ASTM D4450-85(2012)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: D4450 − 85 (Reapproved 2012)
Standard Test Method for
Analysis of Zinc Hydroxy Phosphite Pigment
This standard is issued under the fixed designation D4450; 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 lybdate. The absorbance of the test sample is compared to a
calibration curve that yields the number of milligrams of
1.1 This test method is intended for the determination of
phosphorus.
zinc oxide and phosphorous acid content of the pigment
commercially known as zinc hydroxy phosphite. The zinc
4. Significance and Use
content is determined by ethylenediaminetetraacetate (EDTA)
4.1 This test method may be used to confirm the stated zinc
titration and calculated as zinc oxide (ZnO), while the phos-
phoruscontentisdeterminedcolorimetricallyandcalculatedas oxide and phosphorous acid content of zinc hydroxy phosphite
pigment.
phosphorous acid (H PO ).
3 3
1.2 The analytical procedures appear in the following order:
5. Purity of Reagents
Sections
5.1 Reagent grade chemicals shall be used in all tests.
Zinc oxide 6 through 8
Unless otherwise indicated, it is intended that all reagents shall
Phosphorous acid 9 through 14
conform to the specifications of the Committee on Analytical
1.3 The values stated in SI units are to be regarded as
Reagents of the American Chemical Society, where such
standard. No other units of measurement are included in this
specifications are available. Other grades may be used, pro-
standard.
vided it is first ascertained that the reagent is of sufficiently
1.4 This standard does not purport to address all of the
high purity to permit its use without lessening the accuracy of
safety concerns, if any, associated with its use. It is the the determination.
responsibility of the user of this standard to establish appro-
5.2 Unless otherwise indicated, references to water shall be
priate safety and health practices and determine the applica-
understood to mean reagent water conforming to Type II of
bility of regulatory limitations prior to use.
Specification D1193.
2. Referenced Documents TOTAL ZINC AS ZINC OXIDE
2.1 ASTM Standards:
6. Reagents
D1193 Specification for Reagent Water
6.1 Ammonium Hydroxide (sp gr 0.90), concentrated ammo-
3. Summary of Test Method nium hydroxide (NH OH).
6.2 Glacial Acetic Acid (min 99.7 %), concentrated glacial
3.1 The zinc is determined by dissolving the test sample in
acetic acid (CH COOH).
nitric acid, adjusting the pH of the solution to 5 to 5.5 and
titrating with EDTA.
6.3 Acid Ammonium Acetate Buffer—Mix 400 mL of dis-
tilledwaterand400mLofreagentgradeammoniumhydroxide
3.2 The phosphorus is determined colorimetrically with the
(sp gr 0.90). Add 375 mL of reagent grade glacial acetic acid
aid of nitric acid, ammonium vanadate, and ammonium mo-
slowly while stirring.
6.4 Cupric Sulfate Solution (0.1 M)—Dissolve 25 g of
CuSO ·5H O in distilled water and dilute to 1 L.
This test method is under the jurisdiction of ASTM Committee D01 on Paint
4 2
and Related Coatings, Materials, andApplications and is the direct responsibility of
Subcommittee D01.31 on Pigment Specifications.
Current edition approved Nov. 1, 2012. Published November 2012. Originally
approved in 1985. Last previous edition approved in 2007 as D4450 – 85 (2007) Reagent Chemicals, American Chemical Society Specifications, American
DOI: 10.1520/D4450-85R12. Chemical Society, Washington, DC. For suggestions on the testing of reagents not
For referenced ASTM standards, visit the ASTM website, www.astm.org, or listed by the American Chemical Society, see Analar Standards for Laboratory
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
Standards volume information, refer to the standard’s Document Summary page on and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,
the ASTM website. MD.
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D4450 − 85 (2012)
6.5 Disodium Ethylenediaminetetraacetate Dihydrate (0.05 TOTAL PHOSPHORUS AS PHOSPHOROUS ACID
M)(EDTASolution)—Dissolve18.6gofthereagentgradesalt
9. Reagents
in distilled water and dilute to 1 L. Standardize the solution as
9.1 Standard Phosphorus Solution—Dissolve 0.9156 g of
follows:
secondary sodium phosphate (Na HPO ) in about 200 mL of
2 4
6.5.1 Transfer 25 mL of lead standard (6.6) to a 400-mL
water.Add 20 mL of nitric acid (sp gr 1.42), dilute to 1 L, and
beaker.Addconcentratedammoniumhydroxide(6.1)dropwise
mix. 1 mL = 0.0002 g P.
until a permanent precipitate just forms. Add 25 mL of acid
9.2 Ammonium Vanadate Solution—Dissolve 2.5 g of am-
ammonium acetate (6.3), dilute to 200 mL, heat to boiling, add
monium vanadate (NH VO ) in 500 mL of hot water. When
4 drops of copper EDTA(6.7) and 12 drops of PAN (6.8), and 4 3
solution is complete, add 10 mL nitric acid (sp gr 1.42), cool,
titrate with EDTA to a clear yellow.
dilute to 1 L, and mix.
6.5.2 Calculate the molarity of the EDTA, M, as follows:
9.3 Ammonium Molybdate Solution—Dissolve 100 g of
M 5 25 30.01036/L 30.20721 (1)
ammonium molybdate (NH ) Mo O ·4H O in 800 mL of
4 6 7 24 2
where L = EDTA solution, mL. Also 1 mL of primary stan-
water and dilute to 1 L. Filter before use.
dard 0.05 M lead nitrate = 0.01036 g of lead and 0.20721 is
the milliequivalent weight of lead.
9.4 Bromine, reagent grade.
6.6 Primary Standard (0.05 M lead nitrate)—Dissolve
9.5 Bromine Water, distilled water saturated with bromine.
16.5615 g reagent grade lead nitrate in distilled water and
9.6 Nitric Acid (sp gr 1.42), concentrated nitric acid
dilute to 1 L (1 mL = 0.01036 g lead).
(HNO ).
6.7 Copper-EDTA Solution—Mix equivalent amounts of
9.7 Nitric Acid (2:3)—Dilute 200 mL of nitric acid (sp gr
cupric sulfate solution (6.4)
...