ASTM D3872-05

Standard Test Method for Ferrous Iron in Iron Oxides

SIGNIFICANCE AND USE
This test method may be used for production quality control or specification acceptance.
SCOPE
1.1 This test method covers the quantitative determination of ferrous oxide (FeO) by oxidation of ferrous iron (Fe++) in an acid solution to the ferric state (Fe+++) and titration with potassium dichromate using diphenylamine as the indicator.
1.2 This test method is applicable to synthetic black iron oxide, natural black iron oxide, magnetite or brown iron oxide where part of the iron content is present in the ferrous state (Note 1). It is applicable to iron oxides where the ferrous iron content ranges from 50 to 0.20 %.
Note 1—Natural iron oxides and magnetite may contain traces of metallic iron that will be combined with and analyzed as FeO.
1.3 This standard does not purport to address the safety concerns if any, problems 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.

General Information

• Status: Historical
• Publication Date: 31-Aug-2005
• Technical Committee: D01 - Paint and Related Coatings, Materials, and Applications
• Drafting Committee: D01.31 - Pigment Specifications

Relations

• Replaces: ASTM D3872-86(1999) - Standard Test Method for Ferrous Iron in Iron Oxides
• Effective Date: 01-Sep-2005
• Replaced By: ASTM D3872-05(2011) - Standard Test Method for Ferrous Iron in Iron Oxides
• Effective Date: 01-Jun-2011
• Referred By: ASTM D769-01(2019) - Standard Specification for Black Synthetic Iron Oxide
• Effective Date: 01-Sep-2005
• Referred By: ASTM D3724-01(2019) - Standard Specification for Synthetic Brown Iron Oxide Pigment
• Effective Date: 01-Sep-2005

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation:D3872–05
Standard Test Method for
1
Ferrous Iron in Iron Oxides
This standard is issued under the fixed designation D3872; 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. Significance and Use
1.1 This test method covers the quantitative determination 3.1 This test method may be used for production quality
++
offerrousoxide(FeO)byoxidationofferrousiron(Fe )inan control or specification acceptance.
+++
acid solution to the ferric state (Fe ) and titration with
4. Apparatus
potassium dichromate using diphenylamine as the indicator.
1.2 This test method is applicable to synthetic black iron 4.1 The digestion apparatus consists of a standard 500-mL
Erlenmeyer flask fitted with a two-hole rubber stopper and
oxide, natural black iron oxide, magnetite or brown iron oxide
where part of the iron content is present in the ferrous state glass tubing, as shown in Fig. 1, to provide for the introduction
of the inert gas and vent for gas and digestion fumes.
(Note 1). It is applicable to iron oxides where the ferrous iron
content ranges from 50 to 0.20 %.
5. Reagents
NOTE 1—Natural iron oxides and magnetite may contain traces of
5.1 Purity of Reagents—Reagent grade chemicals shall be
metallic iron that will be combined with and analyzed as FeO.
used in all tests. Unless otherwise indicated, it is intended that
1.3 This standard does not purport to address the safety
all reagents shall conform to the specifications of the Commit-
concerns if any, problems associated with its use. It is the
tee onAnalytical Reagents of theAmerican Chemical Society,
3
responsibility of the user of this standard to establish appro-
where such specifications are available. Other grades may be
priate safety and health practices and determine the applica-
used, provided it is first ascertained that the reagent is of
bility of regulatory limitations prior to use.
sufficiently high purity to permit its use without lessening the
accuracy of the determination.
2. Referenced Documents
5.2 Purity of Water—Unless otherwise indicated, references
2
2.1 ASTM Standards:
to water shall be understood to mean Type II of Specification
D50 Test Methods for Chemical Analysis of Yellow, Or-
D1193.
ange, Red, and Brown Pigments Containing Iron and
5.3 Diphenylamine Indicator—Dissolve1gof diphenylam-
Manganese
ine in 100 mL of concentrated (H SO ) (sp gr 1.84).
2 4
D280 Test Methods for Hygroscopic Moisture (and Other
5.4 Hydrochloric Acid (1+1)—Dilute concentrated hydro-
Matter Volatile Under the Test Conditions) in Pigments
chloric acid (HCl, sp gr 1.19) with an equal volume of reagent
D769 Specification for Black Synthetic Iron Oxide
water.
D1193 Specification for Reagent Water 4
5.5 Iron Ore, Standard, Sibley No. 27-f.
D3722 Specification for Natural Red and Brown Iron Oxide
5.6 Potassium Dichromate, Standard Solution (0.1 N)—
Pigments
Dissolve 4.904 g of K Cr O in water and dilute to 1 L.
2 2 7
D3724 Specification for Synthetic Brown Iron Oxide Pig-
Standardize against National Institute of Standards and Tech-
ment
nology standard sample No. 27f of Sibley iron ore. Calculate
the Fe factor in grams per millilitre for the solution as:
1
This test method is under the jurisdiction of ASTM Committee D01 on Paint
3
and Related Coatings, Materials, andApplications and is the direct responsibility of Reagent Chemicals, American Chemical Society Specifications, American
Subcommittee D01.31 on Pigment Specifications. Chemical Society, Washington, DC. For suggestions on the testing of reagents not
Current edition approved Sept. 1, 2005. Published September 2005. Originally listed by the American Chemical Society, see Analar Standards for Laboratory
approved in 1979. Last previous edition approved in 1999 as D3872 – 86 (1999). Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
DOI: 10.1520/D3872-05. and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or MD.
4
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM May be secured from National Institute of Standards and Technology, Depart-
Standards volume information, refer to the standard’s Document Summary page on ment of Commerce, Washington, DC 20234. Other recognized primary iron
the ASTM website. standard may be substituted.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
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D3872–05
FIG. 1 Digestion Apparatus
Fe 5 W/V (1)
to avoid g
...