Glass vacuum chromatographic apparatus with filter disc porosity 0 compound : a vacuum flask 1 L rode 29/32 screwsocket a chomatographic column 29/32 screwsocket with sinter porosity 0 a dropping funnel with stopcock PTFE key 29/32 screwsocket 2 caps andseals 29/32 screwsocket borosilicate 3.3