Maltol
C6H6O3 126.11
3-Hydroxy-2-methyl-4-pyrone
[118-71-8].
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C6H6O3 126.11
3-Hydroxy-2-methyl-4-pyrone
[118-71-8].DEFINITION
Maltol contains NLT 99.0% of maltol (C6H6O3), calculated on the anhydrous basis.
IDENTIFICATION
• B. Ultraviolet Absorption 
197U
197U
Sample solution:
0.01 mg/mL in 0.1 N hydrochloric acid
Blank:
0.1 N hydrochloric acid
ASSAY
• Procedure
Standard solution:
0.01 mg/mL of USP Maltol RS in 0.1 N hydrochloric acid
Sample solution:
0.01 mg/mL of Maltol in 0.1 N hydrochloric acid
Instrumental conditions
Mode:
UV
Analytical wavelength:
Maximum at about 274 nm
Blank:
0.1 N hydrochloric acid
Analysis
Samples:
Standard solution and Sample solution
Calculate the percentage of maltol (C6H6O3) in the portion of Maltol taken:
Result = (AU/AS) × (CS/CU) × 100
| AU | = | = absorbance of the Sample solution |
| AS | = | = absorbance of the Standard solution |
| CS | = | = concentration of USP Maltol RS in the Standard solution (mg/mL) |
| CU | = | = concentration of the Sample solution (mg/mL) |
Acceptance criteria:
NLT 99.0% on the anhydrous basis
IMPURITIES
• Residue on Ignition 281:
NMT 0.2%, determined on 1.0 g
281:
NMT 0.2%, determined on 1.0 g
• Lead 251:
NMT 10 ppm
251:
NMT 10 ppm
• Heavy Metals, Method II 231:
NMT 20 ppm
231:
NMT 20 ppm
SPECIFIC TESTS
• Melting Range or Temperature, Class Ia 741:
160
–164
741:
160–164
• Water Determination, Method I 921:
NMT 0.5%
921:
NMT 0.5%
ADDITIONAL REQUIREMENTS
• Packaging and Storage:
Preserve in tight containers, protected from light. No storage requirements are specified.
• USP Reference Standards 11
11
USP Maltol 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 1857
Pharmacopeial Forum: Volume No. 31(5) Page 1425