Hi,

The best option is to use NaOH to neutralize and adjust the pH. HCl will harm the metallic components and damage the vacuum pump.

Hope this is helpful to you!

Hello Abderrahim Alahyane ,

thank you for your answer, but unfortunately the hydrolysate will be used for cell cultivation, where no salt should be present. Since neutralization with NaOH results in a vast amount of NaCl, I was thinking that the most efficient way of desalting is to firstly get rid of HCl in vacuo, resuspend the hydrolysate in water, pass it through catex (salts and amino acids stay in the column), elute the amino acids/hydrolysate with NH4OH and then get rid of residual NH4OH from eluate in vacuo as well. |I couldn't think of any better way to efficiently desalt the hydrolysate, although I am well aware HCl vapors can damage any component (mainly the pump) in the oven.

Can you think of any option for recovering of salt-free hydrolysate after acidic hydrolysis with 6M HCl?

You can use the desalting column, available from Clinisciences. 6564-25 | EZ-Desalt™ Spin Desalting Columns Clinisciences

Furthermore, if you would like something much cheaper and faster, you can try dialysis, simply select a dialysis membrane (porosity), through which only the salt particles permeate.

I'll look into the column, thank your suggestion! :)

I believe amino acids are similarly small just like NaCl, so dialysis probably wouldn't work here. Electrodialysis could be alternatively implemented, but not with 100% recovery.

You need to pay attention to the size of your peptide, the porosity has to be chosen with precision, I hope I've helped you.

I think this is possible because the acid Hcl evaporates easily

you van check

https://www.technologynetworks.com/drug-discovery/product-news/safe-evaporation-of-solutions-containing-hydrochloric-acid-286553

also check

file:///C:/Users/Dr.Karima/Documents/kReactions%20involving%20HCl%20and%20their%20Evaporation.pdf

It depends on how much HCl you'll need to evaporate.

Part of the reason you use a rotary evaporator instead of a vacuum oven or other vacuum dryer is that in a rotary evaporator setup, the HCl liquid and vapors only come in contact with glass, which is highly chemically resistant. In contrast, large volumes of HCl will potentially create enough vapors to corrode the inside of the vacuum oven, especially over time and especially if your vacuum pump has a relatively slow evacuation rate.

If you do attempt this, you'll need to be very certain to use a condenser or a cold trap (like this one: https://rotovaps.net/products/ai-t40-cold-trap-for-safe-vacuum-operations) between the vacuum evaporator and the vacuum pump. While very small quantities of inert vapors might not be too harmful for some vacuum pumps, any HCl will rapidly damage most pumps.

That said, I would still strongly recommend the standard practice of performing the initial and bulk of the drying with a rotary evaporator and only using a vacuum oven for finishing the drying process, if necessary.

Should anyone need a vacuum oven: https://labovens.net/collections/vacuum-ovens