1. Do Labfil syringe filter contain surfactants ？

Most of the syringe filters offered by Labfil do not contain surfactants. The exceptions are syringe filters with cellulose acetate (CA) and mixed cellulose esters (MCE) membranes. CA and MCE membranes are treated with surfactants to ensure good wettability.

2. Can a syringe filter be used to prevent liquid from entering a vacuum pump ?

Yes, for water and some aqueous solutions, a hydrophobic membrane syringe filter installed in the tubing between the vacuum pump and the receiving flask can prevent accidental overflows from reaching the vacuum pump. Please note that this method will not work for low surface tension fluids, such as alcohols and solvents.

3. What syringe filters should i use for my HPLC samples ?

Because of their low inherent levels of extractables, nylon membrane syringe filters are commonly used to filter samples that are intended for HPLC analysis. Nylon membrane syringe filters may not be suitable for all samples and are ideal for near neutral pH aqueous solutions and compatible nonaqueous solvents. For samples composed of acids and bases, hydrophilic PTFE membrane syringe filters and PES membrane syringe filters may be considered. For samples composed of nonaqueous solvents that are not compatible with nylon, PTFE membrane syringe filters and polypropylene membrane syringe filters may be considered. For aqueous samples containing proteins, or similar large organic molecules of interest, syringe filters containing membranes with low inherent protein binding characteristics, such as cellulose acetate (CA), should be considered to ensure maximum recovery.