ASTM D3970-05(2017)

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Designation: D3970 − 05 (Reapproved 2011) D3970 − 05 (Reapproved 2017)
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
1.1 This test method covers the titrimetric determination of cerium in liquid cerium and rare earth paint driers and utilizes
ferrous ammonium sulfate.
1.2 This test method is not applicable to dryer blends.
1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.4 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 and health practices and determine the applicability of regulatory
limitations prior to use. For a specific hazard statement, see Section 7.
1.5 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.
2. Referenced Documents
2.1 ASTM Standards:
D444 Test Methods for Chemical Analysis of Zinc Yellow Pigment (Zinc Chromate Yellow)
D600 Specification for Liquid Paint Driers
D1193 Specification for Reagent Water
E180 Practice for Determining the Precision of ASTM Methods for Analysis and Testing of Industrial and Specialty Chemicals
(Withdrawn 2009)
E300 Practice for Sampling Industrial Chemicals
3. Summary of Test Method
3.1 The organic constituents of the liquid drier specimen are eliminated by treatment with nitric, sulfuric, and hydrochloric
acids, and the cerium is converted to cerous sulfate. The cerous sulfate is oxidized to ceric sulfate with sodium bismuthate and
titrated with standard ferrous ammonium sulfate.
4. Significance and Use
4.1 This test method may be used to confirm in the presence of rare earths the stated cerium content of liquid pure cerium or
rare earth driers manufactured for use in the coatings industry.
5. Interferences
5.1 This test method is specific for cerium in the presence of rare earth metals. Other drier metals with more than one valence
may interfere and should be absent.
6. Reagents
6.1 Purity of Reagents—Reagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that all
reagents purchased or prepared shall conform to the specifications of the Committee on Analytical Reagents of the American
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, 2011July 1, 2017. Published June 2011July 2017. Originally approved in 1980. Last previous edition approved in 20052011 as
D3970 – 05.D3970 – 05 (2011). DOI: 10.1520/D3970-05R11.10.1520/D3970-05R17.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’sstandard’s Document Summary page on the ASTM website.
The last approved version of this historical standard is referenced on www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D3970 − 05 (2017)
Chemical Society, where such specifications are available. Other grades may be used, provided it is first ascertained that the
reagent is of sufficiently high purity to permit its use without lessening the accuracy of the determination.
6.2 Purity of Water—Unless otherwise indicated, references to water shall be understood to mean reagent water conforming to
Type II of Specification D1193.
6.3 Ceric Sulfate Solution, Standard (0.1 N)—Standardized 0.1 N solutions of ceric sulfate (Ce(SO ) ) in 1 N sulfuric acid may
4 2
be purchased or prepared.
6.4 Ferroin Indicator (0.025 M)—Orthophenanthroline ferrous complex indicator.
6.5 Ferrous Ammonium Sulfate Solution, Standard (0.1 M)—Standardized ferrous ammonium sulfate (FeSO · (NH ) SO ), 0.1
4 4 2 4
M, may be purchased or prepared in the following manner. Dissolve 39.2 g of ferrous ammonium sulfate in 250 mL of distilled
water and add 20 mL of concentrated sulfuric acid with stirring. Dilute to 1 L in a volumetric flask and standardize as follows:
6.5.1 Pipet duplicate 20.0-mL portions of standard 0.1 N ceric sulfate solution into 400-mL beakers and add 200-mL of 1.5 N
sulfuric acid. Titrate with 0.1 N ferrous ammonium sulfate solution as described in 6.69.9. Calculate the molarity, M, of this
approximately 0.1 M solution as follows:
M 5 V N/V (1)
2 1
where:
V = ceric sulfate solution, mL,
N = normality of ceric sulfate solution, and
V = ferrous ammonium sulfate solution, mL.
where:
V = ceric sulfate solution, mL,
N = normality of ceric sulfate solution, and
V = ferrous ammonium sulfate solution, mL.
6.6 Ferrous Ammonium Sulfate Solution, Standard (0.01 M)—(0.01Transfer M)—Transfer 100 mL of the standardized 0.1 M
ferrous ammonium sulfate solution from a volumetric flask to a 1-L volumetric flask and dilute with distilled water. This 0.01 M
ferrous ammonium sulfate solution is designated as M . Alternatively, 0.2 N ferrous ammonium sulfate solution (see Test Methods
D444) may be used and diluted to 0.01 M in accordance with 6.5.
6.7 Hydrochloric Acid (sp gr 1.19)—Concentrated hydrochloric acid (HCl).
6.8 Nitric Acid (sp gr 1.42)—Concentrated nitric acid (HNO ).
6.9 Sodium Bismuthate (NaBiO ) —The grade required is a yellow powdery solid. If it is any other color it has decomposed
and fresh material should be obtained.
6.10 Sulfuric Acid (sp gr 1.84)—Concentrated sulfuric acid (H SO ).
2 4
6.11 Sulfuric Acid (1 + 49, 2 %)—Dilute 10 mL of the concentrated sulfuric acid (H SO ) to 500 mL with water.
2 4
6.12 Sulfuric Acid (1.5 N)—Dilute 16.7 mL of concentrated sulfuric acid (H SO ) to 400 mL with water.
2 4
7. Precautions
7.1 Use only a rubber bulb aspirator for pipetting liquids.
8. Sampling
8.1 Take a small sample of liquid drier from bulk using the procedures in Practice E300 appropriate for the size of container:
Bottle Sampling section for tanks and tank cars or Tube Sampling section for drums and cans.
NOTE 1—Liquid driers are normally homogeneous so that only simple physical tests, such as specific gravity or solids content, on top and bottom
Reagent Chemicals, American Chemical Society Specifications, American Chemical Society, Washington, DC. For suggestions on
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