Syringe filter is a kind of filter connected to the front of the syringe. When the experimenters deal with the chromatographic samples with syringe filter, they should pay attention to avoiding bringing impurities in the process of filtration. One reason for the appearance of such impurities may be that the particulate matters removed from the shell material or filter membrane is going into the filtrate. Therefore, the materials of the filter membrane and shell are very important to experiments, and different types of filter membranes are suitable for different types of samples.
When handling hydrophilic samples, the experimenters should select hydrophilic membranes, which has an affinity to water and is suitable for filtrating solvents in which water is regarded as a substrate. The available filter membranes are mixed cellulose esters, etc.
When handling strong corrosive organic solvents, the experimenters generally use hydrophobic membranes, such as PTFE, polypropylene (PP) and other materials.
When the samples are referred to the protein solutions, people will choose the membranes with low protein adsorption, such as PVDF membrane.
And it is generally considered that PES membrane is more suitable for the filtration of solutions with low inorganic ions.
Besides the above factors we have mentioned, people usually consider about the volume of samples. Different volumes of samples mean choosing different sizes of syringe filters.