Item pulvis index Content of choline chloride: % ≥ 50 Content of total free ammonia(count by CH3 3N), % ≤ 150ppm Content of heavy metal(count by pb), % ≤ 0.002 Loss on drying, % ≤ 1.5-1.9 Granularity(20 sieve)rate of through seive, % ≥ 95The content of choline chloride(powder) count by butt