Chromatography Forum

Hello!
Can I find syringe filters or better precolumn filter to filter out polymers, or only centrifugation with "centricon", "minicon" can be used?

Thank you

Marina

What kind of polymers? What are the details of the method?
If they remain soluble you maybe be able to wash them out of the column and not have to remove them.

Dear Marina; the kind of polimer that you have to remove is very important, alsdo the method you are usisng; but remember that the main precolumn porpous is to retain contaminent that are strongly retained in the column. physical filtration is only for phisical remotion.

cheers.

Oscar

Thank you for the answers!
The polymers are methacrylic acids- methacrylate, poloxamer and other pharmaceutical excipients. The quantity is about 1g dissolved in 25 ml of high organic and then precipitate by dilution with water (I can not acidify too much). The mobile is 90% ammonium acetate (pH=7) in Ethanol and gradient to 40% ethanol, the composition of the sample after precipitation is 10% water in ethanol. The number of plates drastically drops after about 10 injections. Washing with high organic (as was used to dissolve the polymers in the first place) did not help. I thought there may be filters for molecular weight cutoffs as those used for the centrifugal devices (centricones, minicones, nanosep) or any other suggestions?

Thank you

What is wrong with centrifuge ultra-filter devices if your polymer is big enough and your analyte is small enough? There is a reason for the centrifugation: The necessary pressure to force the small molecules through. Gilson used to (maybe still does?) make an apparatus to ultra-filter in line with columns.

Thank you for the answer! It is just time consuming with a lot of samples, but I probably have no choice. I will look up Gilson!