ASTM E351-18

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: E351 − 18
Standard Test Methods for
Chemical Analysis of Cast Iron—All Types
This standard is issued under the fixed designation E351; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber 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 U.S. Department of Defense.
1. Scope
Cerium and Lanthanum by the Direct Current Plasma Atomic
Emission Spectrometry Method (Ce: 0.003 % to 0.5 %; La: 0.001
1.1 These test methods cover the chemical analysis of pig
% to 0.30 %) 237–245
Chromium by the Atomic Absorption Method (0.006 % to 1.00 %) 208–217
iron, gray cast iron (including alloy and austenitic), white cast
Chromium by the Peroxydisulfate Oxidation—Titration Method (0.05
iron, malleable cast iron, and ductile (nodular) iron having
% to 30.0 %) 218–226
chemical compositions within the following limits:
Chromium by the Peroxydisulfate-Oxidation Titrimetric Method (0.05
%to30.0%)—Discontinued 1980 144–151
Element Composition Range, %
Cobalt by the Ion-Exchange—Potentiometric Titration Method (2.0 %
to 4.5 %) 53–60
Aluminum 0.003 to 0.50
Cobalt by the Nitroso-R-Salt Spectrophotometric Method (0.01 % to
Antimony 0.005 to 0.03
4.50 %) 61–70
Arsenic 0.02 to 0.10
Copper by the Neocuproine Spectrophotometric Method (0.03 % to
Bismuth 0.001 to 0.03
7.5 %) 116–125
Boron 0.001 to 0.10
Copper by the Sulfide Precipitation-Electrodeposition Gravimetric
Cadmium 0.001 to 0.005
Method (0.03 % to 7.5 %) 81–88
Carbon 1.25 to 4.50
Lead by the Ion-Exchange—Atomic Absorption Spectrometry
Cerium 0.005 to 0.05
Method (0.001 % to 0.15 %) 126–135
Chromium 0.01 to 30.00
Magnesium by the Atomic Absorption Spectrometry Method (0.002
Cobalt 0.01 to 4.50
% to 0.10 %) 71–80
Copper 0.03 to 7.50
Manganese by the Periodate Spectrophotometric Method (0.10 % to
Lead 0.001 to 0.15
2.00 %) 9–18
Magnesium 0.002 to 0.10
Manganese by the Peroxydisulfate-Arsenite Titrimetric Method (0.10
Manganese 0.06 to 2.50
% to 3.5 %) 152–159
Molybdenum 0.01 to 5.00
Molybdenum by the Ion Exchange–8-Hydroxyquinoline Gravimetric
Nickel 0.01 to 36.00
Method 257–264
Phosphorus 0.01 to 0.90
Molybdenum by the Thiocyanate Spectrophotometric Method (0.01
Selenium 0.001 to 0.06
% to 1.5 %) 196–207
Silicon 0.10 to 6.0
Nickel by the Dimethylglyoxime Gravimetric Method (0.1 % to 36.00
Sulfur 0.005 to 0.25
%) 168–175
Tellurium 0.001 to 0.35
Nickel by the Ion Exchange-Atomic Absorption Spectrometry Method
Tin 0.001 to 0.35
(0.005 % to 1.00 %) 176–185
Titanium 0.001 to 0.20
Phosphorus by the Alkalimetric Method (0.02 % to 0.90 %) 160–167
Tungsten 0.001 to 0.20
Phosphorus by the Molybdenum Blue Spectrophotometric Method
Vanadium 0.005 to 0.50
(0.02 % to 0.90 %) 19–30
Zinc 0.005 to 0.20
Silicon by the Gravimetric Method (0.1 % to 6.0 %) 46–52
1.2 The test methods in this standard are contained in the Sulfur by the Gravimetric Method—Discontinued 1988 30–36
Sulfur by the Combustion-Iodate Titration Method (0.005 % to
sections indicated below:
0.25 %)—Discontinued 2012 37–45
Sections Sulfur by the Chromatographic Gravimetric Method—Discontinued
1980 136–143
Carbon, Graphitic, by the Direct Combustion Infrared Absorption Tin by the Solvent Extraction-Atomic Absorption Spectrometry
Method (1 % to 3 %) 108–115 Method (0.002 % to 0.10 %) 186–195
Carbon, Total by the Combustion Gravimetric Method (1.25 % to Tin by the Sulfide Precipitation-Iodometric Titration Method (0.01 %
4.50 %)—Discontinued 2012 97–107 to 0.35 %) 89–96
Titanium by the Diantipyrylmethane Spectrophotometric Method
(0.006 % to 0.35 %) 246–256
Vanadium by the Atomic Absorption Spectrometry Method (0.006 %
These test methods are under the jurisdiction of ASTM Committee E01 on
to 0.15 %) 227–236
Analytical Chemistry for Metals, Ores, and Related Materials and are the direct
responsibility of Subcommittee E01.01 on Iron, Steel, and Ferroalloys.
1.3 Procedures for the determination of carbon and sulfur
Current edition approved July 1, 2018. Published September 2018. Originally
not included in these test methods can be found in Test
approved in 1968. Last previous edition approved in 2013 as E351–13. DOI:
Methods E1019.
10.1520/E0351-18.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E351 − 18
1.4 Some of the composition ranges given in 1.1 are too Nitrogen, and Oxygen in Steel, Iron, Nickel, and Cobalt
broad to be covered by a single method and therefore this Alloys by Various Combustion and Inert Gas Fusion
standard contains multiple methods for some elements. The Techniques
user must select the proper method by matching the informa- E1024Guide for Chemical Analysis of Metals and Metal
tion given in the Scope and Interference sections of each Bearing Ores by Flame Atomic Absorption Spectropho-
method with the composition of the alloy to be analyzed. tometry (Withdrawn 2004)
E1601Practice for Conducting an Interlaboratory Study to
1.5 The values stated in SI units are to be regarded as
Evaluate the Performance of an Analytical Method
standard.
E1806Practice for Sampling Steel and Iron for Determina-
1.6 This standard does not purport to address all of the
tion of Chemical Composition
safety concerns, if any, associated with its use. It is the
2.2 Other Document:
responsibility of the user of this standard to establish appro-
ISO 5725Precision of Test Methods—Determination of
priate safety, health, and environmental practices and deter-
Repeatability and Reproducibility for Inter-Laboratory
mine the applicability of regulatory limitations prior to use.
Tests
Specific hazards statements are given in Section 6 and in
special “Warning” paragraphs throughout these Methods.
3. Terminology
1.7 This international standard was developed in accor-
3.1 Fordefinitionsoftermsusedinthesetestmethods,refer
dance with internationally recognized principles on standard-
to Terminology E135.
ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom-
4. Significance and Use
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee. 4.1 These test methods for the chemical analysis of metals
and alloys are primarily intended as referee methods to test
2. Referenced Documents
such materials for compliance with compositional
specifications, particularly those under the jurisdiction of
2.1 ASTM Standards:
ASTM CommitteeA04 on Iron Castings. It is assumed that all
D1193Specification for Reagent Water
who use these test methods will be trained analysts capable of
E29Practice for Using Significant Digits in Test Data to
performing common laboratory procedures skillfully and
Determine Conformance with Specifications
safely. It is expected that work will be performed in a properly
E50Practices for Apparatus, Reagents, and Safety Consid-
equippedlaboratoryunderappropriatequalitycontrolpractices
erations for Chemical Analysis of Metals, Ores, and
such as those described in Guide E882.
Related Materials
E60Practice for Analysis of Metals, Ores, and Related
5. Apparatus, Reagents, and Instrumental Practices
Materials by Spectrophotometry
E135Terminology Relating to Analytical Chemistry for 5.1 Apparatus—Specialized apparatus requirements are
Metals, Ores, and Related Materials listed in the Apparatus section in each method.
E173Practice for Conducting Interlaboratory Studies of 5.1.1 In the methods specifying spectrophotometric testing,
Methods for Chemical Analysis of Metals (Withdrawn thecellsutilizedtocontainthereferencematerialsolutionsand
1998) sample solutions in spectrophotometers are referred to as
E350Test Methods for Chemical Analysis of Carbon Steel, “absorption cells”. Please note that the radiant energy passed
Low-Alloy Steel, Silicon Electrical Steel, Ingot Iron, and through the cells can be measured as absorbance or transmit-
Wrought Iron tance.Thesemethodsrefertoabsorbancemeasurements.Refer
E352TestMethodsforChemicalAnalysisofToolSteelsand to Practices E60 for details.
Other Similar Medium- and High-Alloy Steels
5.2 Reagents:
E353Test Methods for Chemical Analysis of Stainless,
5.2.1 Purity of Reagents—Reagent grade chemicals shall be
Heat-Resisting, Maraging, and Other Similar Chromium-
used in all tests. Unless otherwise indicated, it is intended that
Nickel-Iron Alloys
all reagents conform to the specifications of the Committee on
E354 Test Methods for Chemical Analysis of High-
Analytical Reagents of theAmerican Chemical Society where
Temperature,Electrical,Magnetic,andOtherSimilarIron, 5
such specifications are available. Other grades may be used,
Nickel, and Cobalt Alloys
provided it is first ascertained that the reagent is of sufficiently
E882Guide for Accountability and Quality Control in the
high purity to permit its use without lessening the accuracy of
Chemical Analysis Laboratory
the determination.
E1019Test Methods for Determination of Carbon, Sulfur,
Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,
For referenced ASTM standards, visit the ASTM website, www.astm.org, or 4th Floor, New York, NY 10036, http://www.ansi.org.
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Reagent Chemicals, American Chemical Society Specifications, American
Standards volume information, refer to the standard’s Document Summary page on Chemical Society, Washington, DC. For suggestions on the testing of reagents not
the ASTM website. listed by theAmerican Chemical Society, see the United States Pharmacopeia and
The last approved version of this historical standard is referenced on National Formulary,U.S.PharmacopeialConvention,Inc.(USPC),Rockville,MD.
www.astm.org.
E351 − 18
5.2.2 Purity of Water—Unless otherwise indicated, refer- 13. Interferences
ences to water shall be understood to mean reagent water as
13.1 The elements ordinarily present do not interfere.
conforming to Type I or Type II of Specification D1193. Type
HClO treatment, which is used in the procedure, yields
IIIorIVmaybeusediftheyeffectnomeasurablechangeinthe
solutionswhichcanbehighlycoloredduetothepresenceofCr
blank or sample.
(VI) ions. Although these ions and other colored ions in the
5.3 Spectrophotometric Practice—Spectrophotometric sample solution undergo no further change in color quality
practice prescribed in these test methods shall conform to upon treatment with metaperiodate ion, the following precau-
Practice E60. tions must be observed when filter spectrophotometers are
used: Select a filter with maximum transmittance between 545
6. Hazards
nm and 565 nm. The filter must transmit not more than 5% of
6.1 For precautions to be observed in the use of certain its maximum at a wavelength shorter than 530 nm. The band
reagents and equipment in these methods, refer to Practices
width of the filter should be less than 30 nm when measured at
E50. 50% of its maximum transmittance. Similar restrictions apply
with respect to the wavelength region employed when other
7. Sampling
“wide-band” instruments are used.
7.1 For procedures to sample the material, refer to Practice
13.2 The spectral transmittance curve of permanganate ions
E1806.
exhibits two useful minima, one at approximately 526 nm, and
the other at 545 nm. The latter is recommended when a
8. Interlaboratory Studies and Rounding Calculated
“narrow-band” spectrophotometer is used.
Values
8.1 These test methods have been evaluated as directed in 14. Reagents
Practice E173 (withdrawn 1997) or ISO 5725. Practice E173
14.1 Manganese, Standard Solution (1 mL=0.032 mg
has been replaced by Practice E1601. The Reproducibility R2
Mn)—Transfer the equivalent of 0.4000 g of assayed, high-
of E173 corresponds to the Reproducibility Index R of E1601.
purity manganese (purity: 99.99% minimum), to a 500-mL
TheRepeatabilityR1ofE173correspondstotheRepeatability
volumetric flask and dissolve in 20 mL of HNO by heating.
Index r of E1601.
Cool, dilute to volume, and mix. Using a pipet, transfer 20 mL
8.2 Rounding of test results obtained using these test meth-
to a 500-mL volumetric flask, dilute to volume, and mix.
ods shall be performed as directed in ASTM E29, Rounding
14.2 Nitric-Phosphoric Acid Mixture—Cautiously, while
Method, unless an alternative rounding method is specified by
stirring,add100mLofHNO and400mLofH PO to400mL
3 3 4
the customer or applicable material specification.
of water. Cool, dilute to 1 L, and mix. Prepare fresh as needed.
14.3 Potassium Metaperiodate Solution(7.5g/L)—Dissolve
MANGANESE BY THE METAPERIODATE
7.5 g of potassium metaperiodate (KIO ) in 200 mL of hot
SPECTROPHOTOMETRIC METHOD
HNO (1+1), add 400 mL of H PO , cool, dilute to 1 L, and
3 3 4
mix.
9. Scope
14.4 Water, Pretreated with Metaperiodate—Add 20 mL of
9.1 Thistestmethodcoversthedeterminationofmanganese
KIO solution to 1 Lof water, mix, heat at not less than 90 °C
from 0.10 % to 2.00 %.
for 20 min to 30 min, and cool. Use this water to dilute
solutions to volume that have been treated with KIO solution
10. Summary of Method
to oxidize manganese, and thus avoid reduction of permangan-
10.1 Manganous ions are oxidized to permanganate ions by
ate ions by any reducing agents in the untreated water.
reaction with metaperiodate ions. Solutions of the samples are
(Caution—Avoid the use of this water for other purposes.)
fumed with HClO so that the effect of metaperiodate ion is
limited to the oxidation of manganese. Spectrophotometric
15. Preparation of Calibration Curve
absorbance measurement is made at 545 nm.
15.1 Calibration Solutions—Usingpipets,transfer5mL,10
mL,15mL,20mL,and25mLofmanganesestandardsolution
11. Concentration Range
(1 mL=0.032 mg Mn) to 50-mLborosilicate glass volumetric
11.1 The recommended concentration range is 0.15 mg to
flasks, and, if necessary, dilute to approximately 25 mL.
0.8 mg of manganese per 50 mLof solution, using a 1-cm cell
Proceed as directed in 15.3.
(Note 1) and a spectrophotometer with a band width of 10 nm
15.2 Reference Solution—Transfer approximately 25 mL of
or less.
water to a 50-mL borosilicate glass volumetric flask. Proceed
NOTE 1—This method has been written for cells having a 1-cm light
as directed in 15.3.
path and a narrow-band instrument. The concentration range depends
upon band width and spectral region used as well as cell optical path
15.3 Color Development—Add 10 mL of KIO solution,
length. Cells having other dimensions may be used, provided suitable
and heat the solutions at not less than 90 °C for 20 min to 30
adjustments can be made in the amounts of sample and reagents used.
min(Note2).Cool,dilutetovolumewithpretreatedwater,and
mix.
12. Stability of Color
12.1 The color is stable for at least 24 h. NOTE 2—Immersing the flasks in a boiling water bath is a preferred
E351 − 18
means of heating them for the specified period to ensure complete color
16.2 Reagent Blank Solution—Carry a reagent blank
development.
through the entire procedure using the same amounts of all
reagents with the sample omitted.
15.4 Spectrophotometry:
15.4.1 Multiple-Cell Spectrophotometer—Measure the cell
16.3 Color Development—Proceed as directed in 15.3.
correction using the Reference Solution (15.2) in absorption
16.4 Reference Solutions:
cells with a 1-cm light path and using a light band centered at
16.4.1 Background Color Solution—To one of the sample
545 nm. Using the test cell, take the spectrophotometric
aliquots in a 50-mL volumetric flask, add 100 mL of HNO -
absorbance readings of the calibration solutions versus the
H PO mixture, and heat the solution at not less than 90 °C for
3 4
Reference Solution (15.2).
20minto30min(Note2in15.3).Cool,dilutetovolume(with
15.4.2 Single-Cell Spectrophotometer—Transfer a suitable
untreated water), and mix.
portion of the Reference Solution (15.2) to an absorption cell
16.4.2 Reagent Blank Reference Solution—Transfer the re-
with a 1-cm light path and adjust the spectrophotometer to the
agentblanksolution(16.2)tothesamesizevolumetricflaskas
initial setting, using a light band centered at 545 nm. While
usedforthetestsolutionsandtransferthesamesizealiquotsas
maintaining this adjustment, take the spectrophotometric ab-
used for the test solutions to two 50-mL volumetric flasks.
sorbance readings of the calibration solutions.
Treat one portion as directed in 16.3 and use as reference
15.5 Calibration Curve—Follow the instrument manufac-
solution for test samples. Treat the other as directed in 16.4.1
turer’s instructions for generating the calibration curve. Plot
and use as reference solution for Background Color Solutions.
the net spectrophotometric absorbance readings of the calibra-
16.5 Spectrophotometry—Establishthecellcorrectionswith
tion solutions against the milligrams of manganese per 50 mL
theReagentBlankReferencesolutiontobeusedasareference
of solution.
solution for Background Color solutions. Take the spectropho-
tometric absorbance readings of the Background Color Solu-
16. Procedure
tionsandthetestsolutionsversustherespectiveReagentBlank
16.1 Test Solution:
Reference Solutions as directed in 15.4.
16.1.1 Select and weigh a sample as follows:
17. Calculation
Tolerance in
Maganese, Sample Sample Mass, Dilution,
17.1 Convertthenetspectrophotometricabsorbancereading
% Mass, g mg mL
of the test solution and of the background color solution to
0.01 to 0.5 0.80 0.5 100
milligrams of manganese by means of the calibration curve.
0.45 to 1.0 0.35 0.3 100
Calculate the percentage of manganese as follows:
0.85 to 2.0 0.80 0.5 500
Manganese,% 5 A 2 B / C 310 (1)
~ ! ~ !
Transfer it to a 300-mL Erlenmeyer flask.
16.1.2 TodissolvesamplesthatdonotrequireHF,add8mL
where:
to 10 mL of HCl (1+1), and heat. Add HNO as needed to
A = manganese, mg, found in 50 mL of the final test
hastendissolution,andthenadd3mLto4mLinexcess.When
solution,
dissolution is complete, cool, then add 10 mL of HClO ;
B = apparent manganese, mg, found in 50 mL of the final
evaporate to fumes to oxidize chromium, if present, and to
background color solution, and
expelHCl.Continuefuminguntilsaltsbegintoseparate.Cool,
C = sample mass, g, represented in 50 mL of the final test
add 50 mL of water, and digest if necessary to dissolve the
solution.
salts. Cool and transfer the solution to either a 100-mL or
500-mL volumetric flask as indicated in 16.1.1. Proceed to
18. Precision and Bias
16.1.4.
18.1 Precision—Nine laboratories cooperated in testing this
16.1.3 For samples whose dissolution is hastened by HF,
methodandobtainedthedatasummarizedinTable1.Although
treat them by adding 8 mL to 10 mL of HCl (1+1), and
a sample covered by this method with manganese composition
heating.Add HNO and a few drops of HF as needed to hasten
of approximately 2.0 % was not available, the precision data
dissolution, and then add 3 mL to 4 mL of HNO . When
for this composition should be similar to those obtained for
dissolution is complete, cool, then add 10 mL of HClO ,
material 5.
evaporate to fumes to oxidize chromium, if present, and to
expelHCl.Continuefuminguntilsaltsbegintoseparate.Cool,
add 50 mL of water, digest if necessary to dissolve the salts,
TABLE 1 Statistical Information—Manganese by the
Metaperiodate Spectrophotometric Method
cool, and transfer the solution to either a 100-mL or 500-mL
volumetric flask as indicated in 16.1.1.
Man- Repeat- Repro-
ganese ability ducibil-
16.1.4 Cool the solution to room temperature, dilute to
Test Specimen
Found, (R , ity (R ,
1 2
volume, and mix.Allow insoluble matter to settle, or dry-filter
% E173) E173)
through a coarse paper and discard the first 15 mLto 20 mLof
1. White cast iron (NIST 3a, 0.317 Mn) 0.318 0.006 0.017
the filtrate, before taking aliquots.
2. Cast iron (NIST 4i, 0.793 Mn) 0.793 0.018 0.028
3. Cast iron (B.C.S. 236/2, 1.14 Mn) 1.15 0.03 0.06
16.1.5 Using a pipet, transfer 20 mLaliquots, to two 50-mL
4. White cast iron (NIST 1175, 1.64 Mn) 1.64 0.02 0.08
borosilicate glass volumetric flasks. Treat one portion as
5. Low-alloy steel (NIST 100b, 1.89 Mn) 1.91 0.02 0.04
directed in 16.3. Treat the other portion as directed in 16.4.1.
E351 − 18
18.2 Bias—The accuracy of this test method has been 25.3 Hydrazine Sulfate Solution (1.5 g/L)—Dissolve 1.5 g
deemed satisfactory based upon the data for the certified of hydrazine sulfate ((NH ) ·H SO ) in water, dilute to 1 L,
2 2 2 4
reference materials in Table 1. Users are encouraged to use and mix. Discard any unused solution after 24 h.
these or similar reference materials to verify that the test
25.4 Phosphorus Standard Solution A (1 mL = 1.0 mg
method is performing accurately in their laboratories.
P)—Transfer 2.292 g of anhydrous disodium hydrogen phos-
phate(Na HPO ),previouslydriedtoconstantmassat105°C,
2 4
to a 500-mL volumetric flask; dissolve in about 100 mL of
PHOSPHORUS BY THE MOLYBDENUM BLUE
water, dilute to volume, and mix.
SPECTROPHOTOMETRIC METHOD
25.5 Phosphorus Standard Solution B (1 mL = 0.01 mg
19. Scope
P)—Using a pipet, transfer 10 mL of Solution A (1 mL = 1.0
19.1 This method covers the determination of phosphorus
mg P) to a 1-Lvolumetric flask, add 50 mLof HClO (1 + 5),
from 0.02 % to 0.90 %.
dilute to volume, and mix.
25.6 Phosphorus Standard Solution C (1 mL = 0.10 mg
20. Summary of Method
P)—Using a pipet, transfer 50 mL of Solution A (1 mL = 1.0
20.1 The sample is dissolved in mixed acids and the
mg P) to a 500-mL volumetric flask, add 50 mL of HClO (1
solutionisfumedwithHClO .Ammoniummolybdateisadded
+ 5), dilute to volume, and mix.
to react with the phosphorus to form the heteropoly phospho-
25.7 Sodium Sulfite Solution (100 g/L)—Dissolve 100 g of
molybdate.This species is then reduced with hydrazine sulfate
sodium sulfite (Na SO ) in water, dilute to 1 L, and mix.
2 3
to form the molybdenum blue complex. Spectrophotometric
absorbance measurement is made at 650 nm or 825 nm,
26. Preparation of Calibration Curve for Concentrations
depending upon the concentration.
from 0.005 mg/100 mL to 0.05 mg/100 mL
21. Concentration Range
26.1 Calibration Solutions—Usingpipets,transfer5mL,10
mL, 15 mL, 25 mL, and 50 mL of Phosphorus Standard
21.1 The recommended concentration range is from 0.005
mg to 0.05 mg of phosphorus per 100 mL of solution when Solution B (1 mL = 0.01 mg P) to 100-mL volumetric flasks.
Add20mLofHClO ,dilutetovolume,andmix.Usingapipet,
measuredat825nmandfrom0.05mgto0.3mgofphosphorus
per 100 mL of solution when measured at 650 nm, using a transfer 10 mLof each solution to a 100-mLborosilicate glass
volumetric flask. Proceed as directed in 26.3.
1-cm cell.
NOTE3—Thistestmethodhasbeenwrittenforcellshavinga1-cmlight
26.2 Reagent Blank—Transfer 12 mLof HClO (1+5)toa
path. Cells having other dimensions may be used, provided suitable
100-mL borosilicate glass volumetric flask.
adjustments can be made in the amounts of sample and reagents used.
26.3 Color Development:
22. Stability of Color
26.3.1 Add 15 mLof Na SO solution, boil gently for 30 s,
2 3
22.1 The molybdenum blue complex is stable for at least 2
and add 50 mL of ammonium molybdate-hydrazine sulfate
h.
solution that has been prepared within the hour.
26.3.2 Heat the solutions at not less than 90 °C for 20 min,
23. Interferences
quickly cool, dilute to volume, and mix.
23.1 None of the elements usually present interfere except
NOTE 4—Immersing the flasks in a boiling water bath is the preferred
arsenic, which is removed by volatilization as the bromide.
means of heating them for complete color development.
26.4 Reference Solution—Water.
24. Apparatus
26.5 Spectrophotometry:
24.1 Glassware must be phosphorus- and arsenic-free. Boil
the glassware with HCl and rinse with water before use. It is
26.5.1 Multiple-Cell Spectrophotometer—Measure the re-
recommendedthattheglasswareusedforthisdeterminationbe agent blank (which includes the cell correction) versus the
reservedforthisuseonly.Manydetergentscontainphosphorus
reference solution (26.4) using absorption cells with a 1-cm
and must not be used for cleaning purposes. lightpathandusingalightbandcenteredat825nm.Usingthe
test cell, take the spectrophotometric absorbance readings of
25. Reagents
the calibration solutions versus the reference solution.
26.5.2 Single-Cell Spectrophotometer—Transfer a suitable
25.1 Ammonium Molybdate Solution (20 g/L)—Cautiously,
portion of the reference solution (26.4) to an absorption cell
whilestirringandcooling,add300mLofH SO to500mLof
2 4
with a 1-cm light path and adjust the spectrophotometer to the
water and cool. Add 20 g of ammonium heptamolybdate
initial setting using a light band centered at 825 nm. While
((NH ) Mo O ·4H O), cautiously dilute to 1 L, and mix.
4 6 7 24 2
maintaining this adjustment, take the spectrophotometric ab-
25.2 Ammonium Molybdate-Hydrazine Sulfate Solution—
sorbance readings of the reagent blank solution and of the
Dilute 250 mL of the ammonium molybdate solution to 600
calibration solutions.
mL, add 100 mL of the hydrazine sulfate solution, dilute to 1
L, and mix. Do not use a solution that has stood for more than 26.6 Calibration Curve—Follow the instrument manufac-
1h. turer’s instructions for generating the calibration curve. Plot
E351 − 18
the net spectrophotometric absorbance readings of the calibra- tosettleordryfilterthesolution.Usingapipet,transfer10-mL
tionsolutionsagainstthemilligramsofphosphorusper100mL portions to two 100-mL borosilicate glass volumetric flasks;
of solution. treat one as directed in 28.3 and the other as directed in 28.4.2.
28.1.3 Treat samples of white iron as directed in 28.1.3.1
27. Preparation of Calibration Curve for Concentrations
and 28.1.3.2.
from 0.05 mg/100 mL to 0.30 mg/100 mL
28.1.3.1 Crush the material in an iron mortar and weigh
27.1 Calibration Solutions—Usingpipets,transfer5mL,10
only particles passing through a 300-µm (No. 50) sieve.
mL,15mL,20mL,25mL,and30mLofPhosphorusStandard
Transfer the weighed sample to a 250-mL Erlenmeyer flask.
Solution C (1 mL = 0.10 mg P) to 100-mL volumetric flasks.
Add 15 mL of HNO and 5 mL of HBr. Heat until dissolution
Add20mLofHClO ,dilutetovolume,andmix.Usingapipet,
4 is complete.Add 10 mLof HClO , evaporate to copious white
transfer 10 mLof each solution to a 100-mLborosilicate glass
fumes; then, without delay, fume strongly enough to cause the
volumetric flask.
white fumes to clear the neck of the flask, and continue at this
rate for 1 min.
27.2 Reagent Blank—Proceed as directed in 26.2.
28.1.3.2 Coolthesolution,add60mLofHClO (1+5),and
27.3 Color Development—Proceed as directed in 26.3.
swirl to dissolve the salts. Transfer to a 100-mL volumetric
27.4 Reference Solution—Water.
flask, cool, dilute to volume, and mix. Allow insoluble matter
tosettleordryfilterthesolution.Usingapipet,transfer10-mL
27.5 Spectrophotometry:
portions to two 100-mL borosilicate glass volumetric flasks;
27.5.1 Multiple-Cell Spectrophotometer—Measure the re-
treat one as directed in 28.3 and the other as directed in 28.4.2.
agent blank (which includes the cell correction) versus the
reference solution (27.4) using absorption cells with a 1-cm
28.2 Reagent Blank Solution—Carry a reagent blank
light path and a light band centered at 650 nm. Using the test
through the entire procedure using the same amount of all
cell, take the spectrophotometric absorbance readings of the
reagents with the sample omitted.
calibration solutions versus the reference solution.
28.3 Color Development—Proceed with one of the 10-mL
27.5.2 Single-Cell Spectrophotometer—Transfer a suitable
portions obtained in 28.1.2.2 or 28.1.3.2, as directed in 26.3.
portion of the reference solution (27.4) to an absorption cell
with a 1-cm light path and adjust the spectrophotometer to the
28.4 Reference Solutions:
initial setting using a light band (no change) centered at 650
28.4.1 Water—Use this as the reference solution for the
nm. While maintaining this adjustment, take the spectrophoto-
reagent blank solution.
metricabsorbancereadingsofthereagentblanksolutionandof
28.4.2 Background Color Reference Solution—Add 15 mL
the calibration solutions.
of Na SO solution to the second 10-mL portion obtained in
2 3
27.6 Calibration Curve—Follow the instrument manufac-
28.1.2.2 or 28.1.3.2. Boil gently for 30 s, add 50 mLof H SO
2 4
turer’s instructions for generating the calibration curve. Plot
(3 + 37), cool, dilute to volume, and mix. Use this as the
the net spectrophotometric absorbance readings of the calibra-
reference solution for the test solution.
tionsolutionsagainstthemilligramsofphosphorusper100mL
28.5 Spectrophotometry—Take the spectrophotometric ab-
of solution.
sorbance readings of the reagent blank solution and of the test
28. Procedure solution (using the respective reference solutions) as directed
in 26.5 or 27.5 depending upon the estimated composition of
28.1 Test Solution:
phosphorus in the sample.
28.1.1 Select and weigh a sample as follows:
Sample Tolerance in
29. Calculation
Phosphorus, % Mass, g Sample Mass, mg
29.1 Convertthenetspectrophotometricabsorbancereading
0.020 to 0.30 1.0 0.5
0.30 to 0.60 0.5 0.3 of the test solution and of the reagent blank solution to
0.60 to 0.90 0.25 0.1
milligrams of phosphorus by means of the appropriate calibra-
Transfer it to a 250-mL Erlenmeyer flask.
tion curve. Calculate the percent of phosphorus as follows:
28.1.2 If the sample is other than white iron, proceed as
Phosphorus,% 5 ~A 2 B!⁄~C 3 10! (2)
directed in 28.1.2.1 and 28.1.2.2.
28.1.2.1 Add 15 mL of a freshly prepared mixture of 1
volume of HNO and 3 volumes of HCl, slowly and in small
portions. When the reaction has ceased, add 10 mL of HClO
TABLE 2 Statistical Information—Phosphorus—Molybdenum
and evaporate to fumes. Remove the flask immediately to
Blue—Spectrophotometric Method
avoid undue loss of HClO , cool, and add 20 mL of HBr (1 +
Phos- Repeat- Repro-
4). Evaporate the solution to copious white fumes and then,
phorus ability ducibil-
Test Specimen
without delay, fume strongly enough to cause the white fumes Found, (R , ity (R ,
1 2
% E173) E173)
tocleartheneckoftheflask,andcontinueatthisratefor1min.
1. Cast iron 15Ni-2Cr-5Cu (NIST 115, 0.114 P) 0.107 0.013 0.014
28.1.2.2 Coolthesolution,add60mLofHClO (1+5),and
2. Cast iron (NIST 5k, 0.263 P) 0.257 0.016 0.012
swirl to dissolve the salts. Transfer to a 100-mL volumetric
3. Cast iron (NIST 7g, 0.794 P) 0.779 0.020 0.053
flask, cool, dilute to volume, and mix. Allow insoluble matter
E351 − 18
where: % silicon for samples containing more than 0.10 % by
determining duplicate values for silicon as directed in 49.2.2 –
A = phosphorus found in 100 mL of the final test solution,
49.2.6.
mg,
49.2.2 Transfer 15 mL of HClO (Note 5) to each of two
B = phosphorus found in 100 mL of the final reagent blank
400-mL beakers. To one of the beakers transfer an additional
solution, mg, and
C = sample represented in 100 mL of the final test solution, 50 mL of HClO . Using a pipet, transfer 20 mL of Na SiO
4 2 3
solution(1mL=1.00mgSi)toeachofthebeakers.Evaporate
g.
the solutions to fumes and heat for 15 min to 20 min at such a
30. Precision and Bias
rate that HClO refluxes on the sides of the beakers. Cool
sufficiently, and add 100 mL of water (40 °C to 50 °C).
30.1 Precision—Nine laboratories cooperated in testing this
method and obtained the data summarized in Table 2.
NOTE5—The15-mLadditionofHClO canbefromthesamelotasthe
onetobetested.Oncealothasbeenestablishedashavinglessthan0.0002
30.2 Bias—The accuracy of this test method exhibits a
% silicon, it should preferably be used for the 15-mL addition in all
slight negative bias based upon the data for the certified
subsequent tests of other lots of acid.
reference materials in Table 2. Users are encouraged to use
these or similar reference materials to verify that the test 49.2.3 Addpaperpulpandfilterimmediately,usinglow-ash
method is performing accurately in their laboratories. 11-cm medium-porosity filter papers. Transfer the precipitates
to the papers, and scrub the beakers thoroughly with a
rubber-tipped rod.Wash the papers and precipitates alternately
SULFUR BY THE GRAVIMETRIC METHOD
with 3-mLto 5-mLportions of hot HCl (1 + 19) and hot water,
foratotalof6times.FinallywashthepaperstwicewithH SO
2 4
This test method, which consisted of Sections 30 through 36,
(1 + 49). Transfer the papers to platinum crucibles.
was discontinued in 1988.
49.2.4 Dry the papers and heat at 600 °C until the carbon is
SULFUR BY THE COMBUSTION-IODATE
removed.Finallyigniteat1100°Cto1150°Ctoconstantmass
TITRATION METHOD
(at least 30 min). Cool in a desiccator and weigh.
49.2.5 Add enough H SO (1 + 1) to moisten the SiO , and
2 4 2
This test method, which consisted of Sections 37 through 45,
add 3 mL to 5 mL of HF. Evaporate to dryness and then heat
was discontinued in 2012.
at a gradually increasing rate until H SO is removed. Ignite
2 4
for 15 min at 1100 °C to 1150 °C, cool in a desiccator, and
SILICON BY THE GRAVIMETRIC METHOD
weigh.
49.2.6 Calculate the percent of silicon as follows:
46. Scope
Silicon,% 5 A 2 B 2 C 2 D 30.4674⁄E 3100 (3)
@~ ! ~ !#
46.1 This method covers the determination of silicon from
0.1 % to 6.1 %. where:
A = initialmassofcrucibleplusimpureSiO when65mLof
47. Summary of Test Method
HClO was taken, g,
47.1 After dissolution of the sample, silicic acid is dehy-
B = final mass of crucible plus impurities when 65 mL of
drated by fuming with H SO or HClO . The solution is
HClO was taken, g,
2 4 4
filtered,andtheimpuresilicaisignitedandweighed.Thesilica C = initialmassofcrucibleplusimpureSiO when15mLof
isthenvolatilizedwithHF.Theresidueisignitedandweighed; HClO was taken, g,
D = final mass of crucible plus impurities when 15 mL of
the loss in mass represents silica.
HClO was taken, g, and
48. Interferences
E = nominal mass (80 g) of 50 mL of HClO .
48.1 Theelementsordinarilypresentdonotinterfereiftheir
49.3 Sodium Silicate Solution—Transfer 11.0 g of sodium
compositions are under the maximum limits shown in 1.1.
silicate (Na SiO ·9H O) to a 400-mL beaker. Add 150 mL of
2 3 2
water and dissolve the salt. Filter through a medium paper,
49. Reagents
collecting the filtrate in a 1-L volumetric flask, dilute to
49.1 The analyst should ensure by analyzing blanks and
volume, and mix. Store in a polyethylene bottle. Use this
other checks that possible silicon contamination of reagents
solution to determine the suitability of the HClO .
will not significantly bias the results.
49.4 Tartaric Acid Solution (20.6 g/L)—Dissolve 20.6 g of
49.2 Perchloric Acid (HClO ):
tartaric acid (C H O ) in water, dilute to 1 L, and filter.
4 6 6
49.2.1 Select a lot of HClO that contains not more than
0.0002 % silicon for the analysis of samples containing silicon 49.5 Water—Use freshly prepared Type II water known to
in the range from 0.02 % to 0.10 % and not more than 0.0004 be free of silicon. Water distilled from glass, demineralized in
E351 − 18
TABLE 3 Statistical Information—Silicon—Gravimetric Method
columns containing silicon compounds, or stored for extended
periods in glass, or combination thereof, has been known to Repeat- Repro-
Silicon
ability ducibil-
absorb silicon.
Test Specimen Found,
(R , ity (R ,
1 2
%
E173) E173)
50. Procedure
HClO Dehydration
50.1 Select and weigh a sample as follows:
1. Cast iron 1.2Ni-0.3Cr-0.8 Mo (NIST 1.36 0.02 0.02
107b, 1.35 Si)
Tolerance Dehydrating Acid, mL
2. Cast iron (NIST 4i, 1.45 Si) 1.45 0.04 0.05
Sample in Sample H SO
2 4
3. Cast iron 1.07Ni-0.32Cr (NIST 82a, 2.08 0.04 0.05
Silicon, % Mass, g Mass, mg (1+4) HClO
2.07 Si)
4. Cast iron (NIST 5k, 2.08 Si) 2.08 0.03 0.05
0.10 to 1.00 4.0 4 150 60
5. Cast iron, high (0.79) phosphorus 2.40 0.04 0.07
1.00 to 2.00 3.0 3 100 50
(NIST 7g, 2.41 Si)
2.00 to 4.00 2.0 2 100 40
6. White cast iron (NIST 1176, 3.19 Si) 3.20 0.03 0.10
4.00 to 6.00 1.0 1 100 40
H SO Dehydration
2 4
Transfer it to a 400-mL beaker or a 300-mL porcelain
1. Cast iron 1.2Ni-0.3Cr-0.8Mo (NIST 1.36 0.02 0.03
107b, 1.35 Si)
casserole.
2. Cast iron (NIST 4i, 1.45 Si) 1.45 0.04 0.06
3. Cast iron 1.07Ni-0.32Cr (NIST 82a, 2.08 0.04 0.04
50.2 If the sample type is other than white iron, proceed as
2.07 Si)
directed in 50.3; treat samples of white iron as directed in
4. Cast iron (NIST 5k, 2.08 Si) 2.08 0.04 0.05
50.2.1.
5. Cast iron, high (0.79) phosphorus 2.41 0.03 0.05
(NIST 7g, 2.41 Si)
50.2.1 Crush the material in an iron mortar and use only
particles passing through a 150-µm (No. 100) sieve. Add 30
mLofHNO and10mLofHBr.Whenthedissolutionreaction
becomes passive, decant the bulk of the solution to a 400-mL
beaker and crush the remaining insoluble matter in the original
dehydrating acid used. Filter immediately, using a low-ash,
beaker with a glass rod. Add 20 mL of HNO and 10 mL of
3 9-cm-100-porosity filter paper, and wash as directed in 50.3.
HBr, and heat gently until dissolution is complete. Combine
50.5 Transfer the paper and precipitate to the reserved
the two portions of the solution and add the amount of H SO
2 4
platinum crucible. Dry the papers and then heat the crucible at
or HClO specified in 50.1.
600 °C until the carbon is removed. Finally ignite at 1100 °C
50.2.2 H SO Dehydration:
2 4
to 1150 °C to constant mass (at least 30 min). Cool in a
50.2.2.1 Evaporate until salts begin to separate; at this point
desiccator and weigh.
evaporate the solution rapidly to the first appearance of fumes
50.6 Add enough H SO (1 + 1) to moisten the impure
andfumestronglyfor2minto3min.Coolsufficiently,andadd
2 4
SiO , and add 3 mL to 5 mL of HF. Evaporate to dryness and
100mLofwater(40°Cto50°C).Stirtodissolvethesaltsand
thenheatatagraduallyincreasingrateuntilH SO isremoved.
heat, if necessary, but do not boil. Proceed immediately as
2 4
Ignite at 1100 °C to 1150 °C for 15 min, cool in a desiccator,
directed in 50.4.
and weigh.
50.2.3 HClO Dehydration:
50.2.3.1 Evaporate the solution to fumes and heat for 15
51. Calculation
min to 20 min at such a rate that the HClO refluxes on the
sides of the container. Cool sufficiently and add 100 mL of
51.1 Calculate the percent of silicon as follows:
water (40 °C to 50 °C). Stir to dissolve the salts and heat to
Silicon,% 5 @~~A 2 B! 3 0.4674!⁄C# 3100 (4)
boiling. If the sample solution contains more than 100 mg of
chromium,add,whilestirring,1mLoftartaricacidsolutionfor where:
each 25 mg of chromium.
A = initial mass of crucible and impure SiO,g,
B = final mass of crucible and residue, g, and
50.3 Add paper pulp and filter immediately, on a low-ash
C = sample used, g.
11-cm medium-porosity filter paper. Collect the filtrate in a
600-mLbeaker.Transfer the precipitate to the paper, and scrub
52. Precision and Bias
the container thoroughly with a rubber-tipped rod. Wash the
paperandprecipitatealternatelywith3-mLto5-mLportionsof 52.1 Precision—Eleven laboratories cooperated in testing
hot HCl (1 + 19) and hot water until iron salts are removed but this method and obtained the data summarized in Table 3.
Although samples covered by this method with silicon com-
for not more than a total of ten washings. If the HClO
dehydration method was followed, wash the paper twice more positions near the extreme limits of the scope were not
available for testing, the precision data obtained for low-alloy
with H SO (1 + 49), but do not collect these washings in the
2 4
filtrate; discard the washings. Transfer the paper to a platinum steels by Test Methods E350 should apply at the lower limit.
crucible and reserve.
52.2 Bias—The accuracy of this test method has been
50.4 Add 15 mLof HNO to the filtrate, stir, and evaporate deemed satisfactory based upon the data for the certified
as directed in either 50.2.2 or 50.2.3, depending upon the reference materials in Table 3. Users are encouraged to use
E351 − 18
these or similar reference materials to verify that the test having a nominal crosslinkage of 8 %, and 0.075-mm to
method is performing accurately in their laboratories. 0.037-mm (200-nominal to 400-nominal mesh) size. To re-
move those beads greater than about 180-µm in diameter as
well as the excessively fine beads, treat the resin as follows:
COBALT BY THE ION-EXCHANGE-
Transferasupplyoftheresintoabeaker,coverwithwater,and
POTENTIOMETRIC TITRATION METHOD
allow sufficient time (at least 30 min) for the beads to undergo
maximum swelling. Place a 180-µm (No. 80) screen, 150 mm
53. Scope
indiameterovera2-Lbeaker.Prepareathinslurryoftheresin
53.1 This test method covers the determination of cobalt
and pour it onto the screen. Wash the fine beads through the
from 2.0 % to 4.5 %.
screen, using a small stream of water. Discard the beads
retained on the screen, periodically, if necessary, to avoid
54. Summary of Method
unduecloggingoftheopenings.Whenthebulkofthecollected
54.1 Cobalt is separated from interfering elements by selec-
resin has settled, decant the water and transfer approximately
tive elution from an anion-exchange column using HCl. The
100 mLof resin to a 400-mLbeaker.Add 200 mLof HCl (1 +
cobalt is oxidized to the trivalent state with ferricyanide, and
19),stirvigorously,allowtheresintosettlefor4minto6min,
the excess ferricyanide is titrated potentiometrically with
decant 150 mL to 175 mL of the suspension, and discard.
cobalt solution.
RepeatthetreatmentwithHCl(1+19)twicemore,andreserve
55. Interferences
the coarser resin for the column preparation.
55.1 The elements normally present do not interfere if their 57.3.2 Prepare the column as follows: Place a 10-mm to
compositions are under the maximum limits shown in 1.1. 20-mmlayerofglasswoolorpolyvinylchlorideplasticfiberin
the bottom of the column, and add a sufficient amount of the
56. Apparatus
prepared resin to fill the column to a height of approximately
56.1 Ion-Exchange Column,approximately25mmindiam- 140 mm. Place a 20-mm layer of glass wool or polyvinyl
eter and 300 mm in length, tapered at one end, and provided
chloride plastic fiber at the top of the resin bed to protect it
with a stopcock to control the flow rate, and a second, lower
from being carried into suspension when the solutions are
stopcocktostoptheflow.AJonesReductor,maybeadaptedto
added. While passing a minimum of 35 mL of HCl (7 + 5)
thismethod.Areservoirfortheeluantsmaybeaddedatthetop
through the column, with the hydrostatic head 100 mm above
of the column.
the top of the resin bed, adjust the flow rate to not more than
3.0mLpermin.Drainto10mmto20mmabovethetopofthe
56.2 pH meter, with a platinum and a saturated calomel
resin bed and then close the lower stopcock.
electrode.
NOTE 6—The maximum limits of 0.125 g of cobalt and 0.500 g in the
57. Reagents
sample solution take into account the exchange capacity of the resin, the
57.1 Ammonium Citrate Solution (200 g/l)—Dissolve 200 g
physical dimensions of the column, and the volume of eluants.
of di–ammonium hydrogen citrate in water and dilute to 1 L.
57.4 Potassium Ferricyanide, Standard Solution (1
57.2 Cobalt, Standard Solution (1mL = 1.5 mg of Co).
mL=3.0 mg of Co):
57.2.1 Preparation—Dry a weighing bottle in an oven at
57.4.1 Dissolve 16.68 g of potassium ferricyanide
130 °C for 1 h, cool in a desiccator, and weigh.Transfer 3.945
6 (K Fe(CN) ) in water and dilute to 1 L. Store the solution in a
3 6
g of cobalt sulfate (CoSO ) that has been heated at 550 °C for
dark-colored bottle. Standardize the solution each day before
1 h to the weighing bottle. Dry the bottle and contents at 130
use as follows: Transfer from a 50-mLburet approximately 20
°C for 1 h, cool in desiccator, stopper the bottle, and weigh.
mL of K Fe(CN) solution to a 400-mL beaker. Record the
3 6
The difference in mass is the amount of CoSO taken.Transfer
buret reading to the nearest 0.01 mL.Add 25 mL of water, 10
the weighed CoSO to a 400-mL beaker, rinse the weighing
mLofammoniumcitratesolution,and25mLofNH OH.Cool
bottle with water, and transfer the rinsings to the beaker. Add 4
to 5 °C to 10 °C, and maintain this temperature during the
150 mLof water and 20 mLof HNO , and heat to dissolve the
titration. Transfer the beaker to the potentiometric titration
salts.Cool,transfertoa1-Lvolumetricflask,dilutetovolume,
apparatus.Whilestirring,titratetheK Fe(CN) withthecoba
...