Eucalyptol
(ue'' ka lip' tol).
DEFINITION
Eucalyptol is obtained from oil of eucalyptus and from other sources. It contains NLT 98.0% and NMT 100.0% of C10H18O.
IDENTIFICATION
• Add 1 mL of phosphoric acid to 1 mL of Eucalyptol contained in a test tube maintained in an ice bath. A solid white crystalline mass is formed, from which eucalyptol separates upon addition of warm water.
ASSAY
• Procedure
System suitability solution:
0.2 mg/mL of limonene and 0.9 mg/mL of eucalyptol in methanol
Sample solution:
0.9 mg/mL of eucalyptol in methanol
Blank:
Methanol
Chromatographic system
Mode:
GC
Detector:
Flame ionization
Column:
0.32-mm × 60-m fused-silica capillary column coated with phase G16
Temperature:
See Table 1.
Table 1
Injector port temperature:
250
Detector temperature:
250
Split flow rate:
50 mL/min
Carrier gas:
Helium
Column head pressure:
30 psi
Injection size:
1 µL
System suitability
Sample:
System suitability solution
Suitability requirements
Resolution:
NLT 2.0 between limonene and eucalyptol
Column efficiency:
NLT 150,000 theoretical plates, eucalyptol
Analysis
Samples:
Sample solution and Blank
[NoteIdentify any peaks from the Sample solution, that correspond to those in the Blank, by their retention times. ]
Calculate the percentage of eucalyptol (C10H18O) in the portion of Eucalyptol taken:
Result = (rU/rT) × 100
Acceptance criteria:
98.0%100.0%
IMPURITIES
• Limit of Phenols
Analysis 1:
Shake 5 mL with 5 mL of sodium hydroxide TS.
Acceptance criteria 1:
The volume of Eucalyptol is not diminished.
Analysis 2:
Shake 1 mL with 20 mL of water, and allow the liquids to separate. To 10 mL of the water layer, add 1 drop of ferric chloride TS.
Acceptance criteria 2:
The mixture develops no violet color.
SPECIFIC TESTS
• Specific Gravity 841:
0.9210.924
• Congealing Temperature 651:
NLT 0
• Optical Rotation, Angular Rotation 781A:
0.5 to +0.5
• Distilling Range, Method I 721:
174177
• Refractive Index 831:
1.4551.460 at 20
ADDITIONAL REQUIREMENTS
• Packaging and Storage:
Preserve in tight containers.
Auxiliary Information
Please check for your question in the FAQs before contacting USP.
USP35NF30 Page 3149
Pharmacopeial Forum: Volume No. 37(2)
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