I need to find a method to analyse the clearance of sodium cyanoborohydride throughout a process.. We believe it has been cleared but we are strugglinf to find an assay that will show this with high sensitivity. Does anyone have any suggestions on what could be used?

The old-school method is to use iodometric titration.

 

http://pubs.acs.org/doi/abs/10.1021/ac60071a041?journalCode=ancham&quickLinkVolume=24&quickLinkPage=1843&volume=24

 

This is for NaBH4, but it can be used for the cyano version as well although the stoichiometry is different.

 

Otherwise, I would hydrolyze in highly acidic solution and use various cyanide assays which are available.

I have been researching various cyanide kits available but was hoping there might be a kit that allows accurate quanititation of the sodium cyanoborohydride. I'm not sure how well the iodide titration method is at quantifying sodium cyanoborohydride compared to sodium borohydride?

 

Ideally I would like to be able to show that the cyanide and the boron are cleared during the process is there any suggestions on a more up to date sodium cyanoborohydride method or cyanide detection method the has high sensitivity?

 

 

The reaction with iodine might not have a nice well defined stoichiometry, but it should work.

If all you want to know is " do we still have cyanoborohydride present in this stuff" and the stuff doesn't destroy iodine then the answer is no.

You can see the colour of iodine in the presence of starch with very small quantities, so you can see the effect of very small amounts of reducing agents too.

The big problem would be deciding if you still have cyanide, borohydride, cyanoborohydride, or some mixture.

 

The other problem would be what else is present and does it mess things up?

Thanks for the reply.

 

That is my worry as well that there maybe interference with other components. Would you suggest it simpler to hydrolyze the sodium cyanoborohydride and test for the seperate components?