1、Designation: C1284 10Standard 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 revisio
2、n. 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 ac-tinide fractions for alpha spectrometry measurement.2It isapplicable to any o
3、f the actinides that can be dissolved in diluteammonium sulfate solution. Examples of applicable actinidefractions would be the final elution from an ion exchangeseparation or the final strip from a solvent extraction separa-tion.1.2 The values stated in SI units are to be regarded asstandard. No ot
4、her units of measurement are included in thisstandard.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility
5、of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:3C1163 Practice for Mounting Actinides for Alpha Spec-trometry Using Neodymium FluorideD1193 Specification for Reagent Water3. Summary of Practice3.1 Guidance is provided for the electrodeposition of sepa-rated actinide
6、 fractions onto metal discs. This practice is basedon cathodic deposition of the hydrated oxides of the actinidesfrom an acidic medium containing an ammonium salt. Theresultant electrodeposited samples are suitable for alpha spec-trometry measurements.4. Significance and Use4.1 The determination of
7、actinide elements by alpha spec-trometry measurement is an essential part of many environ-mental research, bioassay, and monitoring programs. Alphaspectrometry measurements identify and quantify the alpha-emitting actinide elements. A variety of separation methodswill typically precede the electrode
8、position of a sample foralpha spectrometry measurements. In addition to the elec-trodeposition procedure presented in this practice, the scientificliterature contains other procedures for actinide electrodeposi-tion.NOTE 1An alternate method for mounting actinides for alpha spec-trometry measurement
9、s by coprecipitation with neodymium fluoride isdescribed in Practice C1163.5. Interferences5.1 Any element present in the separated fraction which iscapable of cathodic electrodeposition will be present on themetal disc. In particular210Po (5.30 MeV) deposited on thedisc would interfere with the yie
10、ld determination of232U (5.32MeV) or243Am (5.28 MeV) tracers used in the determinationof isotopic uranium and241Am (5.15 MeV), respectively.5.2 Incomplete separation of rare earth elements or incom-plete wet ashing for the removal of organic material willdecrease the efficiency of the electrodeposit
11、ion and may resultin a thick deposit unsuitable for alpha spectrometry measure-ment.5.3 The quantity of actinide should be such that 5 g cm2are electrodeposited on the metal disc. Thicker deposits aretypically unsuitable for measurement by alpha spectrometrydue to the resulting attenuation and decre
12、ase in energy resolu-tion.6. Apparatus6.1 Electrodeposition Power SupplyConstant current, ad-justable from 0 to 2 A with indicating meter.6.2 Electrodeposition CellDisposable cells are recom-mended. The cells should have a minimum volume capacity of25 mL.6.3 Metal DiscsStainless steel disc, or other
13、 metal discsuch as platinum, polished to a mirror finish on one side. Thediameter of the disc is determined by diameter of the elec-trodeposition cell. The current density should be approximately0.5Acm2of the disc area.6.4 Electrodeposition AnodeThe exact dimensions of theanode will be determined by
14、 the cross-sectional area and depthof the electrodeposition cell. For example, a 1.5 mm diameter1This practice is under the jurisdiction of ASTM Committee C26 on NuclearFuel Cycle and is the direct responsibility of Subcommittee C26.05 on Methods ofTest.Current edition approved June 1, 2010. Publish
15、ed July 2010. Originally approvedin 1994. Last previous edition approved in 2005 as C1284 - 00 (2005). DOI:10.1520/C1284-10.2Based on Talvitie, N. A., “Electrodeposition of Actinides for Alpha Spectro-metric Determination,” Analytical Chemistry, Vol 44, 1972, pp. 280283.3For referenced ASTM standard
16、s, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 1
17、9428-2959, United States.by 100 mm long platinum wire with loop facing the cathode(stainless steel disc). The anode loop should be just slightlysmaller than the cathode.6.5 Insulated Base, to support the cell and provide thecathode connection.7. Reagents7.1 Purity of ReagentsReagent grade chemicals
18、must beused in all procedures. Unless otherwise noted, all reagentsshould conform to the specifications of the Committee onAnalytical Reagents of the American Chemical Society,4ifsuch specifications are available. Other grades of reagents maybe used if it is ascertained by the user that the reagent
19、is ofsufficiently high purity to permit its use without reducing theaccuracy of the determination. All reagents should be stored inplastic bottles.7.2 Reagent BlanksReagent blanks should be analyzed todetermine their contribution to the sample result. The analysisof reagent blanks as part of the ove
20、rall analytical methodshould be considered.7.3 Purity of WaterUnless otherwise indicated, water isdefined as reagent water as described in Specification D1193,Type III.7.4 Ammonium Hydroxide (sp gr 0.90)Concentrated am-monium hydroxide (15 M NH4OH).7.5 Ammonium Sulfate Solution (1 M)Dissolve 132 g o
21、f(NH4)2SO4in water and dilute to 1 L.7.6 Electrolyte Solution1 M (NH4)2SO4solution adjustedto pH 3.5 with concentrated H2SO4and concentrated NH4OH.7.7 Ethyl Alcohol Solution95 %.7.8 Nitric Acid (sp gr 1.42)Concentrated nitric acid (16 MHNO3).7.9 Sodium Hydrogen Sulfate (0.36 M in1MH2SO4)Dissolve 10
22、g of NaHSO4H2O in 88 mL of water and add 112mL of 1.8 M H2SO4.7.10 Sulfuric Acid (1.8 M)Mix 100 mL of concentratedsulfuric acid with water and dilute to 1 L.8. Precautions8.1 Adequate laboratory facilities such as fume hoods andcontrolled ventilation, along with safe techniques must be usedin perfor
23、ming this procedure. Use of safety glasses or gogglesis recommended.8.2 The electrodeposition cell should be tested for leaksprior to use.9. Electrodeposition Procedure9.1 Add 2 mL of 0.36 M NaHSO4in 1 M H2SO4to theseparated actinide fraction in the beaker. Add 5 mL ofconcentrated HNO3to the beaker,
24、 swirl to mix, and evaporatethe solution to dryness but do not bake.9.2 Add 5 mLof electrolyte solution to the beaker and warmto dissolve the residue.9.3 Transfer the sample solution to the electrodepositioncell. Rinse the beaker with 5 to 10 mL of electrolyte solutionand add the rinsings to the ele
25、ctrodeposition cell. Add pHindicator and adjust the pH.9.4 Connect the cathode () to base of the electrodepositioncell.9.5 Lower the platinum anode ( + ) to about 1 cm above thestainless steel disc in the electrodeposition cell.9.6 Turn on the power supply and, for a 2.5 cm metal disc,adjust the cur
26、rent to 1.2 A. Electrodeposit at a constant currentfor2h.9.7 After 2 h, add 1 mL of concentrated NH4OH to the celland continue to electrodeposit for 1 min.9.8 Turn off the current and remove the anode. Empty anddiscard the electrolyte solution.9.9 Disassemble the cell and rinse the disc with ethylal
27、cohol solution. Touch the edge of the disc with a tissue toabsorb the excess alcohol.9.10 Place the disc on a 200 to 250C hot plate to dry andfix the electrodeposited species. Air drying of the electroplateddisc has also been successfully used.9.11 Submit the sample for alpha spectrometry measure-me
28、nt.10. Keywords10.1 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
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33、4Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, see Analar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.C1284 102
