Hi Foroogh, I believe that does not exist a standard method for the MWCO quantification.

Dear Mario,

Thanks for your reply. To be honest I know this. But I need to know what is the UF membrane companies protocol for MWCO determination. I probe to find it.

Regards

Unfortunately, because there is no industry standard method, users should always perform a "process relevant" test to characterize the performance of any candidate membrane. For any critical process, testing across multiple lots would be wise. The fact is that the separation performance on UF rated membranes will vary across a wide range of test attributes- concentration, cross flow, TMP, temperature, as well as the solvent makeup. The ASTM method using a mixed dextran model does define most of these criteria and helps to characterize the full range of separation performance. From my observations across many suppliers, the NMWCO is often designated as the MW where the membrane provides a 90% retention-often designated as R90-using one of the typical model polymers. The industry advice for valuable processes is to select a membrane that is 3-5X tighter than the size of the target molecule to ensure adequate retention.

Dear Craig,

Thank you so much for your help and time. Could you give the patent or paper consists of "The ASTM method using a mixed dextran model" please ?

Regards

Hi Foroogh, The revised test method is attached as well as a more recent publication by GE adapting the basic method for characterization of an open UF membrane in the hollow fiber format. The references at the end may serve your needs for additional ideas.