Item

Standard

Result

 Identification

Positive

Complies

 Melting point of °C

226-230

227.2-229.5

 Appearance

White crystal

White crystal

Content%

99.0-101.0

99.58

 Water%

≤15

13.92

 Ammonium Salts

≤25ppm

15ppm

 Heavy metals

≤10ppm

5ppm

 Arsenic

≤2ppm

0.1ppm

 Lead

≤2ppm

0.1ppm

 Free acid or alkali

Complies with BP/USP/EP

Complies

 Benzoate and salicylate

No precipitate or violet color appears

Complies

 Readily carbonizable substances

Not more intensely colored than reference

Complies

 P-Toluene sulfonamide

≤10ppm

6ppm

 O-Toluene sulfonamide

≤10ppm

5ppm

 Selenium

≤30ppm

5ppm

 Benzoic acid-sulfonamide

≤25ppm

15ppm

 Solubility

Freely soluble in water, sparingly soluble in ethanol

Complies

 Clarity and color of solution

Colorless, clear

Complies