ASTM D4450-85(2019)

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: D4450 − 85 (Reapproved 2019)
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 3. Summary of Test Method
3.1 The zinc is determined by dissolving the test sample in
1.1 This test method is intended for the determination of
nitric acid, adjusting the pH of the solution to 5 to 5.5 and
zinc oxide and phosphorous acid content of the pigment
titrating with EDTA.
commercially known as zinc hydroxy phosphite. The zinc
content is determined by ethylenediaminetetraacetate (EDTA) 3.2 The phosphorus is determined colorimetrically with the
aid of nitric acid, ammonium vanadate, and ammonium mo-
titration and calculated as zinc oxide (ZnO), while the phos-
lybdate. The absorbance of the test sample is compared to a
phoruscontentisdeterminedcolorimetricallyandcalculatedas
calibration curve that yields the number of milligrams of
phosphorous acid (H PO ).
3 3
phosphorus.
1.2 The analytical procedures appear in the following order:
Sections
4. Significance and Use
Zinc oxide 6 through 8 4.1 This test method may be used to confirm the stated zinc
Phosphorous acid 9 through 14
oxide and phosphorous acid content of zinc hydroxy phosphite
pigment.
1.3 The values stated in SI units are to be regarded as
standard. No other units of measurement are included in this
5. Purity of Reagents
standard.
5.1 Reagent grade chemicals shall be used in all tests.
1.4 This standard does not purport to address all of the
Unless otherwise indicated, it is intended that all reagents shall
safety concerns, if any, associated with its use. It is the
conform to the specifications of the Committee on Analytical
responsibility of the user of this standard to establish appro-
Reagents of the American Chemical Society, where such
priate safety, health, and environmental practices and deter-
specifications are available. Other grades may be used, pro-
mine the applicability of regulatory limitations prior to use.
vided it is first ascertained that the reagent is of sufficiently
1.5 This international standard was developed in accor-
high purity to permit its use without lessening the accuracy of
dance with internationally recognized principles on standard-
the determination.
ization established in the Decision on Principles for the
5.2 Unless otherwise indicated, references to water shall be
Development of International Standards, Guides and Recom-
understood to mean reagent water conforming to Type II of
mendations issued by the World Trade Organization Technical
Specification D1193.
Barriers to Trade (TBT) Committee.
TOTAL ZINC AS ZINC OXIDE
2. Referenced Documents
2 6. Reagents
2.1 ASTM Standards:
6.1 Ammonium Hydroxide (sp gr 0.90), concentrated ammo-
D1193 Specification for Reagent Water
nium hydroxide (NH OH).
6.2 Glacial Acetic Acid (min 99.7 %), concentrated glacial
acetic acid (CH COOH).
This test method is under the jurisdiction of ASTM Committee D01 on Paint
and Related Coatings, Materials, andApplications and is the direct responsibility of
Subcommittee D01.31 on Pigment Specifications.
Current edition approved Oct. 1, 2019. Published October 2019. Originally
approved in 1985. Last previous edition approved in 2012 as D4450 – 85 (2012). ACS Reagent Chemicals, Specifications and Procedures for Reagents and
DOI: 10.1520/D4450-85R19. Standard-Grade Reference Materials, American Chemical Society, Washington,
For referenced ASTM standards, visit the ASTM website, www.astm.org, or DC. For suggestions on the testing of reagents not listed by theAmerican Chemical
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Society, see Analar Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset,
Standards volume information, refer to the standard’s Document Summary page on U.K., and the United States Pharmacopeia and National Formulary, U.S. Pharma-
the ASTM website. copeial Convention, Inc. (USPC), Rockville, MD.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D4450 − 85 (2019)
6.3 Acid Ammonium Acetate Buffer—Mix 400 mL of dis-
M = molarity of EDTA solution,
tilledwaterand400mLofreagentgradeammoniumhydroxide
S = specimen, g, and
(sp gr 0.90). Add 375 mL of reagent grade glacial acetic acid
0.8137 = milliequivalent weight of zinc oxide.
slowly while stirring.
TOTAL PHOSPHORUS AS PHOSPHOROUS ACID
6.4 Cupric Sulfate Solution (0.1 M)—Dissolve 25 g of
CuSO ·5H O in distilled water and dilute to 1 L.
4 2
9. Reagents
6.5 Disodium Ethylenediaminetetraacetate Dihydrate (0.05
9.1 Standard Phosphorus Solution—Dissolve 0.9156 g of
M)(EDTASolution)—Dissolve18.6gofthereagentgradesalt
secondary sodium phosphate (Na HPO ) in about 200 mL of
2 4
in distilled water and dilute to 1 L. Standardize the solution as
water.Add 20 mL of nitric acid (sp gr 1.42), dilute to 1 L, and
follows:
mix. 1 mL = 0.0002 g P.
6.5.1 Transfer 25 mL of lead standard (6.6) to a 400-mL
9.2 Ammonium Vanadate Solution—Dissolve 2.5 g of am-
beaker.Addconcentratedammoniumhydroxide(6.1)dropwise
monium vanadate (NH VO ) in 500 mL of hot water. When
until a permanent precipitate just forms. Add 25 mL of acid
4 3
ammonium acetate (6.3), dilute to 200 mL, heat to boiling, add solution is complete, add 10 mL nitric acid (sp gr 1.42), cool,
dilute to 1 L, and mix.
4 drops of copper EDTA(6.7) and 12 drops of PAN (6.8), and
titrate with EDTA to a clear yellow.
9.3 Ammonium Molybdate Solution—Dissolve 100 g of
6.5.2 Calculate the molarity of the EDTA, M, as follows:
ammonium molybdate (NH ) Mo O ·4H O in 800 mL of
4 6 7 24 2
M 5 25 30.01036/L 30.20721 (1) water and dilute to 1 L. Filter before use.
where L = EDTA solution, mL. Also 1 mL of primary stan-
9.4 Bromine, reagent grade.
dard 0.05 M lead nitrate = 0.01036 g of lead and 0.20721 is
the milliequivalent weight of lead.
9.5 Bromine Water, distilled water saturated with bromine.
6.6 Primary Standard (0.05 M lead nit
...