Name of index

FCC-V

E451(i)

Description

White, slightly hygroscopic granules or powder

pH of a 1 % solution

--

9.1-10.2

Assay (drying basis)

1,Anhydrous:≥85.0% 2,Hexahydrate:≥65.0%

1,Anhydrous:≥85.0% 2,Hexahydrate:≥65.0%

P₂O₅ Content ,%

--

1,Anhydrous:56-59% 2,Hexahydrate:43-45%

Lead, ≤%

0.0002

0.0004

Water insoluble ,≤%

0.1

0.1

Higher polyphosphates ≤%

--

1

Fluoride, ≤%

0.005

0.001

Loss on drying ≤

--

1,Anhydrous 0.7% (105°C,1h)

2,Hexahydrate 23.5%(60°C,1h then 105°C,4h)

As,≤%

0.0003

0.0003

Cadmium ≤%

--

0.0001

Mercury ≤%

--

0.0001