Item

Specification

Result

Identification（1）

158.0℃～161.0℃

158.3℃

（2）

According with IR reference spectrum

Qualified

Assay

99.50%～105.00%

99.57%

Appearance

White crystal or powder.

White crystal or powder.

Loss of Drying

≤0.5%

0.27%

Sulfates

≤200ppm

＜200ppm

Sulfate ash

≤0.1%

<0.031%

Chlorides

≤100ppm

＜140ppm

Heavy Metals

≤20ppm

＜20ppm

Related Compounds

1

Phenol

≤0.02%

＜0.01%

2

4-hydroxybenzoic acid

≤0.1%

＜0.1%

3

4-hydroxyisofthalic acid

≤0.05%

＜0.05%

4

Any other impurities

≤0.03%

＜0.05%