ASTM C560-88(2010)e1
(Test Method)Standard Test Methods for Chemical Analysis of Graphite
Standard Test Methods for Chemical Analysis of Graphite
SIGNIFICANCE AND USE
These test methods provide a practical way to measure the concentration of certain trace elements in graphite. Many end uses of graphite require that it be free of elements which may be incompatible with certain nuclear applications. Other elemental contamination can affect the rate of oxidative degradation.
These test methods allow measurement of trace amounts of contaminants with a minimal amount of costly equipment. The colorimetric procedures used are accessible to most laboratories.
SCOPE
1.1 These test methods cover the chemical analysis of graphite.
1.2 The analytical procedures appear in the following order:
General Information
Relations
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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
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Designation: C560 − 88(Reapproved 2010) An American National Standard
Standard Test Methods for
Chemical Analysis of Graphite
This standard is issued under the fixed designation C560; 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.
´ NOTE—Updated 57.1 editorially in May 2010.
1. Scope 3. Significance and Use
3.1 These test methods provide a practical way to measure
1.1 These test methods cover the chemical analysis of
graphite. the concentration of certain trace elements in graphite. Many
end uses of graphite require that it be free of elements which
1.2 The analytical procedures appear in the following order:
may be incompatible with certain nuclear applications. Other
Sections
elemental contamination can affect the rate of oxidative deg-
Silicon by the Molybdenum Blue (Colorimetric) Test Method 8 to 14
radation.
Ironbythe o-Phenanthroline (Colorimetric) Test Method 15 to 21
Calcium by the Permanganate (Colorimetric) Test Method 22 to 28
3.2 Thesetestmethodsallowmeasurementoftraceamounts
Aluminum by the 2-Quinizarin Sulfonic Acid Test Method 29 to 35
Titanium by the Peroxide (Colorimetric) Test Method 36 to 43
of contaminants with a minimal amount of costly equipment.
Vanadium by the 3,38-Dimethylnaphthidine (Colorimetric) 44 to 51
The colorimetric procedures used are accessible to most
Test Method
laboratories.
Boron by the Curcumin-Oxalic Acid (Colorimetric) Test Method 52 to 59
1.3 The preferred concentration of sought element in the
4. Reagents
final solution, the limits of sensitivity, and the precision of the
4.1 Purity of Reagents—Reagent grade chemicals shall be
results are given in Table 1.
used in all tests. Unless otherwise indicated, it is intended that
1.4 The values stated in SI units are to be regarded as
all reagents shall conform to the specifications of the Commit-
standard. No other units of measurement are included in this
tee onAnalytical Reagents of theAmerican Chemical Society,
standard.
where such specifications are available. Other grades may be
used, provided it is first ascertained that the reagent is of
1.5 This standard does not purport to address all of the
sufficiently high purity to permit its use without lessening the
safety concerns, if any, associated with its use. It is the
accuracy of the determination.
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
4.2 When available, National Institute of Standards and
bility of regulatory limitations prior to use. See 56.1 for
Technology (NIST) certified reagents should be used as stan-
specific caution statement.
dards in preparing calibration curves.
4.3 Unless otherwise indicated, references to water shall be
2. Referenced Documents
understood to mean reagent water conforming to Specification
2.1 ASTM Standards:
D1193.
C561 Test Method for Ash in a Graphite Sample
4.4 National Institute of Standards and Technology certified
D1193 Specification for Reagent Water
reagents specified in certain steps of this procedure may no
E29 Practice for Using Significant Digits in Test Data to
longerbeavailable.IfNISTreagentsarenotavailable,thenthe
Determine Conformance with Specifications
highest purity reagent grade shall be substituted.
5. Sampling
These test methods are under the jurisdiction of ASTM Committee D02 on 5.1 The entire sample of graphite should be crushed and
Petroleum Products and Lubricants and are the direct responsibility of Subcommit-
ground to pass a No. 60 (250-µm) sieve in a roll crusher. The
tee D02.F0 on Petroleum Products and Lubricants
Current edition approved May 1, 2010. Published May 2010. Originally
ϵ1
approved in 1965. Last previous edition approved in 2005 as C560 – 88 (2005) . Reagent Chemicals, American Chemical Society Specifications, American
DOI: 10.1520/C0560-88R10E01. Chemical Society, Washington, DC. For suggestions on the testing of reagents not
For referenced ASTM standards, visit the ASTM website, www.astm.org, or listed by the American Chemical Society, see Analar Standards for Laboratory
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
Standards volume information, refer to the standard’s Document Summary page on and National Formulary, U.S. Pharmaceutical Convention, Inc. (USPC), Rockville,
the ASTM website. MD.
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C560 − 88 (2010)
TABLE 1 Concentration of Elements, Limits of Sensitivity, and
11.3 Silicon, Standard Solution (1 mL = 1 mg Si)—Dissolve
Reproducibility
10.1 g of sodium silicate (Na SiO ·9H O) in water and dilute
2 3 2
Concentration Reproducibility,
to 1 L in a volumetric flask. Store in a polyethylene bottle.
Range, µg/mL Sensitivity Limit, Relative, %
Determine exact concentration by the standard gravimetric
Element Solution µg/mL Solution (σ/x × 100)
procedure.
Silicon 10 to 100 µg/100 mL 1 µg/100 mL ±4
Iron 100 to 600 µg/100 mL 40 µg/100 mL ±5
11.4 Silicon, Working Solution (1 mL = 0.01 mg Si)—Dilute
Calcium 600 to 3000 µg/100 mL 50 µg/100 mL ±5
10 mL of standard silicon solution (1 mL = mg Si) to 1 L in a
Aluminum 10 to 100 µg/100 mL 2 µg/100 mL ±0.1
Titanium 600 to 3000 µg/100 mL 200 µg/100 mL ±2
volumetric flask. Transfer to a polyethylene bottle.
Vanadium 10 to 130 µg/50 mL 5 µg/50 mL ±5
Boron 0.5 to 1.4 µg/50 mL 0.1 µg/50 mL ±20
11.5 Sodium Carbonate Solution (100 g/L)—Dissolve 100 g
ofsodiumcarbonate(Na CO )inwateranddiluteto1L.Store
2 3
in a polyethylene bottle.
11.6 Stannous Chloride Solution—Dissolve 2.5 g of stan-
sample may have been reduced in size initially by drilling the
nous chloride (SnCl ·2H O) in 5 mL of hot concentrated HCl
2 2
test bar with silicon carbide-tipped drills.
(sp gr 1.19) and dilute to 250 mL with water. Prepare a fresh
solution every 2 weeks.
6. Rounding Calculated Values
6.1 Calculated values shall be rounded to the desired num- 11.7 Sulfuric Acid (H SO ) (1+3)—Carefully mix 1 volume
2 4
ber of places in accordance with Practice E29. of concentrated H SO , sp gr 1.84 with 3 volumes of water.
2 4
7. Precision and Bias
12. Preparation of Calibration Curve
7.1 No statement is being made about either the precision or
12.1 Calibration Solutions—Transfer 0, 1.0, 3.0, 5.0, 7.0,
bias of these test methods. At this time Committee C05 is
and 10 mL of silicon working solution (1 mL = 0.01 mg Si) to
investigating new standard methods of chemical analysis of
100-mL volumetric flasks. Add 5 drops of H SO (1+3) and
2 4
graphite that will eventually replace these test methods. For
dilute to approximately 10 mL.
this reason, no statistical study of these test methods has been
12.2 Color Development—Add 2.5 mL of (NH ) Mo O
4 6 7 24
planned.
solution to each flask and let stand 5 min. Then add 5.0 mL of
7.2 The relative reproducibility data in Table 1 has no
H SO (1+3), mix well, and add 5 drops of SnCl solution.
2 4 2
supportive research report on file and does not conform to
Dilute to volume and let stand 5 min.
ASTM precision and bias standards.
12.3 Photometry—Transfer a suitable portion of the reagent
SILICON BY THE MOLYBDENUM BLUE TEST
blank solution to a 1-cm absorption cell and adjust the
METHOD photometertotheinitialsetting,usingawavelengthof765nm.
While maintaining this photometer adjustment, take the pho-
8. Summary of Test Method
tometric readings of the calibration solutions.
8.1 Silicomolybdic acid is formed by adding ammonium
12.4 Calibration Curve—Plot the photometric readings (ab-
molybdate to soluble silicates in acid solution. The heteropoly
sorbance) of the calibration solution against micrograms of
acid is reduced with stannous chloride to form a deep blue
silicon per 100 mL of solution.
colloidal solution. Photometric measurement is made at 765
nm. Regular classical gravimetric methods for silica using
13. Procedure for Carbonate Fusion
sodium carbonate fusion followed by hydrofluoric acid vola-
13.1 Sample Solution—Rinse the ash (from a 50 to 75-g ash
tilization may be suitable for use.
sample)fromtheplatinumdishintoamullitemortarwiththree
0.5-g portions of Na CO passing a No. 100 (150-µm) sieve
9. Stability of Color
2 3
(see Test Method C561). Grind the resulting mixture to pass a
9.1 The blue colored solution should be disposed of and the
No. 200 (75-µm) sieve to ensure intimate contact of the ash
determination repeated if a period of 12 h has elapsed between
with the flux. Then transfer the mixture to a platinum crucible
color development and measurements.
(containing 0.5 g of Na CO ) with three 0.5-g rinses of
2 3
Na CO . Add sufficient Na CO to bring the total Na CO
10. Interferences 2 3 2 3 2 3
content to 6 g. Cover the crucible, and fuse gently over a
10.1 There is no interference from the ions usually present
bunsen burner.
in graphite.
13.1.1 When fusion is complete (usually 30 min to 1 h),
removethecruciblefromtheburner,swirltodistributethemelt
11. Reagents
on the sides of the crucible, and allow to cool. Then place the
11.1 Ammonium Molybdate (50 g/L)—Dissolve 50 g of
crucible and contents in a 200-mL high-form beaker and add
ammonium molybdate ((NH ) -Mo O ·4H O) in water and
4 6 7 24 2
25 mL of water. Cover the beaker with a watch glass, and
dilute to 1 L.
cautiously add HCl (1+1) to decompose the melt. When
11.2 Hydrochloric Acid (HCl) (1+1)—Mix equal volumes solution of the melt is complete, boil for several minutes on a
of concentrated HCl, sp gr 1.19 and water. hot plate and cool.
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C560 − 88 (2010)
13.1.2 Transfer to a 100-mL volumetric flask, dilute to the iron to the ferric state. Boil the solution to expel the excess
volume, and mix. Transfer a suitable aliquot of this solution to bromine and dilute to 1 L in a volumetric flask.
a 100-mL volumetric flask.
18.6 Iron Wire, primary standard, over 99.9 % pure.
13.2 Color Development—Adjust the pH of the aliquot to 6
18.7 o-Phenanthroline—Dissolve2gof 1,10-
to 8 with Na CO solution, then proceed in accordance with
2 3
phenanthrolineinethylalcoholanddiluteto250mLwithethyl
13.2.
alcohol in a volumetric flask. Discard this solution if color
13.3 Photometry—Proceed in accordance with 12.3. develops upon long standing.
13.4 Calibration—Convert the photometric reading of the
19. Preparation of Calibration Curve
sample solution to micrograms of silicon by means of the
19.1 Calibration Solutions—Transfer 0.0, 1.0, 2.0, 3.0, 4.0,
calibration curve.
5.0, and 6.0 mLof iron solution (1 mL= 0.1 mg Fe) to 100-mL
volumetric flasks. Add NH OH (1+1) until the brown hydrous
14. Calculation
precipitate of ferric hydroxide (Fe(OH) ) is just visible. Then
14.1 Calculate the parts per million (ppm) of silicon in the
add HCl (1+1) drop-wise, while stirring, until the precipitate
original sample as follows:
just dissolves. Bring the pH of the solution to 3.0 by adding 2
Silicon, ppm ~A 3 B!/W
additional drops of HCl (1+1). Then add 2 mLof NH OH·HCl
solution.
where:
19.2 Color Development—Heat the solutions in the flasks
A = siliconper100mLofsolutionfoundinthealiquotused,
almost to boiling. Add 1 mL of o-phenanthroline solution and
µg,
allow the solutions to cool. Then dilute to the mark with water.
B = aliquot factor = original volume divided by aliquot
taken for analysis, and
19.3 Photometry—Transfer a suitable portion of the reagent
W = original sample weight, g.
blank solution to a 1-cm absorption cell, and adjust the
spectrophotometer to the initial setting using a wavelength of
IRON BY THE ORTHO-PHENANTHROLINE
490 nm. While maintaining this photometer adjustment, take
(PHOTOMETRIC) TEST METHOD
the photometric readings of the calibration solutions.
19.4 Calibration Curve—Plot the absorbance of the calibra-
15. Summary of Test Method
tion solution against micrograms of iron per 100 mL of
15.1 After suitable dilution of an aliquot from the carbonate
solution.
fusion is adjusted to a pH of 3.0, the iron is reduced with
hydroxylamine hydrochloride. The ferrous ortho-
20. Procedure
phenanthroline complex is formed, and its absorption is mea-
20.1 Sample Solution—Proceed in accordance with 13.1.
sured at a wavelength of 490 nm.
20.2 Color Development—Proceed in accordance with 19.2.
16. Stability of Color
20.3 Photometry—Proceed in accordance with 19.2.
16.1 The color becomes stable within 15 min and does not
20.4 Calibration—Convert the photometric reading of the
change for at least 48 h.
sample solution to micrograms of iron by means of the
calibration curve.
17. Interferences
21. Calculation
17.1 No interfering elements are normally present in graph-
ite. 21.1 Calculate the ppm of iron in the original sample as
follows:
18. Reagents
Fe, ppm A 3 B /W
~ !
18.1 Ammonium Hydroxide (NH OH) (1+1)—Mix equal
where:
volumes of concentrated NH OH, sp gr 0.90 and water.
A = iron per 100 mL of solution in the aliquot used, µg,
18.2 Bromine Water—Add 10 mL of bromine to 1 L of
B = aliquot factor = original volume divided by aliquot
water. Allow to stand for 24 h.
taken for analysis, and
W = original sample weight, g.
18.3 Hydrochloric Acid (HCl) (1+1)—Mix equal volumes
of concentrated HCl, sp gr 1.19 and water.
CALCIUM BY THE PERMANGANATE
18.4 Hydroxylamine Hydrochloride Solution—Dissolve 10
(COLORIMETRIC) TEST METHOD
g of hydroxylamine hydrochloride (NH OH·HCl) in water and
dilute to 100 mL. Discard the solution if color develops on 22. Summary of Test Method
standing for long periods of time.
22.1 Calcium is precipitated as the oxalate, filtered off, and
18.5 Iron, Standard Solution (1 mL = 0.1 mg Fe)—Into a dissolved in sulfuric acid.The acid solution is added to a dilute
100-mLbeaker, weigh 0.1000 g of iron wire. Dissolve the wire potassium permanganate solution, and the decrease in absorp-
in 50 mLof HCl (1+1).Add 1 mLof bromine water to oxidize tion is measured at a wavelength of 528 nm.
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C560 − 88 (2010)
23. Stability of Color allow to stand at room temperature for 5 min for the color
change to be completed. Place in a cold-water bath, and cool to
23.1 Potassium permanganate solution is decomposed rap-
room temperature. Dilute to volume with CO -free water and
idly by exposure to air or light. Photometric readings should be
mix.
made at once.
26.3 Photometry—Transfer a portion of the reagent blank
24. Interferences
solutiontoa1-cmabsorptioncell.Transferaportionofthefirst
standard into a second absorption cell. Adjust the spectr
...
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