Butylated Hydroxytoluene
C15H24O 220.35
Phenol, 2,6-bis(1,1-dimethylethyl)-4-methyl-;
2,6-Di-tert-butyl-p-cresol
[128-37-0].
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C15H24O 220.35
Phenol, 2,6-bis(1,1-dimethylethyl)-4-methyl-;
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
197K:
On undried sample
IMPURITIES
• Residue on Ignition 281
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.
for 15-min periods to constant weight.
Acceptance criteria:
NMT 0.002%
• Heavy Metals, Method II 231:
NMT 10 ppm
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
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
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
11
USP Butylated Hydroxytoluene RS 
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Auxiliary Information—
Please check for your question in the FAQs before contacting USP.
| Topic/Question | Contact | Expert Committee |
|---|---|---|
| Monograph | Robert H. Lafaver, M.S.
Scientific Liaison 1-301-816-8335 |
(EXC2010) Monographs - Excipients |
| Reference Standards | RS Technical Services 1-301-816-8129 rstech@usp.org |
USP35–NF30 Page 1718
Pharmacopeial Forum: Volume No. 34(1) Page 130