ASTM C471M-14

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Designation: C471M − 14
StandardTest Methods for
Chemical Analysis of Gypsum and Gypsum Products
(Metric)
This standard is issued under the fixed designation C471M; 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* 1.4 The values stated in SI units are to be regarded as the
standard.
1.1 These test methods cover the chemical analysis of
1.5 This standard does not purport to address all of the
gypsum and gypsum panel products, including gypsum ready-
safety concerns, if any, associated with its use. It is the
mixed plaster, gypsum wood-fibered plaster, and gypsum
responsibility of the user of this standard to establish appro-
concrete.
priate safety and health practices and determine the applica-
1.2 The test methods appear in the following order:
bility of regulatory limitations prior to use.
Sections
Preparation of Sample 4
2. Referenced Documents
Complete Procedure 5–16
Alternative Procedure for Analysis for
2.1 ASTM Standards:
Calcium Sulfate by Ammonium Acetate 17–22
C11 Terminology Relating to Gypsum and Related Building
Method
Alternative Procedure for Analysis for Materials and Systems
Sodium Chloride by the Coulometric 23–29
C22/C22M Specification for Gypsum
Method
C28/C28M Specification for Gypsum Plasters
Determination of Sand in Set Plaster 30–36
Wood-Fiber Content in Wood-Fiber Gyp- 37–39
C59 Specification for Gypsum Casting Plaster and Gypsum
sum Plaster
Molding Plaster
Optional Procedure for Analysis for So-
C61 Specification for Gypsum Keene’s Cement
dium by the Atomic Absorption Method 40–46
Optional Procedure for Analysis for So- 47–54
C317/C317M Specification for Gypsum Concrete
dium by Flame Photometry
C778 Specification for Standard Sand
Determination of Orthorhombic Cyclooc- 55
C842 Specification forApplication of Interior Gypsum Plas-
tasulfur (S ) in Ggypsum Panel
Products—General Provisions
ter
Determination of Orthorhombic Cyclooc- 56
D1193 Specification for Reagent Water
tasulfur (S ) in Gypsum Panel Prod-
D1428 Test Method for Test for Sodium and Potassium In
ucts by Gas Chromatograph Equipped
with a Mass Spectrometer (GS/MS)
Water and Water-Formed Deposits by Flame Photometry
Determination of Orthorhombic Cyclooc- 57 3
(Withdrawn 1989)
tasulfur (S ) in Gypsum Panel Prod-
D2013 Practice for Preparing Coal Samples for Analysis
ucts by Gas Chromatograph Equipped
with an Electron Capture Detector
E11 Specification for Woven Wire Test Sieve Cloth and Test
(GC/ECD)
Sieves
Determination of Orthorhombic Cyclooc- 58
tasulfur (S ) in Gypsum Panel Prod-
ucts by High-performance Liquid Chro- 3. Terminology
matograph Equipped with and
3.1 Definitions—Definitions shall be in accordance with
Ultraviolet Detector (HPLC/UV)
Terminology C11.
1.3 The text of this standard references notes and footnotes
3.2 Definitions of Terms Specific to This Standard:
that provide explanatory material. These notes and footnotes
3.2.1 calibration standard, n—a chemical mixture contain-
(excluding those in tables and figures) shall not be considered
ing a known quantity of the analyte used to relate the measured
as requirements of the standard.
analytical signal to the concentration of the analyte.
These test methods are under the jurisdiction of ASTM Committee C11 on
Gypsum and Related Building Materials and Systems and are the direct responsi- For referenced ASTM standards, visit the ASTM website, www.astm.org, or
bility of Subcommittee C11.01 on Specifications and Test Methods for Gypsum contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Products. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved Nov. 1, 2014. Published November 2014. Originally the ASTM website.
approved in 1961. Last previous edition approved in 2013 as C471 – 13. DOI: The last approved version of this historical standard is referenced on
10.1520/C0471M-14. www.astm.org.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C471M − 14
3.2.2 dried sample, n—a sample devoid of free water. 4.4 Gypsum Casting and Molding Plaster,(C59)—Reduce
the dried sample in accordance with 4.1.5. Thoroughly blend
3.2.3 internal standard, n—a chemical used in the quantifi-
and rehydrate the specimen in accordance with 4.1.4.
cationofS bymonitoringandadjustingforminorvariancesin
instrument performance.
4.5 Gypsum Keene’s Cement,(C61)—Reduce the dried
sample in accordance with 4.1.5. Blend in no more than 1 %
3.2.4 riffle, n—a hand feed sample divider device that
molding plaster or K SO and rehydrate the specimen in
divides the sample into parts of approximately the same 2 4
accordance with 4.1.4.
weight. (D2013)
4.6 Gypsum Concrete,(C317/C317M)—Screen the dried
3.2.5 sample as received, n—a representative portion of raw
sample through a 150-µm (No. 100) sieve and discard the
gypsum or gypsum product in the state received by the testing
residue retained on the sieve. Reweigh the remaining sample
laboratory, including aggregates, impurities and water content.
and calculate the percentage of the dried sample. Reduce the
3.2.6 surrogate standard, n—a chemical used to account for
sample in accordance with 4.1.5. Thoroughly blend and rehy-
extraction efficiency of S .
drate the specimen in accordance with 4.1.4.
4. Preparation of Sample
4.7 Gypsum Panel Products—Cut or break the dried sample
4.1 General Procedures—Details of sample preparation will
into small pieces. Using a mortar and pestle, strike the pieces
vary according to the type of material being tested. of the sample to loosen the paper face. Remove the pieces of
4.1.1 Sample As Received—Use a sufficient amount of
paper by hand as they are separated from the core of the
sample such that, after sieving, not less than 50 g of sample gypsum board. Carefully scrape any remaining powder from
will remain for testing. Weigh the entire sample immediately
the paper. When all the paper has been removed from the
after opening the container in which the material was received. pieces of the sample, reduce the sample in accordance with
This will become the weight of the sample as received.
4.1.5.
4.1.2 Drying—DrythesampleinaccordancewithSection7.
COMPLETE PROCEDURE
This will be the weight of the dried sample.
4.1.3 Crushing and Grinding—Crush and grind the sample
5. Apparatus
by hand with a mortar and pestle or by mechanical crushing
and grinding equipment to pass a 250-µm (No. 60) sieve. Take 5.1 Analytical Balance—Capable of weighing the weighing
care,particularlywithmechanicalequipment,nottoexposethe bottles, lids and samples.
sample to temperatures of more than 52°C. Clean the equip-
5.2 Balance—Capable of weighing not less than 100 g at a
ment thoroughly between samples. Thoroughly remix the
precision of 0.001 g.
ground sample and store it in an airtight container to avoid
5.3 Drying Oven—A mechanical convection oven set at 45
contamination.
6 3°C.
4.1.4 Rehydrating—Thoroughly blend and rehydrate
samples which contain calcium sulfate in forms other than
5.4 Desiccator—Capable of being tightly sealed and con-
CaSO ·2H O and natural anhydrite. Place the sample in
taining calcium chloride or equivalent desiccant.
4 2
distilled water and keep it wet for not less than 48 h. Dry the
5.5 Calcining Oven or Furnace—Capable of achieving and
hydratedsampleinanovenat45 63°Ctoconstantweightand
maintaining temperatures to not less than 1000°C.
recrush or grind it in accordance with 4.1.3.
5.6 Weighing Bottles—Borosilicate glass or ceramic con-
4.1.5 Sample Reduction—Thoroughly mix and reduce large
tainers with tightly sealable lids.
samples as required by quartering or by the use of a riffle to
obtain a specimen of approximately 50 g.
5.7 Hot Plate—A controllable hot plate capable of heating
casseroles to approximately 120°C.
4.2 Gypsum (C22/C22M)—Gypsum samples will be re-
ceived in the form of rocks or powder, or both. If necessary
5.8 Porcelain Casseroles—Withacapacityof50to100mL.
crush and reduce the entire dried sample in accordance with
5.9 Filtering Funnels.
4.1.3 and 4.1.5.
5.10 Filter Paper.
4.3 Gypsum Plaster, (C28/C28M).
5.11 Porcelain Crucibles.
4.3.1 Gypsum Ready-Mixed Plaster or Gypsum WoodFi-
bered Plaster—Screen the dried sample through a 150-µm
5.12 Mortar and Pestle.
(No. 100) sieve and discard the residue retained on the sieve.
5.13 Mechanical Jaw Crusher—Capable of crushing gyp-
Reweigh the remaining sample and calculate the percentage of
sum rocks up to 50 mm diameter.
the dried sample. Reduce the sample in accordance with 4.1.5.
5.14 Mechanical Grinder—Burr mill or equivalent capable
Thoroughly blend and rehydrate the specimen in accordance
of grinding the granular output of the jaw crusher specified in
with 4.1.4.
5.13.
4.3.2 Gypsum Neat Plaster or Gypsum Gauging Plaster—
Reduce the dried sample in accordance with 4.1.5. Thoroughly
6. Reagents
blend and rehydrate the specimen in accordance with 4.1.4.
6.1 Purity of Reagents—Use reagent grade chemicals in all
Detailed requirements for this sieve are given in Specification E11. tests. Unless otherwise indicated, use reagents that conform to
C471M − 14
the specifications of the Committee on Analytical Reagents of 7. Free Water
the American Chemical Society, where such specifications are
7.1 Significance and Use—The free water analysis deter-
available. If it is necessary to use other grades, first ascertain
mines the amount of free water contained in the sample as
that the reagent is of sufficiently high purity so that its use will
opposed to chemically combined water, and prepares the
not lessen the accuracy of the determination.
sample for further analysis.
6.1.1 Ammonium Chloride (NH Cl).
7.2 Procedure:
6.1.2 Ammonium Hydroxide (sp gr 0.90)—Concentrated
7.2.1 Weigh a sample of the material as received of not less
ammonium hydroxide (NH OH).
6.1.3 Ammonium Nitrate (25 g/L)—Dissolve 25 g of ammo- than 50 g to a precision of 0.001 g and spread it out in a thin
layer in a suitable vessel. Place in an oven and dry at 45 6 3°C
nium nitrate (NH NO ) in water and dilute to 1 L.
4 3
6.1.4 Ammonium Oxalate ((NH ) C O ). for 2 h, then cool in a desiccator and weigh again. The loss of
4 2 2 4
weight corresponds to the free water.
6.1.5 BariumChloride(100g/L)—Dissolve100gofbarium
chloride (BaCl ·2H O) in water and dilute to 1 L.
7.2.2 Retain the sample in a sealed container or in the
2 2
6.1.6 Calcium Chloride (CaCl )—Anhydrous Calcium desiccator for further analysis.
Chloride with a combined water of not more than 5 %.
7.3 Calculation and Report—Calculate and report loss in
6.1.7 Hydrochloric Acid (sp gr 1.19)—Concentrated hydro-
weightasapercentageofthesampleasreceivedorofthedried
chloric acid (HCl).
sample as required.
6.1.8 Hydrochloric Acid(1+4)—Mix 1 volume of HCl (sp
7.4 Precision and Bias—Neither the precision nor the bias
gr 1.19) with 4 volumes of water.
6.1.9 Hydrochloric Acid(1+5)—Mix 1 volume of HCl (sp for the free water analysis has been determined.
gr 1.19) with 5 volumes of water.
6.1.10 Nitric Acid (sp gr 1.42)—Concentrated nitric acid 8. Combined Water
(HNO ).
8.1 Significance and Use—The combined water analysis
6.1.11 Potassium Chromate Solution (100 g/L)—Dissolve
determines the percent of chemically combined water and is
5 g of potassium chromate (K CrO ) in 50 mL of water, mix,
2 4
used to calculate the purity of gypsum or the amount of
add 10 drops of 0.05 N silver nitrate (AgNO ) solution, allow
gypsum or gypsum plaster in gypsum products.
to stand for 5 min, and filter.
8.2 Interferences—Some materials, such as organic and
6.1.12 Potassium Permanganate (5.6339 g/L)—Dissolve
hydrated compounds that decompose within the same tempera-
5.6339 g of potassium permanganate (KMnO ) in water and
ture range as gypsum, will cause high results. When the
dilute to 1 L.
maximum temperature is exceeded, some carbonates undergo
6.1.13 Silver Nitrate, Standard Solution (0.05 N)—Prepare
decomposition, which will result in high results.
and standardize a 0.05 N silver nitrate (AgNO ) solution.
6.1.14 Sodium Ammonium Phosphate—(NaNH HPO ).
4 4
8.3 Procedure:
6.1.15 Sulfuric Acid (sp gr 1.84)—Concentrated sulfuric
8.3.1 For each sample, place three weighing bottles with
acid (H SO ).
2 4
lids in the preheated calcining oven or furnace and heat for 2 h
6.1.16 Sulfuric Acid (1+6)—Carefully mix 1 volume of
at 215 to 230°C. Place in the desiccator and allow to cool to
H SO (sp gr 1.84) with 6 volumes of water.
2 4
room temperature. Weigh the bottles and lids to the nearest
6.1.17 Nitric Acid (0.1 N)—Mix 1.4 mL of HNO (sp gr
0.0001 g and record the tare weights.
1.42) with 200 mL of water.
8.3.2 Weigh out three specimens of approximately 1 g each
6.1.18 Phenolphthalein Indicator Solution—Dissolve0.25 g
of the sample as prepared in Section 4 and dried in Section 7
of phenolphthalein in 30 mL of methanol and dilute to 50 mL
to a precision of 0.0001 g in the previously tared weighing
with water.
bottles and record the total weight with lids.
6.1.19 Sodium Hydroxide Solution (0.1 N)—Dissolve1gof
8.3.3 Place the specimens in the calcining oven with the lids
sodium hydroxide (NaOH) in 250 mL of water.
placed loosely on each bottle or crucible for2hor until
6.1.20 Water—Reagent water shall be in accordance with
constant weight has been obtained.
Specification D1193, type II. Specification D1193 gives the
8.3.4 Place the lids tightly on the weighing bottles, remove
following values for type II grade water.
from the oven, and place in the desiccator to cool to room
Electrical conductivity, max, µS/cm at 298 K (25-C) 1.0
temperature.
Electrical resistivity, min, MΩ·cm at 298 K (25-C) 1.0
Total organic carbon (TOC), max, µg/L 50.0
8.3.5 Weigh each specimen to a precision of 0.0001 g and
Sodium, max, µg/L 5.0
record the weights.
Chlorides max, µg/L 5.0
Total silica, max, µg/L 5.0
8.3.6 Retain the residues for carbon dioxide analysis.
8.4 Calculation and Report—Calculate and report the aver-
age loss in weight of the three specimens as a percentage of the
Reagent Chemicals, American Chemical Society Specifications , American
sample as received or of the dried sample, as required, to the
Chemical Society, Washington, DC. For suggestions on the testing of reagents not
nearest 0.001 g and record the tare weights.
listed by the American Chemical Society, see Analar Standards for Laboratory
Chemicals, BDH Ltd., Poole, Dorset, U.K., and t
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