Since they don't have a method to share with you, I suspect the DBP is too difficult an analyte for GC analysis.

I would also expect that NMR analysis would also be indicative of purity, as well as the titration they mentioned.

Good luck,

Rodney George

http://www.cdc.gov/niosh/docs/2003-154/pdfs/5017.pdf

Found a CDC paper where it seems they derivatize dibutyl and tributyl phosphate with BSTFA and inject on a "1.2 m x 6-mm OD; 3% OV-101 on 100/120 mesh Chromosorb WHP" packed column and detect via a "phosphorus FPD".

Hope that helps.

Sir,

This is NIOSH MOA and we also have it, how we can derrivatized it it is not mention in this note.
CAN u tell us briefly, about derivatization.

IIndly in the monitoring sample this derivatization process is work or not?

Praveen