ASTM D50-90(2005)

Standard Test Methods for Chemical Analysis of Yellow, Orange, Red, and Brown Pigments Containing Iron and Manganese

SIGNIFICANCE AND USE
These test methods compile in one place, recommended procedures for analyzing inorganic colored pigments. These pigments are used extensively in paints, and for this reason their compositions are important to the formulators and user.
SCOPE
1.1 These test methods cover procedures for the chemical analysis of yellow, orange, red, and brown pigments containing iron and manganese. The test methods apply specifically to the following pigments: synthetic hydrated yellow iron oxide, yellow ocher, red and brown iron oxides, raw and burnt umber, raw and burnt sienna, and venetian red.
1.2 The analytical procedures appear in the following order:ASTMMethodRefer-Dry PigmentsSections encesMoisture and Other Volatile MatterD 280Loss on IgnitionCoarse Particles D 185Matter Soluble in WaterD 1208Organic Coloring MatterIron Oxide and Calcium Compounds (Reported as CaO) and Sulfates Soluble in Hydrochloric Acid and Lead Chromate (in Ochers)Calcium Carbonate (in Venetian Red)C 25Manganese (in Siennas and Umbers) and Pigment Pastes in OilPigment Content D 1208Moisture and Other Volatile MatterD 1208Nonvolatile Matter in VehicleMoisture by Distillation D 1208Coarse Particles and Skins D 185Consistency (Stormer) D 562
1.3 &solely-SI-units;
1.4 This standard does not purport to address all of the safety concerns, if any, 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 D50-90(1999) - Standard Test Methods for Chemical Analysis of Yellow, Orange, Red, and Brown Pigments Containing Iron and Manganese
• Effective Date: 01-Sep-2005
• Replaced By: ASTM D50-90(2011) - Standard Test Methods for Chemical Analysis of Yellow, Orange, Red, and Brown Pigments Containing Iron and Manganese
• Effective Date: 01-Jun-2011
• Referred By: ASTM D49-83(2020) - Standard Test Methods of Chemical Analysis of Red Lead
• Effective Date: 01-Sep-2005
• Referred By: ASTM D769-01(2019) - Standard Specification for Black Synthetic Iron Oxide
• Effective Date: 01-Sep-2005
• Referred By: ASTM D3721-05(2019) - Standard Specification for Synthetic Red Iron Oxide Pigment
• Effective Date: 01-Sep-2005
• Referred By: ASTM D85-05(2023) - Standard Specification for Ochre Pigment
• Effective Date: 01-Sep-2005
• Referred By: ASTM D763-06(2019) - Standard Specification for Raw and Burnt Umber Pigments
• Effective Date: 01-Sep-2005
• Referred By: ASTM D765-87(2020) - Standard Specification for Raw and Burnt Sienna Pigments
• Effective Date: 01-Sep-2005
• Referred By: ASTM D3722-05(2019) - Standard Specification for Natural Red and Brown Iron Oxide Pigments
• Effective Date: 01-Sep-2005
• Referred By: ASTM D561-82(2020) - Standard Specification for Carbon Black Pigment for Paint
• Effective Date: 01-Sep-2005
• Referred By: ASTM C979/C979M-16 - Standard Specification for Pigments for Integrally Colored Concrete
• Effective Date: 01-Sep-2005
• Referred By: ASTM D3724-01(2019) - Standard Specification for Synthetic Brown Iron Oxide Pigment
• Effective Date: 01-Sep-2005
• Referred By: ASTM D768-01(2019) - Standard Specification for Yellow Iron Oxide Hydrated
• 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:D50–90(Reapproved2005)
Standard Test Methods for
Chemical Analysis of Yellow, Orange, Red, and Brown
Pigments Containing Iron and Manganese
ThisstandardisissuedunderthefixeddesignationD50;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginal
adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.Asuperscript
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 1.4 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
1.1 These test methods cover procedures for the chemical
responsibility of the user of this standard to establish appro-
analysisofyellow,orange,red,andbrownpigmentscontaining
priate safety and health practices and determine the applica-
iron and manganese. The test methods apply specifically to the
bility of regulatory limitations prior to use.
following pigments: synthetic hydrated yellow iron oxide,
yellow ocher, red and brown iron oxides, raw and burnt umber,
2. Referenced Documents
raw and burnt sienna, and venetian red.
2.1 ASTM Standards:
1.2 The analytical procedures appear in the following order:
C25 Test Methods for Chemical Analysis of Limestone,
ASTM
Quicklime, and Hydrated Lime
Method
Refer-
D185 Test Methods for Coarse Particles in Pigments
Dry Pigments Sections ences
D280 Test Methods for Hygroscopic Moisture (and Other
Matter Volatile Under the Test Conditions) in Pigments
Moisture and Other Volatile Matter 6 D280
Loss on Ignition 7
D562 Test Method for Consistency of Paints Measuring
Coarse Particles 8 D185
Krebs Unit (KU)Viscosity Using a Stormer-TypeViscom-
Matter Soluble in Water 9 D1208
eter
Organic Coloring Matter 10
Iron Oxide 11 and 12
D1193 Specification for Reagent Water
Calcium Compounds (Reported as CaO) 13 and 14
D1208 Test Methods for Common Properties of Certain
Sulfates Soluble in Hydrochloric Acid 15 and 16
Pigments
Lead Chromate (in Ochers) 17
Calcium Carbonate (in Venetian Red) 18 C25
E11 SpecificationforWovenWireTestSieveClothandTest
Manganese (in Siennas and Umbers) 19 and 20
Sieves
Pigment Pastes in Oil
3. Significance and Use
Pigment Content 21 D1208
3.1 These test methods compile in one place, recommended
Moisture and Other Volatile Matter 22 D1208
procedures for analyzing inorganic colored pigments. These
Nonvolatile Matter in Vehicle 23
Moisture by Distillation 24 D1208
pigments are used extensively in paints, and for this reason
Coarse Particles and Skins 25 D185
their compositions are important to the formulators and user.
Consistency (Stormer) 26 D562
1.3 The values stated in SI units are to be regarded as 4. Preparation of Sample
standard. No other units of measurement are included in this
4.1 Mix the sample thoroughly and take a representative
standard.
portion for analysis. Reduce any lumps or coarse particles to a
fine powder by grinding. Grind extracted pigments to pass a
No. 80 (180-µm) sieve (see Specification E11 for detailed
These test methods are under the jurisdiction of ASTM Committee D01 on
Paint and Related Coatings, Materials, and Applications and are the direct
responsibility of Subcommittee D01.31 on Pigment Specification. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Sept. 1, 2005. Published September 2005. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approvedin1917.Lastpreviouseditionapprovedin1999asD50 – 90 (1999).DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/D0050-90R05. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D50–90 (2005)
requirements). Discard any skins that do not pass through the with 25 mL of 1 N alcoholic sodium hydroxide (NaOH)
sieve. Mix the finely ground pigment thoroughly. solution and again decant. Boil another 2-g portion of the
sample with 25 mL of chloroform, let settle, and decant the
5. Purity of Reagents
supernatant liquid. If any one of the above solutions is colored,
5.1 Purity of Reagents—Unless otherwise indicated, it is
organic coloring matter is indicated (Note 2). If the solutions
intended that all reagents shall conform to the specifications of
remain colorless, organic colors are probably absent, but may
theCommitteeonAnalyticalReagentsoftheAmericanChemi-
be tested for by reference to procedures given in standard
cal Society, where such specifications are available. Other
reference works, taking into account the nature of the pigment
grades may be used, provided it is first ascertained that the
involved.
reagent is of sufficiently high purity to permit its use without
NOTE 2—With this class of pigments indication of presence of an
lessening the accuracy of the determination.
organic color may often be noted by the characteristic odor given off on
5.2 Purity of Water—Unless otherwise indicated, references
ignition.
to water shall be understood to mean Type II reagent water
conforming to Specification D1193. Iron Oxide
DRY PIGMENTS
11. Reagents
Moisture and Other Volatile Matter
11.1 Stannous Chloride Solution (SnCl ·2H O)—Dissolve
2 2
50 g of SnCl ·2H O in 300 mL of hydrochloric acid (HCl) (sp
6. Procedure
2 2
gr 1.19) and dilute with water to 500 mL. Keep the clear
6.1 Determine moisture and other volatile matter in accor-
solution in a tightly stoppered bottle containing some metallic
dance with Method A of Test Methods D280.
tin.
Loss on Ignition 11.2 Mercuric Chloride Solution (HgCl )—Prepare a satu-
rated solution of HgCl (60 to 100 g/L).
7. Procedure
11.3 Sulfuric-Phosphoric Acid Mixture—Mix 150 mL of
7.1 Weigh accurately approximately1gof pigment into a
sulfuric acid (H SO ) (sp gr 1.84) with 150 mL of phosphoric
2 4
previously weighed and ignited porcelain crucible (Note 1).
acid (H PO ) (85 %) and dilute with water to 1 L.
3 4
Cover and ignite to constant weight over a bunsen or Meker
11.4 Diphenylamine Indicator—Dissolve1gof dipheny-
burner or in an electric furnace at a temperature of approxi-
lamine in 100 mL of H SO (sp gr 1.84).
2 4
mately 900°C. Cool in a desiccator, weigh, and calculate the
11.5 Standard Potassium Dichromate Solution—(K Cr O )
2 2 7
percent loss on ignition. This figure may include combined
(0.1 N)—Dissolve 4.904 g of K Cr O in water and dilute to 1
2 2 7
water, carbon dioxide (CO ), organic matter, and some sulfuric
L. Standardize against the National Institute of Standards and
oxide (SO ) if much calcium sulfate (CaSO ) is present. The
Technology standard sample No. 27 of Sibley iron ore.
3 4
CO may be determined on a separate portion if desired.
11.6 Potassium Ferricyanide Solution (K Fe(CN) )—
3 6
Optional. Dissolve approximately 0.01 g of K Fe(CN) in 50
3 6
NOTE 1—It is inadvisable to use platinum unless it is known that
mL of water. This solution must be made fresh when wanted
attacking substances are absent.
because it does not keep.
Coarse Particles
12. Procedure
8. Procedure
12.1 According to the amount of iron in the pigment, weigh
8.1 Determine coarse particles in accordance with Test
0.3 to 1.0 g of the pigment and ignite in a porcelain crucible at
Methods D185.
a dull red heat to destroy organic matter. Transfer to a 400-mL
beaker and add 25 mL of HCl (sp gr 1.19). Cover with a
Matter Soluble in Water
watchglassanddigestjustshortofboiling(80to90°C)untilno
9. Procedure
dark specks can be seen in the insoluble residue. The addition
of a few drops of SnCl solution after adding the acid greatly
9.1 Determine matter soluble in water in accordance with
assistsdissolvingoftheiron.Whentheresidueislightincolor,
Test Methods D1208.
thesolutionofironmaybeconsideredcomplete.Thismaytake
Organic Coloring Matter
from 15 min to 1 h, or longer.
12.2 Add 25 to 50 mL of water and heat to gentle boiling
10. Procedure
(avoid vigorous prolonged boiling). Slowly add SnCl solution
10.1 Boil2gofthe sample with 25 mL of water, let settle,
dropwiseuntilthelastdropmakesthesolutioncolorlessorfree
and decant the supernatant liquid. Boil the residue with 25 mL
from any tinge of yellow, then add 1 or 2 drops in excess. It is
of ethyl alcohol (95 %) and decant as before. Boil the residue
best to keep the watchglass on the beaker while adding the
SnCl solution,withagitationofthehotironsolutionaftereach
Reagent Chemicals, American Chemical Society Specifications, American
addition.IftoomuchSnCl isaddedbymistake,addpotassium
Chemical Society, Washington, DC. For suggestions on the testing of reagents not
listed by the American Chemical Society, see Analar Standards for Laboratory
Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, Reference may be made to the following: Payne, H. F., “Organic Coatings
MD. Technology,” Vol II, John Wiley & Sons, Inc., New York, N. Y., 1961.
D50–90 (2005)
permanganate (KMnO ) to the solution until a yellow color 13.4 Calculate the calcium oxide (CaO) value of the solu-
appears, then again add SnCl dropwise until the yellow color tion as follows:
justdisappears,againaddingoneortwodropsinexcess.Dilute
C 5 ~W 3 V ! 3 0.4185 (2)
1 1
with 200 mL of cold water; then add all at once with vigorous
stirring 15 mLof HgCl solution. Let stand 3 to 4 min.Aslight where:
C = CaO equivalent of the KMnO solution, g/mL,
white precipitate should form. If none, or a heavy grayish
W = sodium oxalate used, g, and
precipitate forms, the determination should be discarded and 1
V = KMnO solution required for the titration, mL.
1 4
repeated.
12.3 Add 15 mL of H SO -H PO mixture and 3 drops of 0.4185 5 CaO/Na C O 5 56.08 / 134.01 (3)
2 4 3 4 2 2 4
diphenylamine indicator solution. Titrate with K Cr O solu-
2 2 7
14. Procedure
tion, taking the sudden change of the dark green color to a
blue-black color as the end point.
14.1 Weigh 2.5 g of sample, transfer to a porcelain crucible,
12.4 If preferred, K Fe(CN) may be used as an external
and ignite at a dull red heat to destroy organic matter. Cool,
3 6
indicator. In this case omit the addition of the H SO -H PO
transfer to a 600-mL beaker, and add 100 mL of HCl (1 + 1).
2 4 3 4
mixture and the diphenylamine indicator. Titrate with the
Digest just short of boiling until no dark specks can be seen in
K Cr O solution as in 12.3, except toward the end take out a
the insoluble residue.Add ammonium hydroxide (NH OH) (sp
2 2 7
very small drop of the solution being titrated and touch thi
...