Do you know which filter should be used for the removal of traces from an alcoholic solution?

A 0.2 micrometer filter will have to be chosen. The filter material must be compatible with the alcohol. For 70% ethanol, cellulose acetate and nylon are less suitable. Well compatible are polypropylene, Polysulfone, PTFE and Polyvylidene fluoride (PVDF). For 96% ethanol, almost all the materials mentioned are suitable.