| 摘要 |
PROBLEM TO BE SOLVED: To enable dimethyl sulfoxide (DMSO) to be used in a specific use such the use in electronics and medicines by purifying the DMSO by using an ammonium sulfonate type resin. SOLUTION: DMSO requiring purification (preferably, the DMSO with a low moisture content of 0.15 wt.% or less of total weight) is brought into contact with a solid consisting essentially of a sulfonic acid type ion exchange resin which has an active group of ammonium sulfonate (SO3 NH4 ) form (preferably, a resin based on a polystyrene-divinylbenzene copolymer) preferably at 19-80 deg.C. Further, a liquid consisting of the refined DMSO in which the content of alkali (alkaline earth) metal cation is extremely low is separated from the solid in the method for purifying the DMSO. By the method, the obtained DMSO having the content of the Fe cation of 1 ppb or less and the content of the Na cation of 2 ppb or less, which are each limit of detection by using a plasma torch atomic emission spectrometry method. |
