Supporting structures for preparative chromatography columns

Abstract

The plunger used as the upper enclosure in a preparative chromatography column is suspended by one or more rods that are supported by a frame through coupling connections on the frame that can fix the position of the rod(s) relative to the frame, while the position of the rod(s) is controlled by a motorized drive system that is suspended above the column. The drive system is mounted either to the column lid or to a functional plate positioned a short distance above the column lid. These constructions allow the plunger to be raised and lowered so that the column and its parts can be exchanged, all without the need for a hoist or crane.

1 . A method for performing preparative chromatography on a mobile phase by passing said mobile phase through a packed bed, said method comprising:
 (a) placing solid or semi-solid stationary phase in a vertical preparative chromatography column comprising (i) a column tube having a removable tube cover and a removable tube base, (ii) a plunger suspended by a rod, (iii) a frame configured to detachably engage said rod, and (iv) motorized drive means mounted to said tube cover for moving said rod vertically to vary the position of said plunger within said column tube;   (b) adjusting, by use of said motorized drive means, the height of said plunger to contact said stationary phase and thereby form said stationary phase into a packed bed of a selected height; and   (c) introducing said mobile phase to said packed bed through the top of said packed bed to pass through said column tube.   
   
   
       2 . The method of  claim 1  wherein said plunger is suspended by a plurality of rods, and said motorized drive means comprise a single motor for moving all of said rods simultaneously. 
   
   
       3 . The method of  claim 2  wherein said plurality of rods are supported by a common coupling plate, and said frame is configured to detachably engage said rods through said coupling plate. 
   
   
       4 . The method of  claim 2  wherein said frame comprises a horizontal bar supported by vertical supports of extendable height. 
   
   
       5 . The method of  claim 1  wherein said rod is hollow and step (c) comprises introducing said mobile phase to said packed bed through said hollow rod. 
   
   
       6 . The method of  claim 5  wherein said plunger contains a distribution system to distribute said mobile phase across the width of said column tube. 
   
   
       7 . A method for separating a plunger from a preparative chromatography column for purposes of cleaning, exchange of the plunger or column, or replacement of a packed bed within the column, said method comprising:
 (a) supporting said column on a column support comprising:
 an upper ring and a lower ring aligned along a common axis and joined to each other by peripheral spacing means to define a column space to receive said column between said rings; 
 a plate detachably joined to said upper ring in parallel relation therewith to define a gap between said plate and said upper ring; 
 a rod movably joined to said plate along said axis, said rod passing through said plate and terminating in a plunger that extends into said column space; 
 drive means for moving said rod along said axis and thereby moving said plunger within said column space and between said column space and said gap when said plate and said upper ring are joined; and 
   (b) with said column in said column space and said upper and lower rings, said peripheral spacing means, and said column positioned within said frame, lifting, by use of said drive means, said plunger into said gap;   (c) detaching said plate from said upper ring and suspending said plate from said frame; and   (d) removing said upper and lower rings and said peripheral spacing means, with said column therein, from underneath said plunger.   
   
   
       8 . The method of  claim 7  wherein said rod is hollow and has a threaded exterior surface, and said drive means comprises a motor and gear box affixed to said plate to form a worm gear with said rod. 
   
   
       9 . The method of  claim 7  wherein said peripheral spacing means comprises a series of parallel posts joining, and distributed around the peripheries of, said upper and lower rings. 
   
   
       10 . The method of  claim 7  wherein said plunger comprises an inflatable peripheral gasket. 
   
   
       11 . The method of  claim 7  wherein said drive means defines a path of travel of said rod along said axis and said column support further comprises means for limiting said path of travel.