1、Designation: D4922 09 (Reapproved 2016)1Standard Test Method forDetermination of Radioactive Iron in Water1This standard is issued under the fixed designation D4922; 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.1NOTEEditorial corrections were made to 5.1 in January 2016.1. Scope1.1 This test method covers the determination of55Fe in thepresence
3、 of59Fe by liquid scintillation counting. The a-prioriminimum detectable concentration for this test method is 7.4Bq/L.21.2 This test method was developed principally for thequantitative determination of55Fe. However, after proper cali-bration of the liquid scintillation counter with reference stan-
4、dards of each nuclide,59Fe may also be quantified.1.3 This test method was used successfully with Type IIIreagent water conforming to Specification D1193.Itistheresponsibility of the user to ensure the validity of this testmethod for waters of untested matrices.1.4 This standard does not purport to
5、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 of regulatory limitations prior to use. For a specifichazard statement, see Section 9.2. Ref
6、erenced Documents2.1 ASTM Standards:3D1068 Test Methods for Iron in WaterD1129 Terminology Relating to WaterD1193 Specification for Reagent WaterD2777 Practice for Determination of Precision and Bias ofApplicable Test Methods of Committee D19 on WaterD3370 Practices for Sampling Water from Closed Co
7、nduitsD5847 Practice for Writing Quality Control Specificationsfor Standard Test Methods for Water AnalysisD7282 Practice for Set-up, Calibration, and Quality Controlof Instruments Used for Radioactivity Measurements3. Terminology3.1 DefinitionsFor definitions of terms used in this testmethod, refer
8、 to Terminology D1129. For terms not defined inthis test method or in Terminology D1129, refer to otherpublished glossaries.44. Summary of Test Method4.1 This test method describes the effective separation ofiron from the interfering cations of manganese, cobalt,zirconium, niobium, and cesium by ani
9、on exchange using acidwashes of various molarities. Subsequent elution of the iron isfollowed by phosphate precipitation to remove any residualzinc. The iron phosphate precipitate is dissolved in phosphoricacid and water and mixed with liquid scintillation cocktail. Thechemical yield is determined b
10、y the recovery of iron carrierusing atomic absorption spectrophotometry. Alternatively, anyprocedure described in Test Methods D1068 may be used, butthis will need to be validated by the user prior to reportingsample results.5. Significance and Use5.1 Fe-55 is formed in reactor coolant systems of nu
11、clearreactors by activation of stable iron. The55Fe is not completelyremoved by waste processing systems and some is released tothe environment by means of normal waste liquid discharges.Power plants are required to monitor these discharges for55Feas well as other radionuclides.5.2 This technique ef
12、fectively removes other activation andfission products such as isotopes of iodine, zinc, manganese,cobalt, and cesium by the addition of hold-back carriers and ananion exchange technique. The fission products (zirconium-95and niobium-95) are selectively eluted with hydrochloric-hydrofluoric acid was
13、hes. The iron is finally separated fromZn+2by precipitation of FePO4at a pH of 3.0.1This test method is under the jurisdiction of ASTM Committee D19 on Waterand is the direct responsibility of Subcommittee D19.04 on Methods of Radiochemi-cal Analysis.Current edition approved Jan. 1, 2016. Published
14、January 2016. Originallyapproved in 1989. Last previous edition approved in 2009 as D4922 09. DOI:10.1520/D4922-09R16E01.2Currie, L., “Limits for Qualitative Detection and Quantitative Determination,”Analytical Chemistry, Vol. 40, 1968, pp. 586593.3For referenced ASTM standards, visit the ASTM websi
15、te, 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.4“American National Standard Glossary of Terms,” Nuclear Science andTechnology (ANSI N1.1), American National Sta
16、ndards Institute, 1430 Broadway,New York, NY 10018.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States16. Interferences6.1 Samples of reactor origin will also contain59Fe afterother radioactive contaminants have been removed by anionexcha
17、nge (see Fig. 1).59Fe is also an activation product whichdecays by - emission and will be a source of interference inthe quantitative determination of55Fe. The large difference inthe energies of their characteristic decay emissions makes itpossible to determine appropriate factors to correct for the
18、59Fespectral cross-talk in the55Fe region.6.2 Quenching, which may be caused by a number offactors, results in a reduction in light output from the sample.The subsequent decrease in the spectral pulse height will causevariations in the counting efficiency with varying degrees ofquench. For this reas
19、on, it is necessary to monitor both thechanges in the55Fe efficiency and the59Fe cross-talk in the55Fe region as a function of quench. This technique recom-mends the use of the automatic external standard ratio suppliedby most liquid scintillation counters to monitor the amount ofquench in a sample.
20、6.3 The final heating of the sample solution will drive off allexcess hydrochloric acid, ammonia, and water. These sub-stances are, therefore, effectively removed as possible quench-ing agents.6.4 Scintillation stock or sample solutions which have beenexposed to light must be dark adapted to avoid e
21、rratic resultsdue to light activation of the scintillator.NOTE 1It is the responsibility of the user to determine the requireddark adaptation period for the specific cocktail used.6.5 The stable iron content in a sample will interfere in thedetermination of the chemical recovery. Since the amount of
22、stable iron in a sample will depend on its sources, a correctionfor the iron in the sample must be made.7. Apparatus7.1 Liquid Scintillation Counter, with an automatic externalstandard and multiple energy region of interest (ROI) capabili-ties.7.2 Glass Scintillation Vials, 20-mLvials exhibiting sui
23、tableoptical reproducibility so as not to cause erratic results amongsamples.7.3 Atomic Absorption Spectrophotometer.7.4 Variable Speed Peristaltic Pump, with controller. Pumpspeed should be between 5 and 8 mL/min.7.5 Centrifuge, using 100 mL centrifuge tubes.7.6 Volumetric Flasks.7.7 Anion Exchange
24、 Columns:7.7.1 ColumnsCommercially available plastic dryingtubes and ends (40 mL volume, 1.5 cm diameter, 15 cm long).7.7.2 TubingPump inlet tubing, approximately 45.7 cm(18 in.) in length, and pump outlet tubing, approximately 76.2cm (30 in.) in length.7.7.3 Polyethylene Porous Disc35-m pore size a
25、nd 3.2mm thick.8. Reagents and Materials8.1 Purity of ReagentsReagent grade chemicals shall beused for all tests. Unless otherwise indicated, it is intended thatall reagents shall conform to the specifications of the Commit-tee on Analytical Reagents of the American Chemical Society,where such speci
26、fications are available.5Other grades may beused, provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the determination.8.2 Purity of WaterUnless otherwise indicated, referencesto water shall be understood to mean reagent
27、 water conformingto Specification D1193, Type III.8.3 ResinAGl-X8, AG1-X10, 200400 mesh; 25 mL pre-viously equilibrated with 125 mL concentrated hydrochloricacid.8.4 Scintillation CocktailCommercially prepared Insta-Gel scintillator or equivalent non-ionic detergent scintillator ofthe octyl-phenyl p
28、olyglycol ether type.6NOTE 2To obtain a clear aqueous final sample, the sample volumemust be kept below 1.8 mL with the addition of 15 mL Insta-Gel. It is theresponsibility of the user to determine the optimum sample volume tococktail volume to obtain a clear homogeneous solution for any otherliquid
29、 scintillation cocktail used.5Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For Suggestions on the testing of reagents notlisted by the American Chemical Society, see Annual Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and
30、 the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.6The sole source of supply of the apparatus known to the committee at this timeis Insta-Gel scintillator, available from PerkinElmer Life and Analytical Sciences,940 Winter Street, Waltham
31、, MA 02451. If you are aware of alternative suppliers,please provide this information to ASTM International Headquarters. Your com-ments will receive careful consideration at a meeting of the responsible technicalcommittee,1which you may attend.FIG. 1 Percent of Total Radionuclide Activity Removed P
32、er AcidWashD4922 09 (2016)128.5 Ammonium Hydroxide (NH4OH)Concentrated (ap-proximately 15M) (sp gr 0.90).8.6 Ammonium Phosphate (0.5 M)Dissolve 66 g of am-monium monohydrogen phosphate (NH4)2HPO4 in water anddilute to 1000 mL with water in a volumetric flask.8.7 Cesium Carrier Solution (1 mg/1 mL)Ce
33、sium ascesium chloride (CsCl) in dilute hydrochloric acid.78.8 Cobalt Carrier Solution (1 mg/1 mL)Cobalt as cobaltchloride (CoCl2) in dilute hydrochloric acid.78.9 Hydrochloric Acid (sp gr 1.187)Concentrated HCl.8.10 Hydrochloric Acid 10 MDilute 833 mL of concen-trated hydrochloric acid in 100 mL wa
34、ter and dilute to 1000mL with water in a volumetric flask.8.11 Hydrochloric Acid 6 MDilute 500 mL of concen-trated hydrochloric acid in 400 mL of water, dilute to 1000 mLwith water in a volumetric flask.8.12 Hydrochloric Acid 4 MDilute 333 mL of concen-trated hydrochloric acid in 600 mL of water, di
35、lute to 1000 mLwith water in a volumetric flask.8.13 Hydrochloric Acid 0.5 MDilute 42 mL of concen-trated hydrochloric acid in 900 mL of water, dilute to 1000 mLwith water in a volumetric flask.8.14 Hydrochloric Acid 0.01 MDilute 20 mL of 0.5 MHCl in 900 mL of water, dilute to 1000 mL with water in
36、avolumetric flask.8.15 Hydrochloric (6 M)-Hydrofluoric Acid (0.5 M)Dilute 500 mL of concentrated hydrochloric acid (HCl) (sp gr1.187) and 20 mL of 49 % concentrated hydrofluoric acid (HF)in 400 mL of water, dilute to 1000 mL with water in a plasticor TFE-fluorocarbon volumetric flask.8.16 Iron Carri
37、er Solution (Fe+3as ferric chloride)7Dissolve 5.00 g of metallic iron in 300 mL of 6 M HCl, filter,dilute to 1 L, and calibrate using an atomic absorptionspectrophotometer (Test Methods D1068).8.17 Manganese Carrier Solution (1 mg/1 mL)Mn+2indilute nitric acid (HNO3).78.18 Niobium Carrier Solution (
38、1 mg/1 mL)Nb+5in 5 %hydrofluoric acid (1 + 9 M).78.19 Nitric Acid (sp gr 1.42)Concentrated (HNO3).8.20 Phosphoric Acid (sp gr 1.834)Concentrated(H3PO4).8.21 Sodium Hydroxide (6 M)Dissolve 24 g sodium hy-droxide (NaOH) in 90 mL water, allow to cool, and dilute to100 mL with water and store in plastic
39、 bottles; a commerciallyprepared solution may also be used.8.22 Zinc Carrier Solution (1 mg/mL)Zn+2in dilutehydrochloric acid.78.23 Zirconium Carrier Solution (1 mg/mL)Zr+4in dilutehydrochloric acid.78.2455Fe Standard SolutionTraceable to a national stan-dards laboratory such as National Institute o
40、f Standards andTechnology (NIST) or UK National Physical Laboratory(NPL).8.2559Fe Standard SolutionTraceable to a national stan-dards laboratory such as NIST or NPL.9. Hazards9.1 HF is extremely hazardous and should be used in awell-ventilated hood. Wear rubber gloves, safety glasses orgoggles, and
41、a laboratory coat.Avoid breathing any HF fumes.Clean all spills and wash thoroughly after using HF. Also, donot add HF to any glassware for it is a significant hazard andcan affect analytical accuracy.10. Sampling10.1 Collect samples in accordance with procedures pre-sented in Practices D3370, as ap
42、plicable.10.2 If the sample is not acidified at the time of collection,20 mLof concentrated HCl or HNO3should be added per 1000mL of sample. After acidification of the sample, the sampleshould be allowed to sit overnight prior to analysis.11. Calibration11.1 The reference standard for both iron isot
43、opes willcontain 5 mg iron carrier. Add 6 drops of concentratedphosphoric acid to the carrier solution and heat on a hot plateuntil it clears. This will drive off any excess hydrochloric acidand water (to less than 0.5 mL but do not allow to bake dry).Add 1 mL of water and swirl in the glass vial. T
44、his final carriersolution should be colorless. Cool the vial to room temperature.Spike with the appropriate isotope and add 15 mL of scintil-lation cocktail. Cap and shake until the mixture is clear; thisstep ensures that the proper sample volume to scintillationcocktail volume ratio is obtained for
45、 a clear, homogeneoussolution. The volume of the reference standard should be suchthat its addition to the sample does not cause additionalquench.11.2 Prepare a series of quenched55Fe standards and aseries of quenched59Fe standards using various weights of ironcarrier or concentration or volumes, or
46、 both, of acid. Use theleast quenched standards in each set to optimize the liquidscintillation counter (LSC) discriminator settings and amplifiergain. Ensure that the55Fe spectrum does not spill over intothe59Fe ROI. If your instrument does not allow for multiplenuclides to be optimized follow Prac
47、tice D7282 for instrumentoptimization.11.3 Count each set of standards with the LSC automaticexternal standard ratio selected on to obtain approximately 1 %counting statistics (approximately 10 000 counts) in the ROI.11.4 Prepare a curve of the55Fe efficiency versus theexternal standard ratio.11.5 P
48、repare a crosstalk (XT) curve of the ratio of59Fecounts in the55Fe ROI to the59Fe counts in the59Fe ROIversus the external standard ratio.7Commercially available atomic absorption reference standards in 1 mg=1mLconcentrations may be used as carriers.D4922 09 (2016)1311.6 Additional guidance on the s
49、et-up, calibration andcalibration verification of the instrument can be found inPractice D7282.12. Procedure12.1 Measure an acidified and filtered aliquant of the sample(approximately 0.05 L) into a 100 mL centrifuge tube.12.1.1 A background subtraction sample shall be processedin accordance with 12.2 through 12.16 with each set ofsamples.12.2 Add 5 mg iron carrier and mix well.12.3 Add NaOH (6 M), mix, and heat to precipitate ironhydroxide.12.4 Centrifuge and decant the supernatant solution towaste.12.5 Wash the precipitate with 50 mL of
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