ASTM C560-88(1998)
(Test Method)Standard Test Methods for Chemical Analysis of Graphite
Standard Test Methods for Chemical Analysis of Graphite
SCOPE
1.1 These test methods cover the chemical analysis of graphite.
1.2 The analytical procedures appear in the following order: Sections Silicon by the Molybdenum Blue (Colorimetric) Test Method 8 to 14 Iron by the o-Phenanthroline (Colorimetric) Test Method 15 to 21 Calcium by the Permanganate (Colorimetric) Test Method 22 to 28 Aluminum by the 2-Quinizarin Sulfonic Acid Test Method 29 to 35 Titanium by the Peroxide (Colorimetric) Test Method 36 to 43 Vanadium by the 3,3'-Dimethylnaphthidine (Colorimetric) Test Method 44 to 51 Boron by the Curcumin-Oxalic Acid (Colorimetric) Test Method 52 to 59
1.3 The preferred concentration of sought element in the final solution, the limits of sensitivity, and the precision of the results are given in Table 1.
1.4 This standard does not purport to address all of the safety problems, 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. See 56.1 for specific caution statement.
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An American National Standard
Designation:C 560–88 (Reapproved 1998)
Standard Test Methods for
Chemical Analysis of Graphite
This standard is issued under the fixed designation C 560; 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 (e) indicates an editorial change since the last revision or reapproval.
TABLE 1 Concentration of Elements, Limits of Sensitivity, and
1. Scope
Reproducibility
1.1 These test methods cover the chemical analysis of
graphite.
Concentration Reproducibility,
1.2 The analytical procedures appear in the following order:
Range, µg/mL Sensitivity Limit, Relative, %
Element Solution µg/mL Solution (s/x 3 100)
Sections
Silicon by the Molybdenum Blue (Colorimetric) Test Method 8 to 14 Silicon 10 to 100 µg/100 mL 1 µg/100 mL 64
Ironbythe o-Phenanthroline (Colorimetric) Test Method 15 to 21 Iron 100 to 600 µg/100 mL 40 µg/100 mL 65
Calcium by the Permanganate (Colorimetric) Test Method 22 to 28 Calcium 600 to 3000 µg/100 mL 50 µg/100 mL 65
Aluminum by the 2-Quinizarin Sulfonic Acid Test Method 29 to 35
Aluminum 10 to 100 µg/100 mL 2 µg/100 mL 60.1
Titanium by the Peroxide (Colorimetric) Test Method 36 to 43 Titanium 600 to 3000 µg/100 mL 200 µg/100 mL 62
Vanadium by the 3,38-Dimethylnaphthidine (Colorimetric) Test
Vanadium 10 to 130 µg/50 mL 5 µg/50 mL 65
Method 44 to 51 Boron 0.5 to 1.4 µg/50 mL 0.1 µg/50 mL 620
Boron by the Curcumin-Oxalic Acid (Colorimetric) Test Method 52 to 59
1.3 The preferred concentration of sought element in the
final solution, the limits of sensitivity, and the precision of the
may be incompatible with certain nuclear applications. Other
results are given in Table 1.
elemental contamination can affect the rate of oxidative deg-
1.4 This standard does not purport to address all of the
radation.
safety concerns, if any, associated with its use. It is the
3.2 Thesetestmethodsallowmeasurementoftraceamounts
responsibility of the user of this standard to establish appro-
of contaminants with a minimal amount of costly equipment.
priate safety and health practices and determine the applica-
The colorimetric procedures used are accessible to most
bility of regulatory limitations prior to use. See 56.1 for
laboratories.
specific caution statement.
4. Reagents
2. Referenced Documents
4.1 Purity of Reagents—Reagent grade chemicals shall be
2.1 ASTM Standards:
used in all tests. Unless otherwise indicated, it is intended that
C 561 Test Method for Ash in a Graphite Sample
all reagents shall conform to the specifications of the Commit-
D 1193 Specification for Reagent Water
tee onAnalytical Reagents of theAmerican Chemical Society,
E 29 Practice for Using Significant Digits in Test Data to 6
where such specifications are available. Other grades may be
Determine Conformance with Specifications
used, provided it is first ascertained that the reagent is of
E 50 Practices forApparatus, Reagents, and Safety Consid-
sufficiently high purity to permit its use without lessening the
erations for Chemical Analysis of Metals, Ores, and
accuracy of the determination.
Related Materials
4.2 When available, National Institute of Standards and
Technology (NIST) certified reagents should be used as stan-
3. Significance and Use
dards in preparing calibration curves.
3.1 These test methods provide a practical way to measure
4.3 Unless otherwise indicated, references to water shall be
the concentration of certain trace elements in graphite. Many
understood to mean reagent water conforming to Specification
end uses of graphite require that it be free of elements which
D 1193.
4.4 National Institute of Standards and Technology certified
reagents specified in certain steps of this procedure may no
These test methods are under the jurisdiction of ASTM Committee D02 on
Petroleum Products and Lubricants and are the direct responsibility of Subcommit-
tee D02.F on Manufactured Carbon and Graphite Products.
Current edition approved July 29, 1988. Published September 1988. Originally Reagent Chemicals, American Chemical Society Specifications, American
published as C 560 – 65 T. Last previous edition C 560 – 77 (1982)e . Chemical Society, Washington, DC. For suggestions on the testing of reagents not
Annual Book of ASTM Standards, Vol 05.05. listed by the American Chemical Society, see Analar Standards for Laboratory
Annual Book of ASTM Standards, Vol 11.01. Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
Annual Book of ASTM Standards, Vol 14.02. and National Formulary, U.S. Pharmaceutical Convention, Inc. (USPC), Rockville,
Annual Book of ASTM Standards, Vol 03.05. MD.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
C 560
longerbeavailable.IfNISTreagentsarenotavailable,thenthe 11.5 Sodium Carbonate Solution(100g/L)—Dissolve100g
highest purity reagent grade shall be substituted. ofsodiumcarbonate(Na CO )inwateranddiluteto1L.Store
2 3
in a polyethylene bottle.
5. Sampling
11.6 Stannous Chloride Solution—Dissolve 2.5 g of stan-
5.1 The entire sample of graphite should be crushed and
nous chloride (SnCl ·2H O) in 5 mL of hot concentrated HCl
2 2
ground to pass a No. 60 (250-µm) sieve in a roll crusher. The
(sp gr 1.19) and dilute to 250 mL with water. Prepare a fresh
sample may have been reduced in size initially by drilling the
solution every 2 weeks.
test bar with silicon carbide-tipped drills.
11.7 SulfuricAcid(H SO )(1+3)—Carefullymix1volume
2 4
of concentrated H SO , sp gr 1.84 with 3 volumes of water.
2 4
6. Rounding Calculated Values
6.1 Calculated values shall be rounded to the desired num-
12. Preparation of Calibration Curve
ber of places in accordance with Practice E 29.
12.1 Calibration Solutions—Transfer 0, 1.0, 3.0, 5.0, 7.0,
and 10 mL of silicon working solution (1 mL = 0.01 mg Si) to
7. Precision and Bias
100-mL volumetric flasks. Add 5 drops of H SO (1+3) and
2 4
7.1 No statement is being made about either the precision or
dilute to approximately 10 mL.
bias of these test methods. At this time Committee C-5 is
12.2 Color Development—Add 2.5 mL of (NH ) Mo O
4 6 7 24
investigating new standard methods of chemical analysis of
solution to each flask and let stand 5 min. Then add 5.0 mL of
graphite that will eventually replace these test methods. For
H SO (1+3), mix well, and add 5 drops of SnCl solution.
2 4 2
this reason, no statistical study of these test methods has been
Dilute to volume and let stand 5 min.
planned.
12.3 Photometry—Transfer a suitable portion of the reagent
7.2 The relative reproducibility data in Table 1 has no
blank solution to a 1-cm absorption cell and adjust the
supportive research report on file and does not conform to
photometertotheinitialsetting,usingawavelengthof765nm.
ASTM precision and bias standards.
While maintaining this photometer adjustment, take the pho-
SILICON BY THE MOLYBDENUM BLUE TEST
tometric readings of the calibration solutions.
METHOD
12.4 Calibration Curve—Plot the photometric readings (ab-
sorbance) of the calibration solution against micrograms of
8. Summary of Test Method
silicon per 100 mL of solution.
8.1 Silicomolybdic acid is formed by adding ammonium
molybdate to soluble silicates in acid solution. The heteropoly
13. Procedure for Carbonate Fusion
acid is reduced with stannous chloride to form a deep blue
13.1 Sample Solution—Rinse the ash (from a 50 to 75-g ash
colloidal solution. Photometric measurement is made at 765
sample) from the platinum dish into a mullite mortar with three
nm. Regular classical gravimetric methods for silica using
0.5-g portions of Na CO passing a No. 100 (150-µm) sieve
2 3
sodium carbonate fusion followed by hydrofluoric acid vola-
(see Test Method C 561). Grind the resulting mixture to pass a
tilization may be suitable for use.
No. 200 (75-µm) sieve to ensure intimate contact of the ash
with the flux. Then transfer the mixture to a platinum crucible
9. Stability of Color
(containing 0.5 g of Na CO ) with three 0.5-g rinses of Na
2 3
9.1 The blue colored solution should be disposed of and the
2CO .AddsufficientNa CO tobringthetotalNa CO content
3 2 3 2 3
determination repeated if a period of 12 h has elapsed between
to 6 g. Cover the crucible, and fuse gently over a bunsen
color development and measurements.
burner.
13.1.1 When fusion is complete (usually 30 min to 1 h),
10. Interferences
removethecruciblefromtheburner,swirltodistributethemelt
10.1 There is no interference from the ions usually present
on the sides of the crucible, and allow to cool. Then place the
in graphite.
crucible and contents in a 200-mL high-form beaker and add
25 mL of water. Cover the beaker with a watch glass, and
11. Reagents
cautiously add HCl (1+1) to decompose the melt. When
11.1 Ammonium Molybdate (50 g/L)—Dissolve 50 g of
solution of the melt is complete, boil for several minutes on a
ammonium molybdate ((NH ) -Mo O ·4H O) in water and
4 6 7 24 2
hot plate and cool.
dilute to 1 L.
13.1.2 Transfer to a 100-mL volumetric flask, dilute to
11.2 Hydrochloric Acid (HCl) (1+1)—Mix equal volumes
volume, and mix. Transfer a suitable aliquot of this solution to
of concentrated HCl, sp gr 1.19 and water.
a 100-mL volumetric flask.
11.3 Silicon, Standard Solution(1mL=1mgSi)—Dissolve
13.2 Color Development—Adjust the pH of the aliquot to 6
10.1 g of sodium silicate (Na SiO ·9H O) in water and dilute
2 3 2
to 8 with Na CO solution, then proceed in accordance with
to 1 L in a volumetric flask. Store in a polyethylene bottle. 2 3
13.2.
Determine exact concentration by the standard gravimetric
13.3 Photometry—Proceed in accordance with 12.3.
procedure.
11.4 Silicon, Working Solution(1mL=0.01mgSi)—Dilute 13.4 Calibration—Convert the photometric reading of the
10 mL of standard silicon solution (1 mL = mg Si) to 1 L in a sample solution to micrograms of silicon by means of the
volumetric flask. Transfer to a polyethylene bottle. calibration curve.
C 560
14. Calculation just dissolves. Bring the pH of the solution to 3.0 by adding 2
additional drops of HCl (1+1). Then add 2 mLof NH OH·HCl
14.1 Calculate the parts per million of silicon in the original
solution.
sample as follows:
19.2 Color Development—Heat the solutions in the flasks
Silicon, ppm ~A 3 B!/W
almost to boiling. Add 1 mL of o-phenanthroline solution and
allow the solutions to cool. Then dilute to the mark with water.
where:
19.3 Photometry—Transfer a suitable portion of the reagent
A = silicon per 100 mL of solution found in the aliquot
blank solution to a 1-cm absorption cell, and adjust the
used, µg,
spectrophotometer to the initial setting using a wavelength of
B = aliquot factor = original volume divided by aliquot
taken for analysis, and 490 nm. While maintaining this photometer adjustment, take
W = original sample weight, g. the photometric readings of the calibration solutions.
19.4 Calibration Curve—Plot the absorbance of the calibra-
IRON BY THE ORTHO-PHENANTHROLINE
tion solution against micrograms of iron per 100 mL of
(PHOTOMETRIC) TEST METHOD
solution.
15. Summary of Test Method
20. Procedure
15.1 After suitable dilution of an aliquot from the carbonate
20.1 Sample Solution—Proceed in accordance with 13.1.
fusion is adjusted to a pH of 3.0, the iron is reduced with
20.2 ColorDevelopment—Proceedinaccordancewith19.2.
hydroxylamine hydrochloride. The ferrous ortho-
20.3 Photometry—Proceed in accordance with 19.2.
phenanthroline complex is formed, and its absorption is mea-
20.4 Calibration—Convert the photometric reading of the
sured at a wavelength of 490 nm.
sample solution to micrograms of iron by means of the
calibration curve.
16. Stability of Color
21. Calculation
16.1 The color becomes stable within 15 min and does not
change for at least 48 h.
21.1 Calculate the parts per million of iron in the original
sample as follows:
17. Interferences
Fe, ppm ~A 3 B!/W
17.1 No interfering elements are normally present in graph-
where:
ite.
A = iron per 100 mL of solution in the aliquot used, µg,
B = aliquot factor = original volume divided by aliquot
18. Reagents
taken for analysis, and
18.1 Ammonium Hydroxide (NH OH) (1+1)—Mix equal
W = original sample weight, g.
volumes of concentrated NH OH, sp gr 0.90 and water.
18.2 Bromine Water—Add 10 mL of bromine to 1 L of
CALCIUM BY THE PERMANGANATE
water. Allow to stand for 24 h.
(COLORIMETRIC) TEST METHOD
18.3 Hydrochloric Acid (HCl) (1+1)—Mix equal volumes
of concentrated HCl, sp gr 1.19 and water.
22. Summary of Test Method
18.4 Hydroxylamine Hydrochloride Solution—Dissolve 10
22.1 Calcium is precipitated as the oxalate, filtered off, and
g of hydroxylamine hydrochloride (NH OH·HCl) in water and
dissolved in sulfuric acid.The acid solution is added to a dilute
dilute to 100 mL. Discard the solution if color develops on
potassium permanganate solution, and the decrease in absorp-
standing for long periods of time.
tion is measured at a wavelength of 528 nm.
18.5 Iron, Standard Solution (1 mL = 0.1 mg Fe)—Into a
100-mLbeaker, weigh 0.1000 g of iron wire. Dissolve the wire
23. Stability of Color
in 50 mLof HCl (1+1).Add 1 mLof bromine water to oxidize
23.1 Potassium permanganate solution is decomposed rap-
the iron to the ferric state. Boil the solution to expel the excess
idly by exposure to air or light. Photometric readings should be
bromine and dilute to 1 L in a volumetric flask.
made at once.
18.6 Iron Wire, primary standard, over 99.9 % pure.
18.7 o-Phenanthroline—Dissolve2gof 1,10-
24. Interferences
phenanthrolineinethylalcoholanddiluteto250mLwithethyl
alcohol in a volumetric flask. Discard this solution if color 24.1 Ashedgraphitesamplesarenormallyfreeofsignificant
develops upon long standing. concentrations of possible interfering ions.
19. Preparation of Calibration Curve 25. Reagents
19.1 Calibration Solutions—Transfer 0.0, 1.0, 2.0, 3.0, 4.0, 25.1 Ammonium Hydroxide (NH OH ) (1+6)—Mix 1 vol-
4 2
5.0, and 6.0 mLof iron solution (1 mL= 0.1 mg Fe) to 100-mL ume of concentrated NH OH , sp gr 0.90 with 6 volumes of
4 2
volumetric flasks. Add NH OH (1+1) until the brown hydrous water.
precipitate of ferric hydroxide (Fe(OH) ) is just visible. Then 25.2 Ammonium Oxalate Solution—Prepare a saturated so-
add HCl (1+1) drop-wise, while stirring, until the precipitate lution of ammonium oxalate ((NH ) C O ·2H O).
4 2 2 4 2
C 560
25.3 Bromocresol Green Indicator Solution—Use the water green indicator, 1 mL of formate buffer, and 1 mL of saturated
solublesodiumsalt.Dissolve0.040ginwateranddiluteto100 (NH ) C O solution. Ad
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