Trimethyl borate

[praveenpaliwal]

Hellow every body,

I want to know from u all that there is any specific column to analyze trimethyl borate on GC???
Because I have analyzed it on TC-1, the Oven was 40 degree hold for 5 minutes and then reach up to 200 degree . The injector was 130 degree and detector was 200 degree.
CArrier was N2 with 15 PSi.

I got some good result but after some time The peak shape takes long tailing and retention time was shifted from 5 to 2.0 minutes.
I changed the column and take DB-XLB with same oven programming and 200 degree injector temperature.
I got again 3.5 minutes retention time with well resolved peaks. But after few injections the retention time was reduced up to 1.9 minutes and rest of observation was same as TC-1.
Now I want to know from u all that there is another methodology to analyze TMB on GC or there is some another column which was especially design for the analysis of TMB

Best regards

Praveen

[chromatographer1]

It seems you have some components that have a poor volatility, and some polarity as well.

Perhaps another technique like TLC or HPLC might be advisable to check on such things.

best wishes,

Rod

[praveenpaliwal]

Trimethyl borate has very good volatality I have doubt on the reactivity of this it can be damage the stationary phase of column.
Any specific stationary phase is design for this???

Best regards

Praveen

[chromatographer1]

praveenpaliwal

It is not the trimethyl borate you need be concerned about. It is the impurities IN the TMB.

PEG phases are less reactive than silicone phases and carbon based phases are also fairly inert.

Do you KNOW how pure the Trimethylborate is? What impurities SHOULD there be in the TMB?

If you know it is pure, why do the GC?

I think you need to do some homework. What do you think?

best wishes,

Rod

[praveenpaliwal]

ROD ,

First listen and under stand the question. If I am not do the GC how can I ensure and release the purity of TMB.???
All the chemical manufacturer declare the purity of TMB on GC See the sigma aldrich web site.
Thebasic content is that after some injection my peak shape is not good I have lost me resolution and RT. So I have doubt that TMB may damage the stationary phase of the column. So I need the authentic literature that this column is suitable only for the analysis of TMB and this column is not suitable.
The methanol is also present in TMB because as it is a residual solvent so I have to declare the purity of TMB on GC.
So if u have some literature or authentic literature then tell me.

Best regards

Praveen

[chromatographer1]

As I used to work for Sigma Aldrich in their analytical assay group (I was the supervisor of the GC group) I am well aware that a company can state a purity by GC which may have little import to the actual purity of a chemical.

You have stated (if I understand you correctly) that your analysis originally had a good peak shape for the TMB. But the chromatography became worse and you lost retention. You suspected that the column phase was damaged. Now either an impurity is present that is causing the damage or the TMB itself is decomposing or reacting with the phases you have used. I would suspect the former but the latter is certainly possible. If TMB reacts with one silicone phase it should react with all of them.

Since TMB is very reactive with water and since you believe that methanol is present as an impurity, perhaps you should call or write Fluka and ask them how they assay TMB. They may only determine the methanol content by GC and determine complete purity by a collection of analytical techniques, such as NMR, IR, and boiling point.

If you only wish to determine how much methanol is present I would suggest that you choose a porous polymer like Porapak Q to do your analysis. While it will react with strong oxidizing or acidic chemicals it is fairly inert to most chemicals. A Carbopack B column would be another choice.

I hope someone can supply you with literature but I have not seen anything published on this reagent.

best wishes,

Rod

[Peter Apps]

ROD ,

So if u have some literature or authentic literature then tell me.

Praveen

Hi Praveen

This forum is really not the best place to be looking for literature. In the first place there are way better places on the web, such as EBSCO and Scopus, which allow powerful key word searches, and where you can see abstracts for free, and sometimes full text. Even Google throws up a surprising amount of scientific literature. In the second place, if anyone here has literature, there are copyright issues with their sharing it with all and sundry. Most of the journal publishers are remarkably liberal with their policies of allowing sharing of single copies with professional colleagues, but to expect someone you have never met to send out copies is stretching the publishers' good will a little too far.

Have yoou checked the purity of your carrier gas ? - air and water in carrier gas can destroy columns even with tractable samples, and with this particular analyte the problems would be compounded.

Peter

[praveenpaliwal]

Sir,

I have already tried on Google and lot of try I do not found any literature and suggestion about Trimethyl borate. That's why I am continuous search with this forum for some clue or idea. But unfortunately I donot found any single idea. I am totally disappointed.
I share my all problem regarding to my analysis, I was tried TC-1, DB-xlb , DB-1 but I donot get satisfied result. So I want to know that TMB is capable to analyze on GC???
I think yes because aldrich claim it on GC, they are using SPB-1 column or equivalent . I do not have SPB-1 column but I was used equivalent stationary phase and result is still wrong, that is why I want to know from all of u expert chromatographers that there is any specific column to analyze TMB??? if it is now than what is the way to analyze TMB perfectly.

Best regards

Praveen

[chromatographer1]

I suspect you may find that TMB is unstable to temperature, and will produce methanol upon decomposition.

The decomposition products may not elute from the column and may remain in the injector and on the initial length of the column, if not along the entire length of the column.

Do some research on your own and lower the injector and column temperature to below the boiling point of TMB and try injecting it on a new short piece of column to determine if you are getting injector decomposition and slowly increase the injector temperature to see if decomposition occurs and/or increases.

Good luck with your research.

Rod

[praveenpaliwal]

Sir,

Any more suggestion or Ideas regarding to analysis of TMB????


Best regards

Praveen

[chromatographer1]

Have you done any research?

What were the results?

Rod