1、Designation: C 1163 03Standard Practice forMounting Actinides for Alpha Spectrometry UsingNeodymium Fluoride1This standard is issued under the fixed designation C 1163; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of la
2、st 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 frac-tions of actinides for alpha spectrometry as an alternate toelec
3、trodeposition. It is applicable to any of the actinides thatcan be dissolved in dilute hydrochloric acid. Examples ofapplicable samples would be the final elution from an ionexchange separation or the final strip from a solvent extractionseparation.21.2 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. For a specifichazard statement, see Section 8.2. Referenced Docu
5、ments2.1 ASTM Standards:D 1193 Specification for Reagent Water3D 3084 Practice for Alpha-Particle Spectrometry of Water43. Summary of Test Method3.1 Guidance is provided for the sample mounting ofseparated actinides using coprecipitation with neodymiumfluoride. The purified samples are prepared and
6、mounted on amembrane filter to produce a deposit that yields alpha spectraequal to electrodeposited samples. Samples can be preparedmore rapidly than by electrodeposition and have comparableresolution.4. Significance and Use4.1 The determination of actinides by alpha spectrometry isan essential func
7、tion of many environmental programs. Alphaspectrometry allows the identification and quantification ofmost alpha-emitting actinides. Although numerous separationmethods are used, the final sample preparation technique hashistorically been by electrodeposition. However, electrodepo-sition may have so
8、me drawbacks, such as time required,incompatibility with prior chemistry, thick deposits, and lowrecoveries. These problems can be minimized using the neody-mium fluoride method.4.2 The sample mounting technique described in this prac-tice is rapid, adds an additional purification step, since onlyth
9、ose elements that form insoluble fluorides are mounted, andthe sample and filter media can be dissolved and remounted ifproblems occur. The recoveries are better and resolutionapproaches normal electrodeposited samples. Recoveries aresufficiently high that for survey work, if quantitative recoveries
10、are not necessary, tracers can be omitted. Drawbacks to thistechnique include use of very hazardous hydrofluoric acid andthe possibility of a non-reproducible and ill-defined countinggeometry from filters that are not flat. Also, although the totalturn around time for coprecipitation may be less tha
11、n forelectrodeposition, coprecipitation required more time and at-tention from the analyst.5. Interferences5.1 Calculation of a result from a sample that gives poorresolution should not be attempted since it probably implies anerror in performing the separation or mounting procedure.6. Apparatus6.1
12、Alpha SpectrometerA system should be assembledthat is capable of 60 to 70 keV resolution on an actual sampleprepared by this practice, have a counting efficiency of greaterthan 20 %, and a background of less than 0.005 cpm over eachdesignated energy region. Resolution is defined as the full-width at
13、 half-maximum (FWHM) in keV, or the distancebetween those points on either side of the alpha energy peakwhere the count is equal to one-half the maximum count.Additional information can be found in Practice D 3084.6.2 Filter25-mm 0.1 m pore, polypropylene membranefilter or equivalent.56.3 Vacuum Fun
14、nelPolysulfone twist-lock with stainlesssteel screen for filter mounting.51This practice is under the jurisdiction of ASTM Committee C26 on the NuclearFuel Cycle and is the direct responsibility of Subcommittee C26.05 on Methods ofTest.Current edition approved July 10, 2003. Published August 2003. O
15、riginallyapproved in 1992 as C 1163 92. Last previous edition approved in 1998 asC 1163 98.2Hindman, F. D., “Actinide Separations for Alpha Spectrometry Using Neody-mium Fluoride Coprecipitation,” Analytical Chemistry, 58, 1986, pp. 12361241.3Annual Book of ASTM Standards, Vol 11.01.4Annual Book of
16、ASTM Standards, Vol 11.02.5Available from Pall Life Sciences, Ann Arbor, MI, catalog number M5PU025.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6.4 Ultrasonic Bath.7. Reagents7.1 Purity of ReagentsReagent-grade chemicals must beu
17、sed in all procedures. Unless otherwise indicated, all reagentsshould conform to the specifications of the Committee onAnalytical Reagents of the American Chemical Society, if suchspecifications are available.6Other grades may be used, if it isascertained that the reagent is of sufficiently high pur
18、ity topermit its use without reducing the accuracy of the determina-tion. All reagents should be stored in polypropylene bottles.7.2 Purity of WaterUnless otherwise indicated, watermeans reagent water as defined in Specification D 1193, TypeIII.7.3 Reagent BlanksReagent blanks should be analyzed tod
19、etermine their contribution to the sample result.7.4 Neodymium Chloride Stock Solution (10 mg Nd/mL)Heat 25 mL of 12N hydrochloric acid and 1.17 g of neody-mium oxide on a hotplate until the neodymium oxide is insolution. Cool the solution and dilute to 100 mL with water.7.5 Neodymium Chloride Carri
20、er Solution (0.5 mg Nd/mL)Dilute 5 mL of the 10 mg Nd/mL neodymium chloridestock solution to 100 mL with water.7.6 Carbon SuspensionFume ten 47-mm cellulose filters7for about 10 min in 10 mL of 18M sulfuric acid. Cool thesuspension and dilute to 500 mL with water. The carbonsuspension is used as a v
21、isual aid in identifying the presence ofthe precipitate.7.7 Substrate SolutionDilute 1 mL of the 10-mg Nd/mLneodymium chloride and 20 mL of 12M hydrochloric acid to400 mL with water. Add, with swirling, 10 mL of 29Mhydrofluoric acid and 8 mL of the carbon suspension. Dilutethe suspension to 500 mL w
22、ith water. Each day before use,place the substrate suspension in a sonic bath for 15 min.7.8 Hydrochloric Acid (sp gr 1.19)Concentrated hydro-chloric acid (12M HCl).7.9 3N Hydrochloric AcidAdd 250 mL concentrated hy-drochloric acid to water and dilute to 1 L with water.7.10 Sulfuric Acid (sp gr 1.84
23、)Concentrated sulfuric acid(18M H2SO4).7.11 Hydrofluoric Acid (48 %)Concentrated hydrofluoricacid (29M HF). WarningSevere burns can result fromexposure of skin to concentrated hydrofluoric acid.7.12 Neodymium Oxide (Nd2O3).7.13 80 % Ethanol.7.14 20 % Titanium TrichlorideAvailable as a 20 % solu-tion
24、 of titanium trichloride from commercial suppliers.7.15 Sodium Sulfate SolutionDissolve 52 g of anhydroussodium sulfate in 500 mL of 18M sulfuric acid.7.16 Safranine-0 Solution, 0.1 %Dissolve 0.1 g ofsafranine-0 in 100 mL of water.8. Hazards8.1 WarningAdequate laboratory facilities, such as fumehood
25、s and controlled ventilation, along with safe techniquesmust be used in this procedure. Extreme care should beexercised in using hydrofluoric and other hot, concentratedacids. Use of rubber gloves is recommended.9. Sample Preparation9.1 Add 2 mL of sodium sulfate solution to the actinidefraction and
26、 evaporate to complete dryness in a glass beaker.Cool to room temperature and add 10 mL of 3 N HCl. Coverthe beaker with a watch glass, bring to a boil, and keep at aboiling temperature for 5 min.9.2 Transfer the solution to a capped 50-mL plastic centri-fuge tube using about 2 mL of 3N HCl as a rin
27、se. For uranium,follow procedure described in 9.6-9.8.9.3 Add 100 L of the 0.5 mg/mL Nd carrier solution to thetube. Gently shake the capped tube to mix the solution.9.4 Add 5 mL of 48 % HF to the solution in the tube andmix well by gently swirling the tube. Let stand at least 5 min.9.5 Proceed with
28、 mounting procedure (Section 10).9.6 Add 1 drop of 0.1 % safranine-0 and 2 drops titaniumtrichloride to the uranium solution. Uranium reduction isindicated by a change from a purple or blue to an almostcolorless solution. If this color change does not occur orpersist, add another drop or two of tita
29、nium trichloride.9.7 Add 100 L of the 0.5 mg/mL Nd carrier solution to theuranium solution. Gently swirl the tube to mix the solution.9.8 Add 5 mL of 48 % HF to the uranium solution and mixwell by gently swirling the tube. Let stand at least 5 min. Areappearance of color at this step may indicate in
30、completeuranium reduction and require the addition of more titaniumtrichloride and additional neodymium chloride carrier solution.9.9 Proceed with mounting procedure (Section 10).10. Mounting Procedure10.1 Mount a 25-mm membrane filter on a stainless steelsupport in a polysulfone twist-lock funnel.1
31、0.2 With vacuum applied, draw about 2 mL of 80 %ethanol through the filter.10.3 As the filter becomes dry, add the following solutions,in order, to the center of the filter:10.3.1 Five mL of the substrate solution which has beenfreshly treated for 15 min in a sonic bath,10.3.2 The vigorously stirred
32、 sample from a capped tube,10.3.3 Five mL of 3N HCI is used to rinse the samplecontainer,10.3.4 Five mL of water is used to rinse the samplecontainer, and10.3.5 Two mL of 80 % ethanol is used to rinse the filter.10.4 Dry the filter for 5 min under an infra-red heat lamp ata distance of 12 to 16 in.
33、Excess heating in drying will distortthe filter.10.5 Apply a 2.54 cm wide double-coated cellophane typetape8to one side of a clean, 2.54 cm diameter, stainless steel6“Reagent Chemicals, American Chemical Society Specifications,” Am. Chemi-cal Soc., Washington, DC. For suggestions on the testing of r
34、eagents not listed bythe American Chemical Society, see “Reagent Chemicals and Standards,” by JosephRosin, D. Van Nostrand Co., Inc., New York, NY, and the “United StatesPharmacopeia.”7Ga-6 Metricel or equivalent has been found suitable for this purpose.8Scotch 665 has been found suitable for this p
35、urpose.C1163032disk. Trim the tape flush with the edge of the disk using a bladeor knife. Center the dried filter on the taped side of the disk.Attach the filter to the tape by gently pressing the edge of thefilter in several places with the tip of a forceps or tweezers.10.6 Submit the sample for al
36、pha spectrometry.11. Precision and Bias11.1 This practice addresses an intermediate step in anoverall separation and measurement scheme and does notproduce a measurement. Hence, a statement of precision andbias is not meaningful.ASTM International takes no position respecting the validity of any pat
37、ent 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 rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision
38、 at any time by the responsible technical 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 comm
39、ents will receive careful consideration 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 copyrighte
40、d by ASTM International, 100 Barr Harbor 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(www.astm.org).C1163033
