1、Designation: C 1284 00 (Reapproved 2005)Standard Practice forElectrodeposition of the Actinides for Alpha Spectrometry1This standard is issued under the fixed designation C 1284; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the
2、year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) 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
3、isapplicable to any of 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 This standard does not purport to address all
4、 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 of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:3C 1163 Test Methods f
5、or Mounting Actinides for AlphaSpectrometry Using Neodymium FluorideD 1193 Specification for Reagent Water3. Summary of Practice3.1 Guidance is provided for the electrodeposition of sepa-rated actinide fractions onto metal discs. This practice is basedon cathodic deposition of the hydrated oxides of
6、 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 actinide elements by alpha spec-trometry measurement is an essential part of many environ-mental re
7、search and monitoring programs. Alpha spectrometrymeasurements identify and quantify the alpha-emitting actinideelements. A variety of separation methods will typicallypreceed the electrodeposition of a sample for alpha spectrom-etry measurements. In addition to the electrodeposition proce-dure pres
8、ented in this practice, the scientific literature containsother procedures for actinide electrodeposition.NOTE 1An alternate method for mounting actinides for alpha spec-trometry measurements by coprecipitation with neodymium fluoride isdescribed in Test Methods C 1163.5. Interferences5.1 Any elemen
9、t 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 yield determination of232U (5.32MeV) or243Am (5.28 MeV) tracers used in the determinationof isotopic uranium
10、 and241Am, 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 electrodeposition and may resultin a thick deposit unsuitable for alpha spectrometry measure-ment.5.3 The quantity of actinide sho
11、uld 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 decrease in energy resolu-tion.6. Apparatus6.1 Electrodeposition Power SupplyConstant current, ad-justable from 0 to 2 A
12、with indicating meter.6.2 Electrodeposition CellDisposable cells are recom-mended. The cells should have a minimum volume capacity of25 mL.6.3 Metal Discs Stainless steel disc, or other metal discsuch as platinum, polished to a mirror finish on one side. Thediameter of the disc is determined by diam
13、eter 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 the cross-sectional area and depthof the electrodeposition cell. For example, a 1.5 mm diameter1This practice is un
14、der 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, 2005. Published December 2005. Originallyapproved in 1994. Last previous edition approved in 2000 as C 1284-00.2Based on Talvitie
15、, N. A., “Electrodeposition of Actinides for Alpha Spectro-metric Determination,” Analytical Chemistry, Vol 44, 1972, pp. 280283.3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume informati
16、on, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.by 100 mm long platinum wire with loop facing the cathode(stainless steel disc). The anode loop should be just slight
17、lysmaller than the cathode.6.5 Insulated Base, to support the cell and provide thecathode connection.7. Reagents7.1 Purity of ReagentsReagent grade chemicals must beused in all procedures. Unless otherwise noted, all reagentsshould conform to the specifications of the Committee onAnalytical Reagents
18、 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 is ofsufficiently high purity to permit its use without reducing theaccuracy of the determination. All reagents should be stored inplastic bot
19、tles.7.2 Reagent Blanks Reagent blanks should be analyzed todetermine their contribution to the sample result. The analysisof reagent blanks as part of the overall analytical methodshould be considered.7.3 Purity of Water Unless otherwise indicated, water isdefined as reagent water as described in S
20、pecification D 1193,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 of(NH4)2SO4in water and dilute to 1 L.7.6 Electrolyte Solution1 M (NH4)2SO4solution adjustedto pH 3.5 with concentrated H2SO4and concentrate
21、d 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 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
22、and dilute to 1 L.8. Precautions8.1 Adequate laboratory facilities such as fume hoods andcontrolled ventilation, along with safe techniques must be usedin performing this procedure. Use of safety glasses or gogglesis recommended.8.2 The electrodeposition cell should be tested for leaksprior to use.9
23、. 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, 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 t
24、he 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 electrodeposition cell.9.4 Connect the cathode () to base of the electrodepositioncell.9.5 Lower the platinum anode ( + ) to about 1 cm above
25、thestainless steel disc in the electrodeposition cell.9.6 Turn on the power supply and, for a 2.5 cm metal disc,adjust the current 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 cu
26、rrent and remove the anode. Empty anddiscard the electrolyte solution.9.9 Disassemble the cell and rinse the disc with ethylalcohol 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
27、. Air drying of the electroplateddisc has also been successfully used.9.11 Submit the sample for alpha spectrometry measure-ment.10. Keywords10.1 actinides; alpha spectrometry; electrodepositionASTM International takes no position respecting the validity of any patent rights asserted in connection w
28、ith any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible tec
29、hnical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful considera
30、tion at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr H
31、arbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(w
32、ww.astm.org).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. Pharmaceutical Convention, Inc. (USPC), Rockville,MD.C 1284 00 (2005)2
