Method of chromatography on a porous packing material produced by a drawing process

Abstract

The invention relates to a method of chromatography wherein a gaseous, liquid or supercritical fluid mobile phase, which contains substances to be separated, flows through a porous packing which comprises a plurality of capillary channels which extend in the direction of flow of said mobile phase, said packing being manufactured by a method wherein: a bundle of elementary fibres is assembled, said fibres comprising a core made of a solid, liquid or gaseous material, and a shell made of a drawable material, said bundle is drawn in order to reduce the diameter of said fibres, a porous matrix is formed around the core of the drawn fibres, the formation of said porous matrix comprising a transformation of the shell material, where said porous matrix comprises at least one population of connected pores interconnecting the channels, where the thickness of the porous matrix between two adjacent channels is less than the diameter of the channels, preferably less than half the diameter of the channels, where necessary the core material is removed so as to leave free channels in the porous matrix.

1 . A method for manufacturing a multicapillary material, comprising:
 providing a plurality of fibres, wherein each fibre comprises a shell made of a material that can be drawn when exposed to heat and a fusible solid core inside the shell;   assembling the plurality of fibres into a bundle;   continuously feeding each of the plurality of fibres into a drawing device;   in the drawing device:   heating a central region of the fibre so as to make the shell material drawable and to melt the core in the central region;   maintaining the core solid in a first end portion of the fibre upstream of the central region;   drawing a second end portion of the fibre downstream of the central region; and   cooling down the second end portion to below a fusion temperature of the core; and   after drawing the plurality of fibres, melting the core and flowing the melt core out of the shell of each of the plurality of fibres so as to form a plurality of capillary channels.   
     
     
         2 . The method of  claim 1 , wherein the step of assembling the plurality of fibres into the bundle is done before feeding the fibres into the drawing device and the bundle is fed as a whole into the drawing device. 
     
     
         3 . The method of  claim 1 , wherein each fibre is drawn separately and the step of assembling the plurality of fibres into the bundle is done after drawing the plurality of fibres. 
     
     
         4 . The method of  claim 1 , wherein the bundle is formed by inserting the plurality of fibres into a tube having a non-porous wall. 
     
     
         5 . The method of  claim 1 , wherein the core comprises a metal. 
     
     
         6 . The method of  claim 5 , wherein the metal comprises at least one of tin, bismuth, indium, gallium and silver. 
     
     
         7 . The method of  claim 1 , wherein the core comprises a polymer or a wax. 
     
     
         8 . The method of  claim 1 , wherein the capillary channels have a mean diameter less than 10 μm. 
     
     
         9 . The method of  claim 1 , further comprising forming a porosity in the shell material of each of the plurality of fibres. 
     
     
         10 . The method of  claim 1 , wherein the shell material comprises glass.