ASTM D50-90(1999)

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

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:  ASTM Method Refer- Dry Pigments Sections ences Moisture and Other Volatile Matter 6 D 280 Loss on Ignition 7 Coarse Particles 8 D 185 Matter Soluble in Water 9 D 1208 Organic Coloring Matter 10 Iron Oxide 11 and 12 Calcium Compounds (Reported as CaO) 13 and 14 Sulfate Soluble in Hydrochloric Acid 15 and 16 Lead Chromate (in Ochers) 17 Calcium Carbonate (in Venetian Red) 18 C 25 Manganese (in Siennas and Umbers) 19 and 20 Pigment Pastes in Oil Pigment Content 21 D 1208 Moisture and Other Volatile Matter 22 D 1208 Nonvolatile Matter in Vehicle 23 Moisture by Distillation 24 D 1208 Coarse Particles and Skins 25 D 185 Consistency (Stormer) 26 D 562
1.3 This standard does not purport to address the safety problems 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: 09-May-1999
• ICS: 87.060.10 - Pigments and extenders
• Technical Committee: D01 - Paint and Related Coatings, Materials, and Applications
• Drafting Committee: D01.31 - Pigment Specifications

Relations

• Replaced By: ASTM D50-90(2005) - Standard Test Methods for Chemical Analysis of Yellow, Orange, Red, and Brown Pigments Containing Iron and Manganese
• Effective Date: 01-Sep-2005
• Referred By: ASTM D768-01(2019) - Standard Specification for Yellow Iron Oxide Hydrated
• Effective Date: 10-May-1999
• Referred By: ASTM D85-05(2023) - Standard Specification for Ochre Pigment
• Effective Date: 10-May-1999
• Referred By: ASTM D561-82(2020) - Standard Specification for Carbon Black Pigment for Paint
• Effective Date: 10-May-1999
• Referred By: ASTM D49-83(2020) - Standard Test Methods of Chemical Analysis of Red Lead
• Effective Date: 10-May-1999
• Referred By: ASTM D769-01(2019) - Standard Specification for Black Synthetic Iron Oxide
• Effective Date: 10-May-1999
• Referred By: ASTM C979/C979M-16 - Standard Specification for Pigments for Integrally Colored Concrete
• Effective Date: 10-May-1999
• Referred By: ASTM D3721-05(2019) - Standard Specification for Synthetic Red Iron Oxide Pigment
• Effective Date: 10-May-1999
• Referred By: ASTM D763-06(2019) - Standard Specification for Raw and Burnt Umber Pigments
• Effective Date: 10-May-1999
• Referred By: ASTM D3722-05(2019) - Standard Specification for Natural Red and Brown Iron Oxide Pigments
• Effective Date: 10-May-1999
• Referred By: ASTM D765-87(2020) - Standard Specification for Raw and Burnt Sienna Pigments
• Effective Date: 10-May-1999
• Referred By: ASTM D3724-01(2019) - Standard Specification for Synthetic Brown Iron Oxide Pigment
• Effective Date: 10-May-1999

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(Reapproved 1999)
Standard Test Methods for
Chemical Analysis of Yellow, Orange, Red, and Brown
Pigments Containing Iron and Manganese
ThisstandardisissuedunderthefixeddesignationD 50;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginal
adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.Asuperscript
epsilon (e) 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 priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
1.1 These test methods cover procedures for the chemical
analysisofyellow,orange,red,andbrownpigmentscontaining
2. Referenced Documents
iron and manganese. The test methods apply specifically to the
2.1 ASTM Standards:
following pigments: synthetic hydrated yellow iron oxide,
C 25 Test Methods for Chemical Analysis of Limestone,
yellow ocher, red and brown iron oxides, raw and burnt umber,
Quicklime, and Hydrated Lime
raw and burnt sienna, and venetian red.
D 185 Test Methods for Coarse Particles in Pigments,
1.2 The analytical procedures appear in the following order:
Pastes, and Paints
ASTM
D 280 Test Methods for Hygroscopic Moisture (and Other
Method
Refer-
Matter Volatile Under the Test Conditions) in Pigments
Dry Pigments Sections ences
D 562 Test Method for Consistency of Paints Using the
Stormer Viscometer
Moisture and Other Volatile Matter 6 D 280
Loss on Ignition 7
D 1193 Specification for Reagent Water
Coarse Particles 8 D 185
D 1208 Test Methods for Common Properties of Certain
Matter Soluble in Water 9 D 1208
Pigments
Organic Coloring Matter 10
Iron Oxide 11 and 12
E 11 Specification for Wire Cloth Sieves for Testing Pur-
Calcium Compounds (Reported as CaO) 13 and 14
poses
Sulfates Soluble in Hydrochloric Acid 15 and 16
Lead Chromate (in Ochers) 17
3. Significance and Use
Calcium Carbonate (in Venetian Red) 18 C 25
Manganese (in Siennas and Umbers) 19 and 20
3.1 These test methods compile in one place, recommended
procedures for analyzing inorganic colored pigments. These
Pigment Pastes in Oil
pigments are used extensively in paints, and for this reason
Pigment Content 21 D 1208
their compositions are important to the formulators and user.
Moisture and Other Volatile Matter 22 D 1208
Nonvolatile Matter in Vehicle 23
4. Preparation of Sample
Moisture by Distillation 24 D 1208
Coarse Particles and Skins 25 D 185
4.1 Mix the sample thoroughly and take a representative
Consistency (Stormer) 26 D 562
portion for analysis. Reduce any lumps or coarse particles to a
1.3 This standard does not purport to address all of the
fine powder by grinding. Grind extracted pigments to pass a
safety concerns, if any, associated with its use. It is the
No. 80 (180-µm) sieve (see Specification E 11 for detailed
responsibility of the user of this standard to establish appro-
1 2
ThesetestmethodsareunderthejurisdictionofASTMCommitteeD-1onPaint Annual Book of ASTM Standards, Vol 04.01.
and Related Coatings, Materials, and Applications and are the direct responsibility Annual Book of ASTM Standards, Vol 06.03.
of Subcommittee D01.31 on Pigment Specification. Annual Book of ASTM Standards, Vol 06.01.
Current edition approved May 25, 1990. Published July 1990. Originally Annual Book of ASTM Standards, Vol 11.01.
published as D 50 – 17 T. Last previous edition D 50 – 81. Annual Book of ASTM Standards, Vol 14.02.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D50
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 D 1193. 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 mLof 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 D 280.
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 Bureau of Standards
oxide (SO ) if much calcium sulfate (CaSO ) is present. The
3 4 standard sample No. 27 of Sibley iron ore.
CO may be determined on a separate portion if desired.
11.6 Potassium Ferricyanide Solution (K Fe(CN) )—A
3 6
very dilute solution is most satisfactory. Dissolve approxi-
NOTE 1—It is inadvisable to use platinum unless it is known that
mately 0.01 g of K Fe(CN) in 50 mL of water. This solution
attacking substances are absent.
3 6
must be made fresh when wanted 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
Method D 185.
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
9.1 Determine matter soluble in water in accordance with of a few drops of SnCl solution after adding the acid greatly
assistsdissolvingoftheiron.Whentheresidueislightincolor,
Test Methods D 1208.
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
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 5 CaO equivalent of the KMnO solution, g/mL,
white precipitate should form. If none, or a heavy grayish
W 5 sodium oxalate used, g, and
precipitate forms, the determination should be discarded and 1
V 5 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
...