Abstract: Monodisperse particles having a particle diameter in the range of about from 1 to 1,000 ?m; a process for easily producing the particles; a column for liquid chromatography which is packed with the particles; and a method of liquid chromatography which comprises using the column. The monodisperse particles are obtained by adding an aqueous emulsion containing a polymerizable monomer to monodisperse polymer seed particles comprising a poly((meth)acrylic ester) containing at least one kind of groups selected from the group consisting of straight-chain alkyl groups having 6 or more carbon atoms, alicyclic alkyl groups having 6 or more carbon atoms, phenyl groups, benzyl groups and halogenated alkyl groups having 3 or more carbon atoms to thereby swell the seed particles and then polymerizing the polymerizable monomer.

Abstract: An anion exchanger comprised of a fine particle having a cured polyethyleneimine surface layer formed on the fine particle surface. The cured polyethyleneimine surface layer is formed by the steps of: (1) dispersing a fine particle having a functional group capable of reacting with polyethyleneimine on the fine particle surface, in an aqueous solution of a crosslinking agent capable of crosslinking polyethyleneimine to prepare an aqueous dispersion of the fine particle; and then, (2) adding the polyethyleneimine and a catalyst for crosslinking the polyethyleneimine in the aqueous dispersion of the fine particle, and carrying a reaction of bonding the polyethyleneimine to the functional group on the fine particle surface and a reaction of crosslinking the polyethyleneimine with the crossslinking agent. The anion exchanger is used as a packing for chromatography.

Abstract: An anion exchanger which is a fine particle having bound to the surface thereof a polyamine, preferably polyethyleneimine, having a molecular weight of at least 50,000. The anion exchanger can be produced by binding a polyamine having a number average molecular weight of at least 50,000 to a functional group such as an epoxy group, a halogenated alkyl group and/or an aldehyde group, present on the surface of a fine particle. The anion exchanger is useful as a packing for column chromatography.

Abstract: An anion exchanger comprised of a fine particle having a cured polyethyleneimine surface layer formed on the fine particle surface. The cured polyethyleneimine surface layer is formed by the steps of: (1) dispersing a fine particle having a functional group capable of reacting with polyethyleneimine on the fine particle surface, in an aqueous solution of a crosslinking agent capable of crosslinking polyethyleneimine to prepare an aqueous dispersion of the fine particle; and then, (2) adding the polyethyleneimine and a catalyst for crosslinking the polyethyleneimine in the aqueous dispersion of the fine particle, and carrying a reaction of bonding the polyethyleneimine to the functional group on the fine particle surface and a reaction of crosslinking the polyethyleneimine with the crossslinking agent. The anion exchanger is used as a packing for chromatography.

Abstract: Monodisperse particles having a particle diameter in the range of about from 1 to 1,000 &mgr;m; a process for easily producing the particles; a column for liquid chromatography which is packed with the particles; and a method of liquid chromatography which comprises using the column. The monodisperse particles are obtained by adding an aqueous emulsion containing a polymerizable monomer to monodisperse polymer seed particles comprising a poly((meth)acrylic ester) containing at least one kind of groups selected from the group consisting of straight-chain alkyl groups having 6 or more carbon atoms, alicyclic alkyl groups having 6 or more carbon atoms, phenyl groups, benzyl groups and halogenated alkyl groups having 3 or more carbon atoms to thereby swell the seed particles and then polymerizing the polymerizable monomer.