ASTM D3970-05(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: D3970 − 05 (Reapproved 2023)
Standard Test Method for
Cerium in Paint Driers by Oxidimetric Determination
This standard is issued under the fixed designation D3970; 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 3. Summary of Test Method
1.1 This test method covers the titrimetric determination of
3.1 The organic constituents of the liquid drier specimen are
cerium in liquid cerium and rare earth paint driers and utilizes
eliminated by treatment with nitric, sulfuric, and hydrochloric
ferrous ammonium sulfate.
acids, and the cerium is converted to cerous sulfate. The cerous
sulfate is oxidized to ceric sulfate with sodium bismuthate and
1.2 This test method is not applicable to dryer blends.
titrated with standard ferrous ammonium sulfate.
1.3 The values stated in SI units are to be regarded as the
standard. The values given in parentheses are for information
4. Significance and Use
only.
4.1 This test method may be used to confirm in the presence
1.4 This standard does not purport to address all of the
of rare earths the stated cerium content of liquid pure cerium or
safety concerns, if any, associated with its use. It is the
rare earth driers manufactured for use in the coatings industry.
responsibility of the user of this standard to establish appro-
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use. 5. Interferences
For a specific hazard statement, see Section 7.
5.1 This test method is specific for cerium in the presence of
1.5 This international standard was developed in accor-
rare earth metals. Other drier metals with more than one
dance with internationally recognized principles on standard-
valence may interfere and should be absent.
ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom-
6. Reagents
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
6.1 Purity of Reagents—Reagent grade chemicals shall be
used in all tests. Unless otherwise indicated, it is intended that
2. Referenced Documents
all reagents purchased or prepared shall conform to the
2.1 ASTM Standards:
specifications of the Committee on Analytical Reagents of the
D444 Test Methods for Chemical Analysis of Zinc Yellow
American Chemical Society, where such specifications are
Pigment (Zinc Chromate Yellow)
available. Other grades may be used, provided it is first
D600 Specification for Liquid Paint Driers (Withdrawn
ascertained that the reagent is of sufficiently high purity to
2021)
permit its use without lessening the accuracy of the determi-
D1193 Specification for Reagent Water
nation.
E180 Practice for Determining the Precision of ASTM
6.2 Purity of Water—Unless otherwise indicated, references
Methods for Analysis and Testing of Industrial and Spe-
to water shall be understood to mean reagent water conforming
cialty Chemicals (Withdrawn 2009)
to Type II of Specification D1193.
E300 Practice for Sampling Industrial Chemicals
This test method is under the jurisdiction of ASTM Committee D01 on Paint
and Related Coatings, Materials, and Applications and is the direct responsibility of
Subcommittee D01.21 on Chemical Analysis of Paints and Paint Materials.
Current edition approved June 1, 2023. Published June 2023. Originally
approved in 1980. Last previous edition approved in 2017 as D3970 – 05 (2017).
DOI: 10.1520/D3970-05R23.
2 4
For referenced ASTM standards, visit the ASTM website, www.astm.org, or ACS Reagent Chemicals, Specifications and Procedures for Reagents and
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standard-Grade Reference Materials, American Chemical Society, Washington,
Standards volume information, refer to the standard’s Document Summary page on DC. For suggestions on the testing of reagents not listed by the American Chemical
the ASTM website. Society, see Analar Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset,
The last approved version of this historical standard is referenced on U.K., and the United States Pharmacopeia and National Formulary, U.S. Pharma-
www.astm.org. copeial Convention, Inc. (USPC), Rockville, MD.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D3970 − 05 (2023)
6.3 Ceric Sulfate Solution, Standard (0.1 N)—Standardized 6.12 Sulfuric Acid (1.5 N)—Dilute 16.7 mL of concentrated
0.1 N solutions of ceric sulfate (Ce(SO ) ) in 1 N sulfuric acid sulfuric acid (H SO ) to 400 mL with water.
4 2 2 4
may be purchased or prepared.
7. Precautions
6.4 Ferroin Indicator (0.025 M)—Orthophenanthroline fer-
6 7.1 Use only a rubber bulb aspirator for pipetting liquids.
rous complex indicator.
8. Sampling
6.5 Ferrous Ammonium Sulfate Solution, Standard (0.1
M)—Standardized ferrous ammonium sulfate (FeSO ·
8.1 Take a small sample of liquid drier from bulk using the
(NH ) SO ), 0.1 M, may be purchased or prepared in the
4 2 4 procedures in Practice E300 appropriate for the size of con-
following manner. Dissolve 39.2 g of ferrous ammonium
tainer: Bottle Sampling section for tanks and tank cars or Tube
sulfate in 250 mL of distilled water and add 20 mL of
Sampling section for drums and cans.
concentrated sulfuric acid with stirring. Dilute to 1 L in a
NOTE 1—Liquid driers are normally homogeneous so that only simple
volumetric flask and standardize as follows:
physical tests, such as specific gravity or solids content, on top and bottom
6.5.1 Pipet duplicate 20.0 mL portions of standard 0.1 N
samples from tanks are required to confirm that separation has not
ceric sulfate solution into 400 mL beakers and add 200 mL of
occurred. Agitate drums in accordance with the Tube Sampling section of
1.5 N sulfuric acid. Titrate with 0.1 N ferrous ammonium Practice E300.
sulfate solution as described in 6.6. Calculate the molarity, M,
8.2 Examine the sample of drier for sediment or suspended
of this approximately 0.1 M solution as follows:
matter which, if present, is evidence of noncompliance with the
Physical Appearance requirements section of Specification
M 5 V N/V (1)
2 1
D600.
where:
8.3 If the sample is homogeneous keep it in a stoppered
V = ceric sulfate solution, mL,
vessel to prevent solvent evaporation prior to analysis.
N = normality of ceric sulfate solution, and
V = ferrous ammonium sulfate solution, mL.
9. Procedure
6.6 Ferrous Ammonium Sulfate Solution, Standard (0.01
9.1 For the analysis use 1.0 g for 6 % of cerium and 2.0 g or
M)—Transfer 100 mL of the standardized 0.1 M ferrous am-
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