ASTM D3280-85(2009)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: D3280 − 85 (Reapproved2009)
Standard Test Methods for
Analysis of White Zinc Pigments
This standard is issued under the fixed designation D3280; 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.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope D280 Test Methods for Hygroscopic Moisture (and Other
Matter Volatile Under the Test Conditions) in Pigments
1.1 These test methods cover procedures for the analysis of
D1193 Specification for Reagent Water
white zinc pigments.
D1394 Test Methods for Chemical Analysis of White Tita-
1.2 The analytical procedures appear in the following order:
nium Pigments
Section
E11 Specification for Woven Wire Test Sieve Cloth and Test
Preparation of Sample 6
Sieves
Zinc Oxide
Total Zinc, Using Diphenylamine as Internal Indicator 7
Total Zinc, Using Uranyl Acetate as External Indicator 8
3. Summary of Test Method
Total Impurities 9
Total Sulfur 10 3.1 Zinc Oxide:
Moisture and Other Volatile Matter 11
3.1.1 Total Zinc—Determined using diphenylamine as an
Leaded Zinc Oxide
internal indicator and also using uranyl acetate as an external
Total Lead 12
Total Zinc 13 indicator. Total impurities are calculated.
Total Sulfur 14
3.1.2 Total Sulfur—Determined as BaSO and calculated to
Total Impurities 15
sulfur.
Moisture and Other Volatile Matter 16
Water-Soluble Salts 17 3.1.3 Moisture and Volatile Matter—Determined in accor-
Zinc Sulfide
dance with Method A of Test Methods D280.
Zinc Oxide 18
Zinc Sulfide 19
3.2 Leaded Zinc Oxide:
Water-Soluble Salts 20
3.2.1 Total Lead—Determined as PbSO and calculated to
Moisture and Other Volatile Matter 21
percent PbO.
Barium Sulfate 22
Titanium Dioxide 23
3.2.2 Total Zinc—Determined on the filtrate from procedure
1.3 The values stated in SI units are to be regarded as the in 13.2.1 in accordance with methods in Sections 7 or 8.
3.2.3 Total Sulfur—Determined as BaSO and calculated to
standard. The values given in parentheses are for information
only. percent SO .
3.2.4 Total Impurities—Calculatedfromcompositionaldata.
1.4 This standard does not purport to address all of the
3.2.5 Moisture and Other Volatile Matter—Determined in
safety concerns, if any, associated with its use. It is the
accordance with Method A of Test Methods D280.
responsibility of the user of this standard to establish appro-
3.2.6 Water Soluble Salts—Determined gravimetrically.
priate safety and health practices and determine the applica-
3.3 Zinc Sulfide:
bility of regulatory limitations prior to use.
3.3.1 Total Zinc—Determined using uranyl acetate external
2. Referenced Documents
indicator in accordance with Section 9.
3.3.2 Zinc Sulfide—Determined in accordance with Sections
2.1 ASTM Standards:
8 or 9 and calculating ZnO to ZnS.
3.3.3 Water Soluble Salts—Determined in accordance with
These test methods are under the jurisdiction of ASTM Committee D01 on
Section 18.
Paint and Related Coatings, Materials, and Applications and are the direct
3.3.4 Moisture—Determined in accordance with Method A
responsibility of Subcommittee D01.31 on Pigment Specifications.
of Test Methods D280.
Current edition approved July 1, 2009. Published July 2009. Originally approved
ε1
3.3.5 Barium Sulfate—The sample is treated with N SO
in 1973. Last previous edition approved in 2004 as D3280 – 85 (2004) . DOI:
2 4
10.1520/D3280-85R09.
and Na CO and the residue of BaCO is dissolved in NCl and
2 3 3
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
(NH ) SO added to precipitate BaSO , which is weighed.
4 2 4 4
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
3.3.6 Titanium Dioxide—Determined in accordance with
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. Test Methods D1394.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D3280 − 85 (2009)
NOTE 1—Detailed requirements for this sieve are given in Specification
4. Significance and Use
E11.
4.1 White zinc pigments find considerable use in white
6.3 Preserve all samples in stoppered bottles or containers.
paints, and as such it is useful to formulators and users to be
able to monitor the amounts of these pigments in whole paints.
ZINC OXIDE
It is also of interest to raw material suppliers and paint
producers to check the specifications of each pigment.
7. Total Zinc, Using Diphenylamine as Internal Indicator
5. Reagents
7.1 Reagents:
7.1.1 Diphenylamine Indicator Solution (10 g/L))—
5.1 Purity of Reagents—Reagent grade chemicals shall be
Dissolve1gof diphenylamine in 100 mL of H SO .
2 4
used in all tests. Unless otherwise indicated, it is intended that
7.1.2 Potassium Ferrocyanide (1 mL = 0.008 g Zn)—
all reagents shall conform to the specifications of the Commit-
Dissolve 35 g of K Fe(CN) ·3H O in water and dilute to 1 L
tee onAnalytical Reagents of theAmerican Chemical Society, 4 6 2
and add 0.3 g of potassium ferricyanide (K Fe(CN) ). Stan-
3 6
where such specifications are available. Other grades may be
dardize the solution by titrating against zinc (320 to 340 mg),
used, provided it is first ascertained that the reagent is of
following the procedure described in 7.2. Calculate the grams
sufficiently high purity to permit its use without lessening the
of zinc equivalent to 1.00 mL of the solution.
accuracy of the determination.
7.2 Procedure—Weigh to 0.1 mg about 0.4 g of the sample
5.2 Purity of Water—Unless otherwise indicated, references
into a tall form 400-mL beaker. Moisten with about 20 mL of
to water shall be understood to mean Type II reagent grade
water, and dissolve in 15 mLof HCl. Neutralize with NH OH,
water conforming to Specification D1193.
usinglitmusastheindicator.Addanexcessof15mLofH SO
2 4
5.3 Concentration of Reagents:
(1+2) and dilute to 200 mL. Heat to approximately 60°C, add
5.3.1 Concentrated Acids and Ammonium Hydroxide—
2 drops of diphenylamine indicator solution and while stirring
When acids and ammonium hydroxide are specified by name
vigorously, titrate with K Fe(CN) solution to the color change
4 6
or chemical formula only it should be understood that concen-
from purple to a persistent yellowish green.
trated reagents of the following specific gravities or concen-
NOTE 2—The true end point is a sharp, persistent change from a purple
trations are intended:
to a yellowish green. At the beginning of the titration, a deep blue color
Acetic acid, HC H O 99.5 %
2 3 2
is developed after addition of a few millilitres of K Fe(CN) solution.
4 6
Hydrochloric acid, HCl sp gr 1.19
About 0.5 to 1.0 mL before the true end point is reached, the solution
Hydrofluoric acid, HF 48 %
changes from a blue to a purple color.After the purple color is developed,
Nitric acid, HNO sp gr 1.42
the titration should be continued dropwise to the persistent yellowish
Sulfuric acid, H SO sp gr 1.84
2 4
green end point.
Ammonium hydroxide, NH OH sp gr 0.90
The desired specific gravities or concentrations of all other
7.3 Calculation—Calculate the percent total zinc as ZnO, A,
concentrated acids are stated whenever they are specified.
as follows:
5.3.2 Diluted Acids and Ammonium Hydroxide—
V Z 31.245
Concentrations of diluted acids and ammonium hydroxide, A 5 3100 (1)
F G
S
except when standardized, are specified as a ratio stating the
where:
number of volumes of the concentrated reagents to be diluted
with a given number of volumes of water, as in the following
V =K Fe(CN) solution required for titration of the
2 4 6
example: HCl (1+99) means 1 volume of concentrated HCl (sp
specimen, mL,
gr 1.19) diluted with 99 volumes of water. Z = zinc equivalent of the K Fe(CN) solution, g/mL,
4 6
S = specimen weight, and
6. Preparation of Sample
1.245 = molecular weight ZnO (81.38)/molecular weight Zn
(65.38).
6.1 Grind dry pigments, if lumpy or not finely ground, to a
fine powder for analysis. Large samples may be thoroughly
8. Total Zinc, Using Uranyl Acetate as External Indicator
mixed and a representative portion taken and powdered if
lumpy or not finely ground. Mix the sample in all cases
8.1 Reagents:
thoroughly before taking specimens for analysis.
8.1.1 Uranyl Acetate Indicator Solution (50 g/L)—Dissolve
5gofUO (C H O ) ·2H O in 100 mL of water and make
6.2 Separate pigments from paints or pastes, grind to a fine
2 2 3 2 2 2
slightly acid with acetic acid.
powder, pass through a 180-µm (No. 80) sieve (Note 1)to
8.1.2 Potassium Ferrocyanide, Standard Solution (1
remove any skins, thoroughly mix, and oven dry at 105°C.
Moisten such pigments after weighing with a little alcohol mL = 0.008 g Zn)—Prepare and standardize as in 7.1.2. Run a
blank titration with the same amounts of reagents and water.
before adding reagents for analysis.
Calculate the zinc equivalent of the solution as follows:
Z 5 W/~V 2 B! (2)
Reagent Chemicals, American Chemical Society Specifications, American
Chemical Society, Washington, DC. For suggestions on the testing of reagents not
where:
listed by the American Chemical Society, see Analar Standards for Laboratory
Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
Z = zinc equivalent of the K Fe(CN) solution, g/mL,
4 6
and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,
W = zinc used,
MD.
D3280 − 85 (2009)
10.3 Calculation—Calculate the percent sulfur, A, as fol-
V =K Fe(CN) solution required for titration of the zinc,
4 6
lows:
mL, and
B =K Fe(CN) solution required for titration of the blank,
4 6 P 30.1374
~ !
A 5 3100 (5)
F G
mL.
S
8.2 Procedure:
where:
8.2.1 Weigh to 0.1 mg about 0.4 g of the sample into a
P = BaSO precipitate, g,
tall-form 400-mL beaker. Moisten with about 20 mL of water
S = specimen weight, g, and
and dissolve by adding 10 mL of HCl. Add NH OH until
0.1374 = molecular weight of sulfur (32.064)/molecular
slightly alkaline to litmus paper. Add HCl until just acid, and
weight BaSO (233.43).
thenadd3mLinexcess.Dilutetoabout250mLwithhotwater
and heat nearly to boiling. Titrate with K Fe(CN) solution,
4 6
11. Moisture and Other Volatile Matter
stirring constantly, until a drop of uranyl acetate indicator
11.1 Procedure—Determine moisture and other volatile
tested in a white porcelain spot plate shows a brown tinge after
matter in accordance with Method A of Test Methods D280.
standing 1 min.
8.2.2 Blank—Run a blank titration with the same amounts
LEADED ZINC OXIDE
of reagents and water.
8.3 Calculation—Calculate the percent total zinc as ZnO, A,
12. Tota
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