Appearance White crystal substance Mass portion of adipic acid, %, not less than 99.8 Colour (Apha):Max. 5 Temperature of melt, 癈, not less than 152.0 Mass portion of water, %, not more than 0.15 Mass portion of ash, %, not more than 0.0002 Mass portion of nitric acid, %, not more than 0.0003 Mass portion of iron, %, not more than 0.00005 Mass portion of oxalic acid, %, not more than 0.004