Please look at the following below links which may help you in your analysis:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2911528/pdf/216_2010_Article_3532.pdf

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3196601/pdf/nihms286930.pdf

Thanks

Have u thought of using a hood.

May be u can use HCl to lower the pH which will decompose the sodium cyanoborohydride.

Rayan Murtada Sodium cyanoborohydride NaCNBH3 is a reducing agent which is commonly used in Reductive Amination (cyclic amidation/C-N bond formation/ring closure). This kind of reaction should be carried out in fume hood. In reductive amination reactions, after treatment is very important. After completion of reaction you can try adding 0.1M aq. HCl solution to the mixture (at 0 C). Extractions can be made by adding mixture of saturated NaHCO3 : Ethyl Acetate (1:1). Wash the extracted organic layer with brine followed by H2O and dried over Na2SO4.

How big is the difference between the molecular mass of NaCNBH3 and your conjugate? If it is large enough, then gel filtration (for example with disposable desalting columns like NAP5, https://www.fishersci.de/shop/products/illustra-nap-columns-nap-5/p-6858008) or ultrafiltration (centrifugal cells like https://www.vivaproducts.com/vivaspin-centrifugal-concentrators/vivaspin-500.html) are simple methods that will not damage your conjugate.

If your conjugate is too small to be separated by these methods, and there are no methods to bind the conjugate(IEC, C18,...), then you have to chemically destroy the borohydride, taking care not to damage the conjugate. Others have suggested methods for that.

you may be able to use HCl to lower the pH which will decompose the sodium cyanoborohydride.

and also u can separate by using gel filtration . take a look to this link https://www.fishersci.de/shop/products/illustra-nap-columns-nap-5/p-6858008)

After multiple experiments, I have determined acetone precipitation solved this issue.

Source:

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