Test Procedure for Removing Polystyrene Latex Microspheres from Membrane Filters

Abstract : A test procedure was developed for removing 1 micrometer polystyrene latex (PSL) microspheres from membrane filters. The procedure consisted of placing the filter, with the collected PSL microspheres, in a test tube with water and glass beads. The text tube was held on a padded shaker table to induce vortexing for 50 sec and then was shaken by hand for 10 sec. Vortexing and hand shaking were repeated many times, and samples were taken after predetermined times of shaking. The samples were analyzed using a fluorometer. From the results, a total shake time of 5 min (50 sec vortexing and 10 sec hand shaking repeated five times) was adapted as our shaking procedure for removing the PSL microspheres from the membrane filters. No significant differences in the recovery were found when the procedure was followed by two test operators.