Inspection items 

Enterprise Standard of our company 

 USP 35

Appearance

Colorless to yellowish, transparent, oily liquid, foreigh odor.

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Solubility

Miscible with methanol, ethanol, hexane and ethyl acetate,
very slightly soluble in water.

 -

Relative density

0.952~0.956

 -

Refractive index

1.5125~1.5145

 -

Freezing point

18~19℃

 -

Clarity in ethanol solution

Clear

 -

Acidity

Methyl red indicator may not appear red in the aqueous
solution.

 -

Related substances

 3,3',5,5'-tetrakis (1-methylethyl) biphenyl4,4'-diol
(Impurity A) ≤ 0.01%;
2,6-bis(1-methylethyl)benzene-1,4-dione
(Impurity B) ≤ 0.05%;
2,6-diisopropylphenyl isopropyl ether (Impurity C)≤ 0.10%;
Total impurities ≤ 0.10%

 3,3',5,5'-tetrakis (1-methylethyl) biphenyl4,4'-diol
(Impurity A) ≤ 0.01%;
2,6-bis(1-methylethyl)benzene-1,4-dione
(Impurity B) ≤ 0.05%;
2,6-diisopropylphenyl isopropyl ether (Impurity C)≤ 0.20%;
Total impurities ≤ 0.30%

Water

≤ 0.1%

 -

Residue on ignition

≤ 0.1%

-

Heavy metals

≤ 10ppm

-

Microbial limit

Total bacterium, moulds and yeasts count less than 100 CFU/ml.

-

Bacterial endotoxins

Less than 6 EU/g

-

Content (HPLC)

≥99.8%

98.0%~102.0%