... with reference standard)≥Not lower thanSlightly lower than3Whiteness of dry powder Wg ≥93.090.04Tint reducing power ... 57Water soluble substances,%(m/m) ≤0.50.68pH value of aqueous suspension6.5-8.06.0-8.59Oil ... soluble substances,%(m/m) ≤0.30.58pH value of aqueous suspension6.5-8.06.0-8.59Oil ... sieve 45μm,%(m/m) ≤0.080.2011Resistance of aqueous extract,Ωm ≥5012Rutile content,% ≥9897Application:in ...