| 摘要 |
PROBLEM TO BE SOLVED: To provide a purification method by which a content of metal impurities of a hydrophilic compound with low volatility can be reduced, a production method by which a polymeric compound with a reduced content of metal impurities can be produced, and a photolithographic material with a reduced content of metal impurities.SOLUTION: A purification method for a hydrophilic compound that is liquid or solid at 200°C under atmospheric pressure is provided, which includes the following step (I) and step (II). In step (I), a hydrophilic compound that is liquid or solid at 200°C under atmospheric pressure and contains at least one metal in Na, Ca, Fe and Zn is dissolved in a solvent having a hydroxyl group and a content of 50 mass ppb or less of each metal in Na, Ca, Fe and Zn; and the obtained solution is brought into contact with an anion exchange resin and a cation exchange resin. In step (II), after step (I), crystallization is carried out to recover the hydrophilic compound. |
