Specifications of Butylated Hydroxytoluene USP NF Grade
C15H24O --- 220.35
Phenol, 2,6-bis(1,1-dimethylethyl)-4-methyl-.
2,6-Di-tert-butyl-p-cresol CAS 128-37-0.

Butylated Hydroxytoluene contains not less than 99.0 percent of C15H24O.

Identification: To 10 mL of a solution in methanol (1 in 100,000) add 10 mL of water, 2 mL of sodium nitrite solution (3 in 1000), and 5 mL of dianisidine dihydrochloride solution (1 in 500), prepared by dissolving 200 mg of dianisidine dihydrochloride in a mixture of 40 mL of methanol and 60 mL of 1 N hydrochloric acid: an orange-red color develops within 3 minutes. Add 5 mL of chloroform, and shake: the chloroform layer exhibits a purple or magenta color, which fades when exposed to light.
Congealing temperature: not lower than 69.2, corresponding to not less than 99.0% of C15H24O.
Residue on ignition: Transfer about 50 g, accurately weighed, to a tared crucible, ignite until thoroughly charred, and cool. Moisten the ash with 1 mL of sulfuric acid, and complete the ignition by heating at 800C ± 25C for 15-minute periods to constant weight: the limit is 0.002%.
Heavy metals: 0.001%.

Specifications of Butylated Hydroxytoluene BP Grade
Butylhydroxytoluene Ph Eur
C15H24O --- 220.4 --- CAS 128-37-0
Action and use: Antioxidant.

DEFINITION
Butylhydroxytoluene is 2,6-bis(1,1-dimethylethyl)-4-methylphenol.

CHARACTERS
A white or yellowish-white, crystalline powder, practically insoluble in water, very soluble in acetone, freely soluble in alcohol and in vegetable oils.

IDENTIFICATION
First identification A, C.
Second identification A, B, D.
A. It complies with the test for the freezing-point.
B. Dissolve 0.500 g in ethanol and dilute to 100.0 ml with the same solvent. Dilute 1.0 ml of this solution to 100.0 ml with ethanol. Examined between 230 nm and 300 nm, the solution shows an absorption maximum at 278 nm. The specific absorbance at the maximum is 80 to 90.
C. Examine by infrared absorption spectrophotometry and.
D. Dissolve about 10 mg in 2 ml of alcohol. Add 1 ml of a 1 g/l solution of 17β-Hydroxyandrost-4-en-3-one propionate in alcohol and 2 ml of dilute sodium hydroxide solution. Heat in a waterbath at 80C for 10 min and allow to cool. A blue colour develops.

TESTS
Appearance of solution: Dissolve 1.0 g in methanol and dilute to 10 ml with the same solvent. The solution is clear and not more intensely coloured than reference solution.
Freezing-point: 69C to 70C.
Related substances: To pass the test --- (0.5 per cent).
Sulphated ash: Not more than 0.1 per cent, determined on 1.0 g.

Specifications of BHT Butylated Hydroxytoluene, 2,6-Di-tert-butyl-p-cresol FCC Food Grade
C15H24O, Formula weight 220.35
INS: 321 CAS 128-37-0

DESCRIPTION
BHT occurs as a white, crystalline solid. It is freely soluble in alcohol, and insoluble in water and in propylene glycol.
Function: Antioxidant.

: Dissolve 200 mg of 3,3′-dimethoxybenzidine dihydrochloride in a mixture of 40 mL of methanol and 60 mL of 1 N hydrochloric acid. Add 5 mL of the resulting dianisidine solution to 10 mL of water and 2 mL of a 3:100 solution of sodium nitrite. Add this solution to 10 mL of a 1:100,000 solution of sample methanol. An orange-red color appears within 3 min. Add 5 mL of chloroform, and shake. The chloroform layer exhibits a purple or magenta color that fades when exposed to light.