ASTM C760-90(1996)
(Test Method)Standard Test Methods for Chemical and Spectrochemical Analysis of Nuclear-Grade Silver-Indium-Cadmium Alloys
Standard Test Methods for Chemical and Spectrochemical Analysis of Nuclear-Grade Silver-Indium-Cadmium Alloys
SCOPE
1.1 These test methods cover procedures for the chemical and spectrochemical analysis of nuclear grade silver-indium-cadmium (Ag-In-Cd) alloys to determine compliance with specifications.
1.2 The analytical procedures appear in the following order: Sections Silver, Indium, and Cadmium by a Titration Method 7 to 15 Trace Impurities by Carrier-Distillation Spectro- 16 to 22 chemical Method
1.3 The values stated in SI units are to be regarded as the standard.
1.4 This standard may involve hazardous materials, operations, and equipment. This standard does not purport to address all of 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. For specific hazard and precautionary statements, see Section 5 and Practices E50.
General Information
Relations
Standards Content (Sample)
Designation: C 760 – 90 (Reapproved 1996)
Standard Test Methods for
Chemical and Spectrochemical Analysis of Nuclear-Grade
Silver-Indium-Cadmium Alloys
This standard is issued under the fixed designation C 760; 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.
1. Scope the material must meet the specifications for assay and impu-
rity content. These test methods are designed to show whether
1.1 These test methods cover procedures for the chemical
or not a given material meets the specifications as given in
and spectrochemical analysis of nuclear grade silver-indium-
Specification C 752.
cadmium (Ag-In-Cd) alloys to determine compliance with
3.1.1 An assay is performed to determine whether the
specifications.
material has the chemical composition specified.
1.2 The analytical procedures appear in the following order:
3.1.2 The impurity content is determined to ensure that the
Sections
maximum concentration limit of impurities is not exceeded.
Silver, Indium, and Cadmium by a Titration Method 7-15
Trace Impurities by Carrier-Distillation Spectro- 16-22
chemical Method
4. Purity of Reagents
1.3 The values stated in SI units are to be regarded as the 4.1 Reagent grade chemicals shall be used in all tests.
standard. Unless otherwise indicated, it is intended that all reagents shall
1.4 This standard does not purport to address all of the conform to the specifications of the Committee on Analytical
safety concerns, if any, associated with its use. It is the Reagents of the American Chemical Society, where such
responsibility of the user of this standard to establish appro- specifications are available. Other grades may be used, pro-
priate safety and health practices and determine the applica- vided it is first ascertained that the reagent is of sufficiently
bility of regulatory limitations prior to use. For specific hazard high purity to permit its use without lessening the accuracy of
and precautionary statements, see Section 5 and Practices E 50. the determination.
4.2 Purity of Water—Unless otherwise indicated, references
2. Referenced Documents
to water shall be understood to mean reagent water conforming
2.1 ASTM Standards:
to Specification D 1193.
C 752 Specification for Nuclear-Grade Silver-
5. Hazards
IndiumCadmium Alloy
D 1193 Specification for Reagent Water
5.1 Proper precautions should be taken to prevent inhalation
E 50 Practices for Apparatus, Reagents, and Safety Precau- or ingestion of heavy element (silver, indium, or cadmium)
tions for Chemical Analysis of Metals
powder or dust during handling.
E 115 Practice for Photographic Processing in Optical 5.2 Workers should observe precautions as specified in
Emission Spectrographic Analysis vendor-supplied Material Safety Data Sheets (MSDS).
2.2 Other Document:
5 6. Sampling
NBS Circular 602
6.1 Suggestions for sampling this alloy are given in Speci-
3. Significance and Use
fication C 752.
3.1 Silver-indium-cadmium alloy is used as a control mate-
SILVER, INDIUM, AND CADMIUM BY A TITRATION
rial in nuclear reactors. In order to be suitable for this purpose,
METHOD
7. Scope
These test methods are under the jurisdiction of ASTM Committee C26 on
Nuclear Fuel Cycle and are the direct responsibility of Subcommittee C26.03 on
7.1 This test method is applicable to the determination of
Neuron Absorber Materials.
Current edition approved May 25, 1990. Published July 1990. Originally
published as C 760 – 71. Last previous edition C 760 – 79.
2 6
Annual Book of ASTM Standards, Vol 12.01. “Reagent Chemicals, American Chemical Society Specifications,” Am. Chemi-
Annual Book of ASTM Standards, Vol 11.01. cal Soc. Washington, DC. For suggestions on the testing of reagents not listed by the
Annual Book of ASTM Standards, Vol 03.05. American Chemical Society, see “Reagent Chemicals and Standards,” by Joseph
Available from National Institute of Standards and Technology, Gaithersburg, Rosin, D. Van Nostrand Co., Inc., New York, NY, and the “United States
MD 20899. Pharmacopeia.”
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
C 760
silver, indium, and cadmium in alloys of approximately 80 % 11.8 Silver (Ag)—Metal, >99.99 % pure.
silver, 15 % indium, and 5 % cadmium used in nuclear reactor 11.9 Sodium Chloride (NaCl).
7,8
control rod applications. The titrimetric methods presented 11.10 Sodium Chloride Solution (0.0500 M)—Dry sodium
will yield results with a bias of the order of 0.1 %. chloride (NaCl) at 120°C, in a weighing bottle, to a constant
weight and cool to room temperature in a desiccator. Weigh
8. Summary of Test Method
2.922 6 0.001 g of the dried NaCl into a small plastic beaker.
Dissolve in water, quantitatively transfer to a 1-L volumetric
8.1 A weighed sample is dissolved in nitric acid and diluted
flask, and make up to volume with water.
to a known volume, and aliquots are removed for analysis.
Silver is determined first by titrating with standardized sodium
12. Standardization
chloride solution to the potentiometric endpoint indicated by a
12.1 Silver-Indium-Cadmium Calibration Standard:
chloride-selective ion electrode. Following the silver titration,
12.1.1 Clean approximately 8.0 g of silver metal, 1.5 g of
the solution is boiled to coagulate the silver chloride. The pH
indium metal, and 0.5 g of cadmium metal with an organic
is adjusted to 2.5 and the indium content is titrated with EDTA,
solvent and air dry.
using PAN (1-(2-pyridylazo)-2-naphthol) indicator. The pH is
12.1.2 Weigh each metal accurately and transfer to a
then raised to 6.0 and the cadmium is titrated with EDTA using
100-mL beaker.
the same indicator. The entire process requires approximately
12.1.3 Add sufficient water to cover the metal pieces and
20 min per aliquot, exclusive of sample weighing and disso-
add HNO (sp gr 1.42) dropwise until dissolution is complete.
lution. 3
12.1.4 Transfer quantitatively to a 100-mL volumetric flask
9. Interferences and dilute to volume with water.
12.2 Calibration of NaCl and EDTA Titrants:
9.1 No interferences have been observed from any elements
12.2.1 Pipet 10 mL of the calibration standard into a
normally encountered as impurities in nuclear grade silver-
100-mL volumetric flask and dilute to volume with water.
indium-cadmium alloy over the concentration ranges expected.
(Retain this solution as a working standard.)
12.2.2 Pipet 10 mL of the diluted standard into a 100-mL
10. Apparatus
beaker and adjust the volume to about 25 mL with water.
10.1 Burets, precision, two, 25-mL capacity, preferably
12.2.3 Adjust the pH to approximately 1 using NH OH (sp
Schellbach type with TFE-fluorocarbon stopcock and auto-
gr 0.90).
matic zero. They shall be certified or tested to conform with
12.2.4 Place a TFE-fluorocarbon-coated stirring bar in the
tolerances specified in NBS Circular 602.
solution and insert the chloride specific ion electrode and the
10.2 Reference Electrode—Saturated calomel electrode.
reference electrode.
10.3 Glass pH Electrode—Standard type.
12.2.5 Stir at a moderate rate and titrate the silver with NaCl
10.4 Chloride Specific Ion Electrode.
solution. Record millivolt readings versus volume added.
10.5 Expanded Scale pH/millivolt Meter.
Allow sufficient time for equilibrium readings to be attained.
12.2.6 The titration end point is taken as the termination of
11. Reagents
the rapidly rising segment of the millivolt versus volume
11.1 Ammonium Hydroxide (sp gr 0.90)—Concentrated am-
titration curve.
monium hydroxide (NH OH).
12.2.7 Adjust to pH 2.5 6 0.2 by dropwise addition of
11.2 Buffer Solution, pH4—0.5 M sodium acetate—0.5 M
acetate buffer solution (pH4).
acetic acid.
12.2.8 Remove the electrodes and rinse thoroughly to avoid
11.3 Cadmium (Cd)—Metal, >99.99 % pure.
loss of indium and cadmium.
11.4 Ethylenediaminetetraacetate Dihydrate Disodium Salt
12.2.9 Heat the solution to boiling on a hotplate until the
(EDTA) Solution (0.01000 M)—Weigh 3.722 6 0.001 g of
supernatant liquid is clear. Allow to cool.
EDTA into a small plastic beaker. Dissolve with water, transfer
12.2.10 Add 4 drops of PAN indicator solution. The solution
quantitatively to a 1-L volumetric flask, and make up to volume
should be deep purple.
with water. Transfer the solution to a plastic storage bottle. Do
12.2.11 Titrate the indium with standard EDTA solution to
not allow the EDTA solution to stand in contact with glass
the sharp transition from purple to yellow. The volume used
containers.
corresponds to the indium content.
11.5 Indium (In)—Metal, >99.99 % pure.
12.2.12 Adjust to pH 6 6 0.2 with NH OH (sp gr 0.90). The
11.6 Nitric Acid (sp gr 1.42)—Concentrated nitric acid
color of the solution will change back to purple.
(HNO ).
12.2.13 Titrate the purple solution with standard EDTA until
11.7 PAN Indicator Solution (0.1 % PAN in Methanol)—
the color again changes to yellow. The volume used corre-
Dissolve 100 mg of 1-(2-pyridylazo)-2-naphthol in 100 mL of
sponds to the cadmium content.
methyl alcohol and mix until completely dissolved.
13. Procedure
13.1 Clean approximately 1.0 g of the sample with an
Cheng, K. L., “Complexometric Titration of Indium,” Analytical Chemistry,
organic solvent and air dry.
Vol 27, 1955, p. 1582.
8 13.2 Weigh the cleaned sample accurately and transfer it to
Cheng, K. L., “Complexometric Titration of Copper and Other Metals in a
Mixture,” Analytical Chemistry, Vol 30, 1958, p. 243. a 100-mL beaker.
C 760
13.3 Cover the sample with water and add HNO (sp gr and the spectral lines of interest are compared visually with
1.
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.