Chromatographic column with improved end fittings

Claim 1

In a packed column adapted for use in liquid chromatography, said column comprising a tubular section, and end-fitting assemblies at the inlet and outlet of said tubular section and said end fittings at the inlet of said column comprise: (a) a first threaded connector member said first connector is permanently attached to an end of said tubing, (b) a second, complementary, threaded fitting member, adapted for attachment to said tubing and forming, with said first connector member, a chamber in which to house parts wetted by any said process liquid passing through said column, (c) said process-wetted parts forming a conduit between the end of said column and the adjacent end of said column, the improvement wherein said conduit comprises substantially no liquid dead space and said process-wetted parts are supported on said permanently attached connector and comprise, at least, (1) a filter insert assembly, adapted for compression between said connector members and comprising, at the end of said filter insert assembly which is most remote from said tube, a bearing surface adapted to receive and form a metal-to-metal seal with a liquid feed tube and, at the end of said insert assembly nearest said tube, a micro-filter (2) and a retainer plate comprising a central passage formed of a large number of minute holes and also having means to engage the internal wall of a said exterior connector member; (d) and wherein said filter insert assembly is readily removable from said housing without disturbing said packed column.