ITEM

SPECIFICATIONS

RESULTS

Appearance

A colourless or slightly yellow liquid,very slightly soluble in water ,miscible with alcohol and with fatty and essential oils

Complies

Identification A

A crystalline precipitate is formed,and melts 156 ℃ to 161 ℃

Positive

156.9 ~160.3 ℃

Identification B

A violet-red color developed

Positive

Appearance of solution

The solution is clear and not more coloured than reference solution Y7

The solution is clear and coloured ＜ reference

Acidity

0.1M NaOH not more than 0.4ml

0.05ml

Refractive index

1.535 ~1.538 (d_{25 ℃} ^25℃)

          1.5372

Specific gravity

1.180 ~1.185 (20 ℃)

1.183

Heavy metal

≤20ppm

＜20ppm

Assay

Contains C₈H₈O₃ 99.0% ~100.5%

99.2%

Conclusion :The drug superscript meets standards of usp37/BP2010