Butylated Hydroxytoluene (BHT) CAS 128-37-0 Purity >99.5% (GC) Antioxidant

Butylated Hydroxytoluene
C15H24O 220.35
2,6-Di-tert-butyl-p-Cresol [128-37-0].
DEFINITION
Butylated Hydroxytoluene contains NLT 99.0% of C15H24O.
IDENTIFICATION
• A. Infrared Absorption <197K>: On undried sample
IMPURITIES
• Residue on Ignition <281>
Analysis: Transfer 50 g 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 800 ± 25 for 15-min periods to constant weight.
Acceptance criteria: NMT 0.002%
• Heavy Metals, Method II <231>: NMT 10 ppm
• Organic Impurities
Solution A: 50 mg/mL of potassium ferricyanide
Solution B: 105 mg/mL of ferric chloride
Sample solution: 20 mg/mL of Butylated Hydroxytoluene in methanol
Standard solution: 0.1 mg/mL of Butylated Hydroxytoluene from the Sample solution diluted with methanol
Chromatographic system
(See Chromatography <621>, Thin-Layer Chromatography.)
Mode: TLC
Absorbent: 0.25-mm layer of chromatographic silica gel mixture
Developing solvent system: Methylene chloride
Application volume: 10 µL
Spray reagent: Solution A, Solution B, and water (1:2:7), freshly prepared
Analysis
Samples: Sample solution and Standard solution
Apply the Samples, and allow to dry. Place the plate in the chromatographic chamber, and develop until the solvent front has moved three-fourths of the length of the plate. Remove the plate, and allow the plate to dry. Spray the plate with Spray reagent.
Acceptance criteria: Any spot from the Sample solution, apart from the principal spot, is not more intense than the spot from the Standard solution (NMT 0.5%).
SPECIFIC TESTS
• Congealing Temperature <651>: NLT 69.2, corresponding to NLT 99.0% of C15H24O
ADDITIONAL REQUIREMENTS
• Packaging and Storage: Preserve in well-closed containers.
• USP Reference Standards <11>
USP Butylated Hydroxytoluene RS