sodium tetraethyl borate

[Sassolini]

I have a problem. When I try to analyze TriButylTin (TBT ) in GC-MS in different matrix I need to use derivatization with SodiumTetraEthylBorate (STEB) I have several problems.
Even if the solid STEB is open, few minutes before use, it never dissolve easily and I have always a cloudy solution difficult to dose with pipette. Last time I try to use THF (a high purity THF is needed?) but also in that case I obtain a cloudy solution and problem in blank!
Someone can give some tips and can recommend some product? Especially for solution conservation and handling.
I read several paper and methods but I think that something is missing in instruction given…
Thanks a lot for any help you give

[HPLC chemist]

Why are you trying to derivatize TBT? Use the same extraction procedure for Tinostat (TBT) in the AOAC section for animal feed and use SIM (simple ion mode) to detect Tin (Sn). Normally TBT is quantified by ICP or AAS (your using a shotgun to kill a fly!).

[jerole]

Hi,

You have to dissolve the NaBEt4 in a 0.1M NaOH. Usually you prepare it at 2% w/v, you dissolve 1 g of NaBEt4 in 50 ml of 0.1 M NaOH.

This derivatization agent is not very stable, so what I do is to distribute the 50 ml among several small vials and freeze them. Each time I need some NaBEt4 I take a vial and unfreeze it.

The derivatization conditions are also very important. This reagent if for derivatizations in aqueaous phase and if you don't adjust the pH correctly it won't work. Your sample has to have a pH between 4.5 and 5. If you don't see any peaks, 99% of the time it is because your derivatization failed.

Also, avoid using plastic material to reduce your blanks. Many plastic materials use organotin compounds as stabilizers. Prepare everything in glassware.