ASTM D2373-85(1999)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation:D2373–85(Reapproved1999)
Standard Test Method for
Determination of Cobalt in Paint Driers by EDTA Method
This standard is issued under the fixed designation D2373; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope pure liquid cobalt drier soluble in glacial acetic acid and
manufactured for use by the coatings industry.
1.1 This test method covers a titrimetric determination of
cobalt in liquid paint driers that can be dissolved in glacial
5. Apparatus
acetic acid and utilizes the disodium salt of ethylenediamine-
5.1 Centrifuge, capable of developing 1000 to 2000 g.
tetraacetic acid dihydrate (EDTA).
1.2 This test method is not applicable to drier blends. If
6. Reagents
driers other than cobalt are present, they may interfere by
6.1 Purity of Reagents—Reagent grade chemicals shall be
reacting with EDTA under the conditions used for analysis.
used in all tests. Unless otherwise indicated, it is intended that
1.3 All cations that can be titrated with EDTA in alkaline
all reagents shall conform to the specifications of the Commit-
media interfere and must not be present in the sample.
tee onAnalytical Reagents of theAmerican Chemical Society,
1.4 This standard does not purport to address all of the
where such specifications are available. Other grades may be
safety concerns, if any, associated with its use. It is the
used, provided it is first ascertained that the reagent is of
responsibility of the user of this standard to establish appro-
sufficiently high purity to permit its use without lessening the
priate safety and health practices and determine the applica-
accuracy of the determination.
bility of regulatory limitations prior to use.
6.2 Purity of Water—Unlessotherwiseindicated,references
2. Referenced Documents towatershallbeunderstoodtomeanreagentwaterconforming
to Type II of Specification D1193.
2.1 ASTM Standards:
6.3 Ammonium Chloride (NH Cl).
D600 Specification for Liquid Paint Driers
3 6.4 Ammonium Hydroxide (sp gr 0.90)Concentratedammo-
D1193 Specification for Reagent Water
nium hydroxide (NH OH).
E180 Practice for Determining the Precision of ASTM
4 6.5 Buffer Solution (pH 10.0)—Dissolve67.5gofNH Clin
Methods forAnalysis andTesting of Industrial Chemicals
4 water, add 570 mL of concentrated NH OH (sp gr 0.90), and
E300 Practice for Sampling Industrial Chemicals
dilute to 1 L.
3. Summary of Test Method 6.6 Cupric Sulfate, Standard Solution (0.05 M)—Dissolve
12.5 g of cupric sulfate pentahydrate (CuSO ·5H O) in water
4 2
3.1 The liquid drier is dissolved in glacial acetic acid,
and dilute to 1 L.
diluted with isopropyl alcohol and water, and treated with an
6.7 Eriochrome Black-T Indicator—Triturate 0.20 g of the
excess of standard EDTA solution. The excess is titrated with
concentrated dye with 100 g of sodium chloride (NaCl) and
standard cupric sulfate solution using PAN as the metal
store in a tightly stoppered jar.This mixture remains stable for
indicator.
several years.
4. Significance and Use
6.8 EDTA, Standard Solution (0.05 M)—Dissolve 18.62 g
of EDTAin water and dilute to 1 L. Store in a polyethylene or
4.1 The amount of cobalt drier used in oxidizing-type
borosilicate glass bottle.
coatings significantly affects their drying properties. This test
6.9 Glacial Acetic Acid (sp gr 1.06).
method may be used to confirm the stated cobalt content of a
6.10 Isopropyl Alcohol, 99.5%.
This test method is under the jurisdiction of ASTM Committee D-1 on Paint
and Related Coatings, Materials, andApplications and is the direct responsibility of
Subcommittee D01.21 on Chemical Analysis of Paints and Paint Materials. Reagent Chemicals, American Chemical Society Specifications, American
Current edition approved Oct. 25, 1985. Published December 1985. Originally Chemical Society, Washington, DC. For suggestions on the testing of reagents not
published as D2373–65T. Last previous edition D2373–79. listed by the American Chemical Society, see Analar Standards for Laboratory
Annual Book of ASTM Standards, Vol 06.04. Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
Annual Book of ASTM Standards, Vol 11.01. and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,
Annual Book of ASTM Standards, Vol 15.05. MD.
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D2373–85 (1999)
6.11 Methyl Red Indicator Solution—Dissolve 0.2 g of ~M 3 V !
1 3
M 5 (2)
V
methyl red in 100 mL of methanol, ethanol, or isopropanol. 2
6.12 PAN Indicator(1(2-Pyridylazo)-2-Naphthol) Prepare a
where:
dilute solution of the indicator by dissolving 0.10 g in 100 mL
M = molarity of EDTA solution,
of ethanol or isopropanol.
V = EDTA solution, mL, and
6.13 Sodium Acetate Solution—Prepare a saturated aqueous
V = CuSO solution, mL.
2 4
solution of sodium acetate (NaC H O ) in water.
2 3 2
6.14 Sodium Chloride (NaCl). 9. Procedure
6.15 Sodium Hydroxide Solution (80 g/L)—Dissolve80gof
9.1 Check the clarity of the drier. If not clear,
...