ASTM D2379-09(2023)

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: D2379 − 09 (Reapproved 2023)
Standard Test Method for
Acidity of Formaldehyde Solutions
This standard is issued under the fixed designation D2379; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope E29 Practice for Using Significant Digits in Test Data to
Determine Conformance with Specifications
1.1 This test method covers the determination of the acidity
E200 Practice for Preparation, Standardization, and Storage
of commercially available formaldehyde solutions.
of Standard and Reagent Solutions for Chemical Analysis
1.2 For purposes of determining conformance of an ob-
served or a calculated value using this test method to relevant
3. Summary of Test Method
specifications, test result(s) shall be rounded off “to the nearest
3.1 A specimen is titrated with standard alkali to the
unit” in the last right-hand digit used in expressing the
bromthymol blue end point.
specification limit, in accordance with the rounding-off method
of Practice E29.
4. Significance and Use
1.3 The values stated in SI units are to be regarded as
4.1 This test method provides a measurement of acidity (as
standard. No other units of measurement are included in this
formic acid) in formaldehyde solutions. The results of these
standard.
measurements can be used for specification acceptance.
1.4 For hazard information and guidance, see the supplier’s
5. Apparatus
Safety Data Sheet.
5.1 Buret, 25 mL, calibrated in 0.1 mL divisions. A TFE-
1.5 This standard does not purport to address all of the
fluorocarbon resin stopcock is suitable for this purpose.
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
6. Reagents and Materials
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use. 6.1 Purity of Reagents—Reagent grade chemicals shall be
Specific hazard statements are given in Section 7. used in all tests. Unless otherwise indicated, it is intended that
1.6 This international standard was developed in accor- all reagents shall conform to the specifications of the Commit-
dance with internationally recognized principles on standard- tee on Analytical Reagents of the American Chemical Society,
ization established in the Decision on Principles for the
where such specifications are available. Other grades may be
Development of International Standards, Guides and Recom- used, provided it is first ascertained that the reagent is of
mendations issued by the World Trade Organization Technical sufficiently high purity to permit its use without lessening the
Barriers to Trade (TBT) Committee. accuracy of the determination.
6.2 Purity of Water—Reference to water shall be understood
2. Referenced Documents
to mean reagent water conforming to Type IV or better of
2.1 ASTM Standards: Specification D1193.
D1193 Specification for Reagent Water
6.3 Bromthymol Blue Indicator Solution (1.0 g/L)—
D2380 Test Method for Methanol Content of Formaldehyde
Dissolve 0.1 g of the water-soluble form of bromthymol blue
Solutions
indicator powder in 100 mL of water.
6.4 Sodium Hydroxide, Standard Solution (0.1 N)—Prepare
and standardize 0.1 N sodium hydroxide (NaOH) solution as
This test method is under the jurisdiction of ASTM Committee D01 on Paint
described in Practice E200.
and Related Coatings, Materials, and Applications and is the direct responsibility of
Subcommittee D01.35 on Solvents, Plasticizers, and Chemical Intermediates.
Current edition approved July 1, 2023. Published August 2023. Originally
approved in 1965. Last previous edition approved in 2017 as D2379 – 09 (2017). ACS Reagent Chemicals, Specifications and Procedures for Reagents and
DOI: 10.1520/D2379-09R23. Standard-Grade Reference Materials, American Chemical Society, Washington,
For referenced ASTM standards, visit the ASTM website, www.astm.org, or DC. For suggestions on the testing of reagents not listed by the American Chemical
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Society, see Analar Standards for Laboratory Chemicals, BDH Ltd., Poo
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