... place. The quality and technical index: Content(as DMSO), % : ≥ 99.8 Crystallization point, : ≥ 18.10 Acid value (0.1N/ml ... The quality and technical index:Item Index StandardContent(as DMSO), %: ≥ 99.9 Crystallization point, : ≥ 18.3 Refractive index: 1.478~~1. ... .The quality and technical index:Item Index StandardContent(as DMSO), %: ≥ 99.9 Crystallization point, : ≥ 18.35 Acid value(mgKOH/g): ≤ 0. ...