Working with PVP and and antioxidants, the peroxides in PVP are killing my antioxidant, can you suggest a way to remove the peroxides from PVP-MeOH solutions?
Try a polymer supported NaBH4 (eg. 359947 Aldrich) in water or MeOH. But, because it contains tetramethylammonium counterion some stirring with an activated strong H+ resin might be necessary before removing the PS-borohydride resin. Then the solution can be freeze- or spray-dried (aq. solution only).
When you have difficulties with filtration, dilute the reaction mixture as you wish and allow to sediment the solids and remove the supernatant and then get your solid by evaporation or freeze-/spray-drying, according your solvent.
Please, note that the activated ion-exchanger should be washed with water and methanol before use - washing of the PS-BH4 before use is a matter of question, but if you need to wash it then use water only..
Have you tried flushing it through a column full of activated alumina? I know that this usually removes the peroxides, but you may need to pass it through a very, very fine filter after to remove suspended alumina. Iron (II) sulfate is also effective at peroxide removal, and its solubility in alcohol is negligible.
Thank you for your answer Dean, we will try this as well. Actually just adding Tetraborate seems to help quite a bit. I can try the Iron (II) and maybe it will work too. We keep Alumina in all our THF and other organic solvents all the time.
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