Glass vacuum chromatographic apparatus with filter disc porosity 4 compound : a vacuum flask 500 ml rode 24/29 screwsocket a chomatographic column 24/29 screwsocket with sinter porosity 4 a dropping funnel with stopcock PTFE key 24/29 screwsocket 2 capsand seals 24/29 screwsocket borosilicate 3.3