Abstract: The present invention provides a method for removing a divalent metal cation from a macromolecular compound having an anionic functional group and containing the divalent metal cation, including (1) suspending a macromolecular compound having an anionic functional group and containing a divalent metal cation in a solution in which an electrolyte that releases an alkali metal ion is dissolved at a concentration at which the macromolecular compound is salted out, and (2) performing, in the obtained suspension, an ion exchange reaction to exchange the divalent metal cation contained in the macromolecular compound with the alkali metal ion.

Abstract: An object of the present invention is to provide a method for producing a peptide with high efficiency, and a method for producing a peptide which comprises the following steps (1) and (2): (1) a step of mixing an N-protected amino acid or an N-protected peptide with a carboxylic acid halide represented by the formula (I) (wherein X represents a halogen atom, R1, R2 and R3 each independently represent an aliphatic hydrocarbon group which may have a substituent, and a total number of the carbon atoms in R1, R2 and R3 is 3 to 40); and (2) a step of mixing the product obtained in the step (1) and a C-protected amino acid or a C-protected peptide is provided.

Abstract: The present invention provides a method for removing a divalent metal cation from a macromolecular compound having an anionic functional group and containing the divalent metal cation, including (1) suspending a macromolecular compound having an anionic functional group and containing a divalent metal cation in a solution in which an electrolyte that releases an alkali metal ion is dissolved at a concentration at which the macromolecular compound is salted out, and (2) performing, in the obtained suspension, an ion exchange reaction to exchange the divalent metal cation contained in the macromolecular compound with the alkali metal ion.

Abstract: Provided is a method for producing a liquid medium composition, including using a junction conduit structure 10 having a structure in which a first inlet conduit 11 and a second inlet conduit 12 are joined together to form an outlet conduit 13, and flowing a first liquid 1 containing a particular compound into the first inflow conduit 11 and flowing a second liquid 2 containing a linking substance into the second inlet conduit 12, and allowing the flows of the both liquids to join together to mix the both liquids, thus forming a liquid medium composition 3 containing structures formed by the particular compound linked via the linking substance dispersed therein while being flown through the outlet conduit 13.