E 1775 (OTTO) Europium(III) sulphate, octahydrate, 99.99% Cas 10031-55-7 - used in computer monitors and televisions. E 1775 (OTTO) Europium(III) sulphate, octahydrate, 99.99% Cas 10031-55-7 - used as a phosphor activator for color cathode-ray tubes and liquid-crystal displays.