ASTM D4107-1998(2002)e1 Standard Test Method for Tritium in Drinking Water《饮用水中氚含量的试验方法》.pdf

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1、Designation: D 4107 98 (Reapproved 2002)e1Standard Test Method forTritium in Drinking Water1This standard is issued under the fixed designation D 4107; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A nu

2、mber in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.e1NOTESections 1.4, 10.1.1, 10.1.2, and 12.3.1 were editorially updated in July 2002.1. Scope1.1 This test method covers the determination of tritiu

3、m indrinking water (as T2O or HTO) by liquid scintillation countingof the tritium beta particle activity.1.2 This test method is used successfully with drinkingwater. It is the users responsibility to ensure the validity of thistest method for waters of untested matrices.1.3 The tritium concentratio

4、ns, which can be measured bythis test method utilizing currently available liquid scintillationinstruments, range from less than 0.037 Bq/mL (1 pCi/mL) to555 Bq/mL (15 000 pCi/mL) for a 10-mL sample aliquot.Higher tritium concentrations can be measured by diluting orusing smaller sample aliquots, or

5、 both.1.4 The maximum contaminant level for tritium in drinkingwater as given by the National Interim Primary Drinking WaterRegulations (NIPDWR) is 0.740 Bq/mL (20 pCi/mL). TheNIPDWR lists a required detection limit for tritium in drinkingwater of 0.037 Bq/mL(1 pCi/mL), meaning that drinking watersu

6、pplies, where required, should be monitored for tritium at asensitivity of 0.037 Bq/mL (1 pCi/mL). In Appendix X1,EqX1.3 is given for determining the necessary counting time tomeet the required sensitivity for drinking water monitoring.1.5 This standard does not purport to address all of thesafety c

7、oncerns, 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:D 1129 Terminology Relating to Water2

8、D 1193 Specification for Reagent Water2D 2777 Practice for Determination of Precision and Bias ofApplicable Methods of Committee D19 on Water2D 3370 Practices for Sampling Water from Closed Con-duits2D 3648 Practices for the Measurement of Radioactivity33. Terminology3.1 DefinitionsFor definitions o

9、f terms used in this testmethod, refer to Terminology D 1129. For terms not defined inthis test method or in Terminology D 1129, reference may bemade to other published glossaries.44. Summary of Test Method4.1 In this test method, a 100-mL drinking water samplealiquot is treated with a small amount

10、of sodium hydroxide andpotassium permanganate, distilled, and a specified fraction ofthe distillate is collected for tritium analysis. The alkalinetreatment is to prevent other radionuclides, such as radioiodineand radiocarbon from distilling over with the tritium. Somedrinking water supplies will c

11、ontain trace quantities of organiccompounds, especially surface water sources that contain fishand other life. The permanganate treatment is to oxidize traceorganics in the sample aliquots which could distill over andcause quenching interferences. A middle fraction of the distil-late is collected fo

12、r tritium analysis because the early and latefractions are more apt to contain interfering materials for theliquid scintillation counting process.4.2 As the sample distills, there is a gradient in the tritiumconcentration in the accumulating distillate; therefore, it isimportant to collect the same

13、fraction of the distillate for allsamples and standards for tritium analysis.4.3 The collected distillate fraction is thoroughly mixed anda portion (up to 10 mL) is mixed with liquid scintillatorsolution, and after dark adapting, is counted in the liquidscintillation counting system for tritium beta

14、 particle activity.5. Significance and Use5.1 This test method was developed for measuring tritium inwater to determine if the concentration exceeds the regulatorystatutes of drinking water. This test method also is applicablefor the determination of tritium concentration in water asrequired by tech

15、nical specifications governing the operations of1This 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 March 10, 1998. Published December 1998. Originallypublishe

16、d as D 4107 91. Last previous edition D 4107 98.2Annual Book of ASTM Standards, Vol 11.01.3Annual Book of ASTM Standards, Vol 11.02.4American National Glossary of Terms in Nuclear Science and Technology,available from American National Standards Institute (ANSI), 25 W. 43rd St., 4thFloor, New York,

17、NY 100361Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.nuclear power facilities. With suitable counting technique,sample size, and counting time a detection limit of less than 37Bq/L (1000 pCi/L) is attainable by liquid scintillatio

18、n.6. Interferences6.1 A reduced counting efficiency may result from quench-ing in the sample scintillator mixture. Quenching is caused byimpurities in the sample, which can inhibit the transfer ofenergy, or by colored materials, which may absorb some of theemitted light. Corrections for quenching ca

19、n be made by theuse of internal standards4or by the ratio method.5Theapproach described in this test method, distillation after alka-line permanganate treatment, eliminates quenching substances,as well as radionuclides which might be present in a volatilechemical form such as radioiodine and radioca

20、rbon. A boilingchip must be used with each distillation to avoid bumping,which can amount to a carry over excursion.6.2 Scintillator stock solution or samples exposed to day-light must be dark-adapted. Also, toluene or xylene basescintillators exposed to fluorescent lighting should be dark-adapted f

21、or a minimum of 6 h and dioxane base scintillatorsexposed to fluorescent lighting for 24 h. All fluors should hechecked for excitation under lighting conditions being used,and if possible, they should be exposed only to red light.7. Apparatus7.1 Liquid Scintillation Spectrometer, coincidence-type.7.

22、2 Liquid Scintillation Vials, of low-potassium glass arerecommended. Polyethylene vials may be used when dioxanescintillator solution is used.7.3 Distillation ApparatusFor aqueous distillation,250-mL and 1000-mL round bottom borosilicate flasks, con-necting side arm adapter,6condenser, graduated cyl

23、inder,boiling chips, and heating mantle.8. Reagents and Materials8.1 Purity of ReagentsReagent grade chemicals shall beused in 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

24、Society,where such specifications are available.7Other 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.8.1.1 All chemicals should be of reagent-grade or equiva-lent whenever they a

25、re commercially available.8.2 Purity of WaterUnless otherwise indicated, referencesto water shall be understood to mean reagent water conformingto Specification D 1193, Type III.8.3 Reagents of Distillation Treatment:8.3.1 Sodium Hydroxide Pellets.8.3.2 Potassium Permanganate.8.4 Background Water, w

26、ith tritium activity below theminimum detectable activity (most deep well waters are low intritium content).8.5 Scintillator Solutions:8.5.1 Dioxane Liquid Scintillator SolutionDissolve4gofscintillation-grade PPO (2,5-diphenyloxazole), 0.05 g ofscintillation-grade POPOP 1,4-bis (5-phenyloxazolyl-2-y

27、l)-benzene, and 120 g of naphthalene in 1 L of spectroquality,1,4-dioxane. Store the solution in a dark (amber) bottle. Thissolution can be used with glass or polyethylene vials.8.5.2 Solution G Scintillator SolutionDissolve 18 g ofscintillation-grade PPO (2,5-diphenyloxazole) and 3.6 g ofscintillat

28、ion-grade BIS-MSB p-bis (o-methylstyryl) benzenein 2 L of spectroquality p-xylene. Add 1 L of Triton N-1018detergent to the p-xylene scintillator solution. Dissolve 50 g ofSXS (sodium xylene sulfonate) in 100 mL of water and addthis solution to the p-xylene scintillator-Triton solution. Mixthoroughl

29、y. Store the solution in a dark (amber) bottle. Thissolution should be used with glass vials since the p-xylenesolvent evaporates slowly through the wall of the polyethylenevials.8.5.3 Other commercially available scintillators can beused, such as the environmentally safe di-isopropyl napthalenebase

30、d scintillators. It is the responsibility of the user to verifythe acceptability of a substitute scintillator.9. Sampling9.1 Collect the sample in accordance with Practices D 3370.9.2 Since tritium in drinking water is likely to be in the formof T2O or HTO, there is no need for special handling orpr

31、eservation.10. Calibration10.1 Determination of Recovery and Counting EffciencyFactors:10.1.1 Prepare in a 1-L volumetric flask, a tritium standardsolution containing approximately 17 disintegrations/s(dps)/mL using low level tritium background raw water (un-distilled) and standard tritium activity.

32、 Label this solution asraw water tritium standard solution. Distill approximately 600mL of water obtained from the same raw water source (RWS)as above (without tritium activity added).10.1.1.1 Use this distillate for background tritium determi-nations. Using the distillate and standard tritium activ

33、ity,prepare a tritium standard solution in a 500-mL volumetricflask to contain the same specific activity as the raw watertritium standard solution. Label this solution as distilled watertritium standard solution.10.1.2 Aqueous Alkaline Permanganate DistillationPlacea 100-mL aliquot of the raw water

34、 tritium standard solution ina 250-mL distillation flask.Add 0.5 g of sodium hydroxide, 0.1g of potassium permanganate, and a boiling chip. Proceed withthe distillate according to the procedure described in 11.1,5Bush, E.T., “GeneralApplicability of the Channels Radio Method of MeasuringLiquid Scint

35、illation Counting Efficiencies,” Analytical Chemistry, 35:1024, 1963.6Corning part no. 9060 has been found satisfactory for this purpose.7Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the

36、 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.8Triton products are available from Rohm and Haas Company, IndependenceMall Wes

37、t, Philadelphia, PA 19105.D 4107 98 (2002)e12discard 10 mL, and collect 50 mL of distillate for analysis. Mixthe 50-mL distillate fraction. Repeat the distillation with twomore 100-mL aliquots for triplicate analyses.10.1.3 Prepare for counting three aliquots of the raw watertritium standard solutio

38、n distillate (from 10.1.2), three aliquotsof the distilled water tritium standard solution, and threealiquots of the distilled raw water (for background). Mix 4 mLof water with 16 mL of the dioxane scintillator solution, or 10mL of water with 12 mL of Solution G scintillator solution ina liquid scin

39、tillator vial (glass vials should be used fordetergent-type scintillator solutions). Shake well, dark-adaptthe vials overnight, and count in a liquid scintillation counter.Count each vial long enough to meet the required detection(0.037 Bq/mL) or longer (see Appendix X1 for calculatingrequired count

40、ing time).11. Procedure11.1 Add 0.5 g of sodium hydroxide and 0.1 g of potassiumpermanganate to a 100-mL aliquot of the sample in a 250-mLdistillation flask. Add a boiling chip to the flask. Connect aside-arm adapter and a condenser to the outlet of the flask.Place a graduated cylinder at the outlet

41、 of the condenser. Heatthe sample to boiling to distill, collect the first 10 mL ofdistillate as a separate fraction and discard it.NOTE 1It is important that only the first 10-mL fraction be discardedor the same fraction for samples and standards alike since there is agradient in the tritium concen

42、tration of the distillate. Collect the next 50mL of distillate for tritium analysis. Thoroughly mix the 50-mL distillatefraction.11.2 Thoroughly mix 4 mL of the distillate with 16 mL ofthe dioxane scintillator or 10 mL of distillate with 12 mL ofSolution G scintillator in a liquid scintillation vial

43、. Threealiquots of each sample distillate should be analyzed fortritium.11.3 Prepare background standard tritium-water solutionsfor counting, using the same amount of water and the samescintillator as used in the preparation of samples. Use lowtritium background distilled water for these preparation

44、s (dis-tillate of most deep well water sources is acceptable, but eachsource should be checked for tritium activity before using).11.4 Dark-adapt all samples, backgrounds, and standards.Count the samples, backgrounds, and standards at least longenough to meet the required detection limit (0.037 Bq/m

45、L) forthe sample (see Appendix X1 for calculating counting time forrequired detection limit). The RWS distillate should be countedfor sufficient time to accumulate at least 50 000 net counts.12. Calculation12.1 Counting Effciency, e:e5DWS , cps 2 BDWS, dps(1)where:DWS = distilled water standard, and

46、B = background aliquot count rate, cps.12.2 Recovery Correction Factor, F:F 5RWS distillate, cps 2 Be3RWS, dps before distillation!(2)where:RWS = raw water standard.12.3 Sample Tritium Activity, A:ABq/mL! 5R 2 Be3V 3 F(3)where:R = sample aliquot gross count rate, cps,B = background aliquot count rat

47、e, cps,e = counting efficiency, as determined in Eq 1,V = volume of the sample aliquot, mL, andF = recovery factor, as determined in Eq 2.12.3.1 Error associated with the results of the analysisshould be reported.12.4 The total propagated uncertainty associated with themeasured concentration, A, can

48、 be calculated as follows:sABq/mL! 5 ABq/mL!*SdNND21SdeeD21SdVVD21SdFFD2(4)where:A = tritium concentration in Bq/mL,N = net count rate in cps = RB,tB= counting time for background in s,tR= counting time for sample in s,sN=1s uncertainty of the net count rate in cps =R/tR1 B/tB,sV=1s uncertainty in v

49、olume measurement,se=1s uncertainty in counting efficiency, andsF=1s uncertainty in recovery factor.13. Quality Control13.1 Before this test method is utilized for the analysis ofsamples, a counter quality control or tolerance chart shall beestablished to ensure the counting system is operating withinprescribed limits. The quality control or tolerance chart shall beestablished at the time the counting system is calibrated.13.2 Prepare a quality control or tolerance chart as recom-mended in Practices D 3648. The counting system shall bechecked by analyzing a QC