1、Designation: C1284 10C1284 18Standard Practice forElectrodeposition of the Actinides for Alpha Spectrometry1This standard is issued under the fixed designation C1284; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last
2、 revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice covers the preparation of separated actinide fractions for alpha spectrometry measurement.2 It is applicable
3、 toany of the actinides that can be dissolved in dilute ammonium sulfate solution. Examples of applicable actinide fractions wouldbe the final an elution from an ion exchange / extraction chromatography separation or the final strip from a solvent extractionseparation.1.2 The values stated in SI uni
4、ts are to be regarded as standard. No other units of measurement are included in this standard.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety safety, healt
5、h, and healthenvironmental practices and determine theapplicability of regulatory limitations prior to use.1.4 This international standard was developed in accordance with internationally recognized principles on standardizationestablished in the Decision on Principles for the Development of Interna
6、tional Standards, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:3C859 Terminology Relating to Nuclear MaterialsC1163 Practice for Mounting Actinides for Alpha Spectrometry Using Neodymium Fluorid
7、eD1193 Specification for Reagent Water3. Terminology3.1 Except as otherwise defined herein, definitions of terms are as given in Terminology C859.4. Summary of Practice4.1 Guidance is provided for the electrodeposition of separated actinide fractions onto metal discs. This practice is based oncathod
8、ic deposition of the hydrated oxides of the actinides from an acidic medium containing an ammonium salt. The resultantelectrodeposited samples are suitable for alpha spectrometry measurements.5. Significance and Use5.1 The determination of actinide elements by alpha spectrometry measurement is an es
9、sential part of many environmentalresearch, bioassay, and monitoring programs. Alpha spectrometry measurements identify and quantify the alpha-emitting actinideelements. A variety of separation methods will typically precede the electrodeposition of a sample for alpha spectrometrymeasurements. In ad
10、dition to the electrodeposition procedure presented in this practice, the scientific literature contains otherprocedures for actinide electrodeposition.NOTE 1An alternate method for mounting actinides for alpha spectrometry measurements by coprecipitation with neodymium fluoride is describedin Pract
11、ice C1163.1 This practice is under the jurisdiction of ASTM Committee C26 on Nuclear Fuel Cycle and is the direct responsibility of Subcommittee C26.05 on Methods of Test.Current edition approved June 1, 2010June 1, 2018. Published July 2010July 2018. Originally approved in 1994. Last previous editi
12、on approved in 20052010 as C1284 - 00(2005).C1284 10. DOI: 10.1520/C1284-10.10.1520/C1284-18.2 Based on Talvitie, N. A., “Electrodeposition of Actinides for Alpha Spectrometric Determination,” Analytical Chemistry, Vol 44, 1972, pp. 280283.3 For referencedASTM standards, visit theASTM website, www.a
13、stm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what
14、changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the o
15、fficial document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States16. Interferences6.1 Any element present in the separated fraction which is capable of cathodic electrodeposition will be present on the metaldisc. In particular 210Po (5
16、.30 MeV) deposited on the disc would interfere with the yield determination of 232U (5.32 MeV) or243Am (5.28 MeV) tracers used in the determination of isotopic uranium and 241Am (5.15 MeV), respectively.6.2 Incomplete separation of rare earth elements or incomplete wet ashing for the removal of orga
17、nic material will decrease theefficiency of the electrodeposition and may result in a thick deposit unsuitable for alpha spectrometry measurement.6.3 The quantity of actinide should be such that 5 g cm2 are electrodeposited on the metal disc.Thicker deposits are typicallyunsuitable for measurement b
18、y alpha spectrometry due to the resulting attenuation and decrease in energy resolution.7. Apparatus7.1 Electrodeposition Power SupplyConstant current, adjustable from 0 to 2 A with indicating meter.7.2 Electrodeposition CellDisposable cells are recommended. The cells should have a minimum volume ca
19、pacity of 25 mL.7.3 Metal DiscsStainless steel disc, or other metal disc such as platinum, polished to a mirror finish on one side. The diameterof the disc is determined by diameter of the electrodeposition cell. The current density should be approximately 0.5 A cm2 of thedisc area.7.4 Electrodeposi
20、tion AnodeThe exact dimensions of the anode will be determined by the cross-sectional area and depth ofthe electrodeposition cell. For example, a 1.5 mm diameter by 100 mm long platinum wire with loop facing the cathode (stainlesssteel disc). The anode loop should be just slightly smaller than the c
21、athode.7.5 Insulated Base, to support the cell and provide the cathode connection.8. Reagents8.1 Purity of ReagentsReagent grade chemicals must be used in all procedures. Unless otherwise noted, all reagents shouldconform to the specifications of the Committee on Analytical Reagents of the American
22、Chemical Society,4 if such specificationsare available. Other grades of reagents may be used if it is ascertained by the user that the reagent is of sufficiently high purityto permit its use without reducing the accuracy of the determination. All reagents should be stored in plastic bottles.8.2 Reag
23、ent BlanksReagent blanks should be analyzed to determine their contribution to the sample result. The analysis ofreagent blanks as part of the overall analytical method should be considered.8.3 Purity of WaterUnless otherwise indicated, water is defined as reagent water as described in Specification
24、 D1193, TypeIII.8.4 Ammonium Hydroxide (sp gr 0.90)Concentrated ammonium hydroxide (15 M NH4OH).8.5 Ammonium Sulfate Solution (1 M)Dissolve 132 g of (NH4)2SO4 in water and dilute to 1 L.8.6 Electrolyte Solution1 M (NH4)2SO4 solution adjusted to pH 3.5 with concentrated H2SO4 and concentrated NH4OH.8
25、.7 Ethyl Alcohol Solution95 %.8.8 Nitric Acid (sp gr 1.42)Concentrated nitric acid (16 M HNO3).8.9 Sodium Hydrogen Sulfate (0.36 M in 1 M H2SO4)Dissolve 10 g of NaHSO4H2O in 88 mL of water and add 112 mL of1.8 M H2SO4.8.10 Sulfuric Acid (1.8 M)Mix 100 mL of concentrated sulfuric acid with water and
26、dilute to 1 L.9. Precautions9.1 Adequate laboratory facilities such as fume hoods and controlled ventilation, along with safe techniques must be used inperforming this procedure. Use of safety glasses or goggles is recommended.9.2 The electrodeposition cell should be tested for leaks prior to use.10
27、. Electrodeposition Procedure10.1 Add 2 mL of 0.36 M NaHSO4 in 1 M H2SO4 to the separated actinide fraction in the beaker. Add 5 mL of concentratedHNO3 to the beaker, swirl to mix, and evaporate the solution to dryness but do not bake.10.2 Add 5 mL of electrolyte solution to the beaker and warm to d
28、issolve the residue.4 Reagent Chemicals, American Chemical Society Specifications, American Chemical Society, Washington, DC. For suggestions on the testing of reagents not listed bythe American Chemical Society, see Analar Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and the U
29、nited States Pharmacopeia and NationalFormulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, MD.C1284 18210.3 Transfer the sample solution to the electrodeposition cell. Rinse the beaker with 5 to 10 mL of electrolyte solution and addthe rinsings to the electrodeposition cell. Add pH indi
30、cator and adjust the pH.10.4 Connect the cathode () to base of the electrodeposition cell.10.5 Lower the platinum anode ( + ) to about 1 cm above the stainless steel disc in the electrodeposition cell.10.6 Turn on the power supply and, for a 2.5 cm metal disc, adjust the current to 1.2 A. Electrodep
31、osit at a constant current for2 h.10.7 After 2 h, add 1 mL of concentrated NH4OH to the cell and continue to electrodeposit for 1 min.10.8 Turn off the current and remove the anode. Empty and discard the electrolyte solution.10.9 Disassemble the cell and rinse the disc with ethyl alcohol solution. T
32、ouch the edge of the disc with a tissue to absorb theexcess alcohol.10.10 Place the disc on a 200 to 250C hot plate to dry and fix the electrodeposited species.Air drying of the electroplated dischas also been successfully used.10.11 Submit the sample for alpha spectrometry measurement.11. Keywords1
33、1.1 actinides; alpha spectrometry; electrodepositionASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rig
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