Abstract: Disclosed is an aqueous solution as an eluent used in liquid chromatography for analysis of a specimen obtained from a human living body, comprising a mixture of acetonitrile and an aqueous solution of a member selected from the group consisting of acetic acid, a polybasic organic acid, a salt of organic acid and ammonium carbonate.

Abstract: A novel crosslinked polymeric substance and a process for preparing the novel crosslinked polymeric substance are disclosed, the novel crosslinked polymeric substance being prepared from natural chitin or regenerated chitin and the polymeric substance having an amphoteric capability.

Abstract: A shaped material is described having at least a surface layer which consists essentially of an acylated mixture of two or more kinds of chitin derivatives represented by the following formula (1):[(C.sub.6 H.sub.8 O.sub.3 .multidot.(NH.sub.2).sub.x .multidot.(NHCOCH.sub.3).sub.y .multidot.(OR).sub.b ].sub.n (1)wherein R represents a carboxyalkyl group with two to four carbon atoms, a hydroxyethyl group, a hydroxypropyl group, a dihydroxypropyl group or an alkyl group with one to three carbon atoms, x is a number of 0.1 to 1.0, y=1.0-x, a is a number of 0 to 1.0, and b=1.0-a,or a salt thereof.

Abstract: Disclosed herein is a novel shaped material of a derivative of chitin obtainable by partially acylating or partially acid-treating a cross-linked ionic chitin derivatives, which is excellent for use as the material for capsules, as material for dialysis carriers and/or as an ion-exchanger resin.

Abstract: A novel crosslinked polymeric substance and a process for preparing the novel crosslinked polymeric substance are disclosed, the novel crosslinked polymeric substance being prepared from natural chitin or regenerated chitin and the polymeric substance having an amphoteric capability.

Abstract: A spherically shaped material at least the surface layer of which comprises an acylated product of de-N-acetylated chitin. The spherical material is insoluble in water, acids, alkaline solutions and organic solvents. The materials can be employed to separate materials on a column, as a base material on which enzyme is immobilized and as an adsorbent, etc.

Abstract: A process for producing a porous shaped material of acylated chitin derivative wherein a soluble derivative of chitin is acylated, characterized in that an aqueous solution of the derivative of chitin containing a diluent, a porosity-regulating agent and a surfactant is added into a solution of an organic acid anhydride containing a surfactant.

Abstract: A shaped material at the least of which surface layer comprises a denatured chitin obtained by acylation of de-N-acetylated etherified chitin represented by the following general formula:[C.sub.6 H.sub.8 O.sub.3 (NH.sub.2).sub.x (NHCOCH.sub.3).sub.y (OR).sub.a (OH).sub.b ].sub.nwherein R represents a carboxyalkyl group with two to four carbon atoms, a hydroxyethyl group, a hydroxypropyl group, a dihydroxypropyl group or an alkyl group with one to three carbon atoms, x is a number of 0.1 to 1.0, y=1.0-x, a is a number of 0.1 to 1.0, and b=1.0-a,or a salt thereof.

Abstract: Disclosed herein a method for preparing carboxyalkylated chitin from chitin and a method for preparing a de-acetylated substance of the carboxyalkylated chitin.

Abstract: This invention relates to a poly-ion complex comprising chitin or N-acylchitosan derivative having carboxymethyl and polyelectrolyte.