Chemical name: 4,4-Diaminostilbene-2,2-disulfonic acid Chemical formula: C14H14N2O6S2 Molecular weight: 370.4 CAS NO.:81-11-8 Property: 1)Light yellow cream or powder, soluble in ethanol and ether; insoluble in water, easily soluble in alkaline solution. 2)Can be easily oxidized into red; has the property of aromatic acid or aromatic amine Quality index: Item Index (1)Appearance dry/wet light yellow powder/light yellow cream (2)Dry product total amino value(gross dry sample)% 95.0 (3)Degree of pigmentation(EOD) 0.12 (4)Content of alkali insolubles (gross cream )% 0.08 (5)Benzyl compound(gross sample)% 0.25 (6)Ash content% 2.2. Dry product: in 25kg woven bags or upon clients' request; wet product: in 40kg woven bag or upon clients' request.