Zinc Sulfate 10% (w/v) available in 500mL (No. 146682) and 1L (No. 154771) poly bottles.For Nitrogen (Ammonia), For Nitrogen (Organic).ASTM D1426-98 A.APHA 4500-NH3 C.APHA 4500-Norg B (18th Ed.).CAS No.: 7446-20-0.Shelf Life: 24 months.Shipping: No restrictions apply.