ASTM E3334-22

Standard Test Method for Acidity in Ethanol and Ethanol Solutions

SIGNIFICANCE AND USE
5.1 This test method measures acidity quantitatively. Very dilute aqueous solutions of low molecular mass organic acids, such as acetic acid, are highly corrosive to many metals.  
5.2 Acceptable levels of acidity in ethanol can vary with different specifications, but in general, it is below 200 mg/kg (ppm). Knowledge of the acidity can be required to establish whether the product quality meets specification.
SCOPE
1.1 This test method covers the determination of acidity as acetic acid in ethanol and ethanol solutions. This test method may be applied to ethanol samples containing very little water (dehydrated alcohols) to solutions with significant water (low proof ethanol samples). The solutions include denatured alcohols such as the U.S. denatured ethanol formulas defined in 27.CFR.Part 21. This test method is used for determining low levels of acidity, below 200 m⁄kg (ppm mass), with the exclusion of carbon dioxide.  
1.1.1 Procedure A—Developed specifically for measurement of acidity by potentiometric titration. This is the referee method.  
1.1.2 Procedure B—Developed specifically for measurement of acidity by color end point titration.  
1.2 The ethanol may be analyzed directly by this test method with minimal sample preparation.  
1.3 Review the current and appropriate Safety Data Sheets (SDS) for detailed information concerning toxicity, first aid procedures, and safety precautions and proper personal protective equipment.  
1.4 Units—The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. Some specific hazards statements are given in Section 7 on Hazards.  
1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 31-Dec-2021
• ICS: 71.080.40 - Organic acids
• Technical Committee: E48 - Bioenergy and Industrial Chemicals from Biomass
• Drafting Committee: E48.A0 - Product Specifications

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: E3334 − 22
Standard Test Method for
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Acidity in Ethanol and Ethanol Solutions
This standard is issued under the fixed designation E3334; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 2. Referenced Documents
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1.1 This test method covers the determination of acidity as 2.1 ASTM Standards:
acetic acid in ethanol and ethanol solutions. This test method D770Specification for Isopropyl Alcohol
may be applied to ethanol samples containing very little water D1193Specification for Reagent Water
(dehydrated alcohols) to solutions with significant water (low D7795Test Method for Acidity in Ethanol and Ethanol
proof ethanol samples). The solutions include denatured alco- Blends by Titration
hols such as the U.S. denatured ethanol formulas defined in E200Practice for Preparation, Standardization, and Storage
27.CFR.Part 21. This test method is used for determining low of Standard and Reagent Solutions for ChemicalAnalysis
levels of acidity, below 200 m⁄kg (ppm mass), with the
2.2 U.S. Federal Standards:
exclusion of carbon dioxide.
United States Code of Federal Regulations, Title 27, Part
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1.1.1 Procedure A—Developed specifically for measure-
21Formulas for Denatured Alcohol and Rum
ment of acidity by potentiometric titration. This is the referee
United States PharmacopeiaGeneral Chapters Alcohol De-
4
method.
termination
1.1.2 Procedure B—Developed specifically for measure-
3. Terminology
ment of acidity by color end point titration.
3.1 Definitions:
1.2 The ethanol may be analyzed directly by this test
3.1.1 acidity, n—the quality, state, or degree of being acid.
method with minimal sample preparation.
3.1.1.1 Discussion—The amount of acid titrated with a
1.3 Review the current and appropriate Safety Data Sheets
strong base (NaOH or KOH) in a sample, calculated as acetic
(SDS) for detailed information concerning toxicity, first aid
acid in mg/kg (ppm mass).
procedures, and safety precautions and proper personal protec-
3.1.2 ethanol, n—ethyl alcohol, the chemical compound
tive equipment.
C H OH.
2 5
1.4 Units—The values stated in SI units are to be regarded
3.2 Abbreviations:
asstandard.Nootherunitsofmeasurementareincludedinthis
3.2.1 KHC H O —KHP-Potassium Hydrogen Phthalate
8 4 4
standard.
3.2.2 NaOH—Sodium Hydroxide
1.5 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the 3.2.3 KOH—Potassium Hydroxide
responsibility of the user of this standard to establish appro-
4. Summary of Test Method
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use.
4.1 Samples are purged with nitrogen prior to and during
Some specific hazards statements are given in Section 7 on
titrationfortheeliminationofcarbondioxideandthenaknown
Hazards.
amountofethanolsampleisanalyzedpotentiometricallyeither
1.6 This international standard was developed in accor-
using a monotonic or dynamic end point titrant addition, as
dance with internationally recognized principles on standard-
specified in Procedure A, or by color end point titration, as
ization established in the Decision on Principles for the
specified in Procedure B, using a strong base (NaOH or KOH)
Development of International Standards, Guides and Recom-
solution.Acidcontentiscalculatedasmilligramsofaceticacid
mendations issued by the World Trade Organization Technical
per kilogram of sample.
Barriers to Trade (TBT) Committee.
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For referenced ASTM standards, visit the ASTM website, www.astm.org, or
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This test method is under the jurisdiction of ASTM Committee E48 on contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
BioenergyandIndustrialChemicalsfromBiomassandisthedirectresponsibilityof Standards volume information, refer to the standard’s Document Summary page on
Subcommittee E48.A0 on Product Specifications. the ASTM website.
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Current edition approved Jan. 1, 2022. Published February 2022. DOI: 10.1520/ Available from https://www.ecfr.gov/.
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E3334-22. Available from USP, https://www.usp.org/.
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E3334 − 22
5. Significance and Use 7. Hazards
5.1 This test method measures acidity quantitatively. Very
7.1 Each analyst shall be acquainted with the potential
dilute aqueous solutions of low
...