1、Designation: C1343 11Standard Test Method forDetermination of Low Concentrations of Uranium in Oilsand Organic Liquids by X-ray Fluorescence1This standard is issued under the fixed designation C1343; the number immediately following the designation indicates the year oforiginal adoption or, in the c
2、ase of revision, the year of last revision. 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 test method covers the steps necessary for thepreparation and analysis by X-ray fluo
3、rescence (XRF) of oilsand organic solutions containing uranium. Two different prepa-ration techniques are described.1.2 The procedure is valid for those solutions containing 20to 2000 g uranium per mLas presented to the spectrometer forthe solution technique and 200 to 50 000 g uranium per g forthe
4、pellet technique.1.3 This test method requires the use of an appropriateinternal standard. Care must be taken to ascertain that samplesanalyzed by this test method do not contain the internalstandard or that this contamination, whenever present, has beencorrected for mathematically. Such corrections
5、 are not ad-dressed in this procedure. Care must be taken that the internalstandard and sample medium are compatible; that is, samplesmust be miscible with tri-n-butyl phosphate (TBP) and mustnot remove the internal standard from solution.Alternatively, ascatter line may be used as the internal stan
6、dard.21.4 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.5 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 establi
7、sh appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. Specific precau-tionary statements are given in Section 9 and Note 2.2. Referenced Documents2.1 ASTM Standards:3C1110 Practice for Sample Preparation for X-Ray EmissionSpectrometric A
8、nalysis of Uranium in Ores Using theGlass Fusion or Pressed Powder MethodC1254 Test Method for Determination of Uranium in Min-eral Acids by X-Ray FluorescenceD1193 Specification for Reagent WaterE135 Terminology Relating to Analytical Chemistry forMetals, Ores, and Related Materials2.2 NIST Documen
9、t:ANSI/HPS N43.22001 Radiation Safety for X-ray Diffrac-tion and X-ray Fluorescence Analysis Equipment43. Terminology3.1 DefinitionsSee definitions in Terminology E135.4. Summary of Test Method4.1 Solution standards containing 20 g uranium per mL to2000 g uranium per mL or pellet standards containin
10、g 200 to50 000 g uranium per g and an internal standard are placed ina liquid sample holder of an X-ray spectrometer and exposed toan X-ray beam capable of exciting the uranium L-a emissionline and the appropriate internal standard line. The intensitiesgenerated are measured by an appropriate detect
11、or. The inten-sity ratio values obtained from these data are used to calibratethe X-ray analyzer. Samples are prepared having a similarmatrix to fit the calibration range and measured using the sameanalytical parameters.NOTE 1Yttrium, strontium, and bromine K-a and thorium L-a lineshave been used su
12、ccessfully as internal standard lines. Explanation of theinternal standard method of analysis is outside the scope of this testmethod and is found in several sources.5,65. Significance and Use5.1 This test method is applicable to organic solutionscontaining 20 to 2000 g uranium per mL of solution pr
13、esented1This test method is under the jurisdiction ofASTM Committee C26 on NuclearFuel Cycle and is the direct responsibility of Subcommittee C26.05 on Methods ofTest.Current edition approved Feb. 1, 2011. Published February 2011. Originallyapproved in 1996. Last previous edition approved in 2007 as
14、 C134396(2007). DOI:10.1520/C1343-11.2Andermann, G., and Kemp, J. W., “Scattered X-rays as Internal Standards inX-ray Spectroscopy,” Analytical Chemistry, Vol 20, No. 8, 1958.3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For
15、 Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.4Available from U.S. Department of Commerce, National Institute of Standardsand Technology, Gaithersburg, MD 20899.5Bertin, E. P., Introduction to X-ray Spectrometric Analysis, Plenum Pr
16、ess, NewYork and London, 1978.6Tertian, R., and Claisse, F., Principles of Quantitative X-ray FluorescenceAnalysis, Heyden such cups decrease the likelihood of contamination of thesamples.7.2.2 Polyester, polyethylene, and polypropylene films havebeen used successfully as the film window for such cu
17、ps. Testsshould be performed to determine the serviceability of any filmchosen before the insertion of samples into the instrument.7.3 Solution Dispenser (Optional)If used, the solutiondispenser for the internal standard solution should be capableof dispensing the internal standard reproducibly to a
18、 level of0.5 % relative standard deviation of the volume dispensed.7.4 Fusion Cruciblesgraphite or platinum are acceptable;platinum is recommended.8. Reagents and Materials8.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reag
19、ents conform to the specifications of the Committee onAnalytical Reagents of the American Chemical Society wheresuch specifications are available.7Other grades may be used,provided it is first ascertained that the reagent is of sufficientlyhigh purity to permit its use without lessening the accuracy
20、 ofthe determination.8.2 Purity of WaterUnless otherwise indicated, referencesto water shall be understood to mean reagent water in con-formance with Specification D1193.8.3 Nitric Acid, HNO3,concentrated (70 %).8.4 1,3,5-Tribromobenzene, technical grade (or substitutefor internal standard).8.5 Tri-
21、n-Butyl Phosphate (TBP), technical grade.8.6 Uranium Oxide,U3O8, NBL CRM 129,8or equivalent.8.7 Lithium Tetraborate,Li2B4O7or LiTB, technical grade,fused and ground (or other fusion flux material).8.8 Yttrium Oxide,Y2O3, spectrographically pure (or suit-able internal standard substitute).9. Technica
22、l Precautions9.1 X-ray fluorescence equipment analyzes by the interac-tion of ionizing radiation with the sample. Applicable safetyregulations and standard operating procedures must be re-viewed prior to the use of such equipment. All current XRFspectrometers are equipped with safety interlock to pr
23、eventaccidental penetration of the X-ray beam by the user. Do notoverride these interlocks (see ANSI/HPS N43.22001).9.2 Instrument performance may be influenced by environ-mental factors such as heat, vibration, humidity, dust, strayelectronic noise, and line voltage stability. These factors andperf
24、ormance characteristics should be reviewed prior to the useof this test method.10. Preparation of Apparatus10.1 Chamber EnvironmentThe standards and samplesused in this test method are corrosive liquids. Some fumes willbe emitted from the sample cups. These fumes may bedetrimental to the spectromete
25、r chamber. It is desirable to flushthis chamber with an inert gas (usually helium) before andduring analysis. Some X-ray spectrometers control the changeof sample chamber environment (air, vacuum, and helium)automatically through the software; in others, it must be donemanually. Follow the instrumen
26、t manufacturers recommenda-tions to achieve the inert gas environment.NOTE 2Caution: Allow sufficient stabilization time before analysis.Care must be taken to ensure that a vacuum environment is not chosenwith liquid samples. Standards and samples must be counted in sameenvironment.10.2 X-ray Power
27、SupplyIf the power to the X-ray tube isnot controlled by the instrument software, set the propercombination of voltage and current for the instrument in use.These settings must be ascertained by the user for his instru-ment and choice of X-ray tube. Rhodium, gold, tungsten, andmolybdenum target X-ra
28、y tubes have been used successfullyfor this analysis. Allow sufficient stabilization time prior toanalysis.11. Calibration and Standardization11.1 Solution Technique11.1.1 Internal Standard Solution:11.1.1.1 Weigh 65.64 g of 1,3,5-tribromobenzene to thenearest 0.1 mg. Transfer the material to a 400-
29、mL beaker; add200 mL of TBP.11.1.1.2 Dissolve the material in TBP; heat on a hot plate, ifnecessary.11.1.1.3 Transfer the dissolved material to a 1000-mLvolumetric flask, and dilute to volume with TBP. (Storage ofthe solution in an opaque container with a screw cap isrecommended.)7Reagent Chemicals,
30、 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 Form
31、ulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.8Available from U.S. Department of Energy, New Brunswick Laboratory, D350,9800 South Cass Avenue, Argonne, IL 60439, Attn: Reference Material Sales.C1343 11211.1.2 “Master” Standards:NOTE 3Because of the difficulty of accurately weighin
32、g the smallamounts of uranium oxide necessary for low-concentration standards,calibration standards are made by dilution from “master” standards. Thetotal volume of the standard prepared may be adjusted to meet the usersanalytical throughput if the weights are adjusted appropriately.11.1.2.1 Prepare
33、 the standards at each desired concentrationlevel by weighing the quantities of uranium oxide given inTable 1 into 400-mL beakers.11.1.2.2 Dissolve the oxide in 50 mL of water and 10 mL ofconcentrated nitric acid. Evaporate the solution to near drynessor to a syrupy solution.11.1.2.3 Add enough TBP
34、to bring the uranium back intosolution. (Keep the volume below 200 mL.)11.1.2.4 Transfer the solution to a 500-mL volumetric flaskusing TBP. When cool, add 1 mL of concentrated nitric acidwhile diluting to volume with TBP; cap and mix thoroughly.11.1.3 “Secondary Master” Standards:11.1.3.1 Prepare a
35、 500 g/mL standard by pipetting 25 mLof the 5000 g/mL“master” standard into a 250-mLvolumetricflask. Dilute to volume with TBP, and mix thoroughly.11.1.3.2 Prepare a 100 g/mL standard by pipetting 25 mLof the 1000 g/mL“master” standard into a 250-mLvolumetricflask. Dilute to volume with TBP, and mix
36、 thoroughly.11.1.4 Calibration Standards:11.1.4.1 Prepare the calibration standards by pipetting intolabeled 50-mL volumetric flasks the amounts of each “master”standard given in Table 2.11.1.4.2 Add 2 mL of the internal standard to each flask.Dilute to volume with TBP, and mix thoroughly.NOTE 4The
37、internal standard solution may be added using anautomatic dispenser or dispensing pipette. However, care must be taken toensure that no adjustment to the dispenser is made between use forstandards and use for samples.11.2 Pellet Technique11.2.1 Internal Standard Solution (25.0 g/L):11.2.1.1 Prepare
38、the internal standard solution as describedin the Calibration heatingrates and cooling rates may vary and cause cracking or poor crystallizationof melt. Remelting in same crucible does not invalidate the analysis.11.3 Instrument Calibration:NOTE 6The frequency of calibration, use of blanks, spikes a
39、ndduplicates, labeling, and length of storage of solutions shall be inaccordance with the users quality assurance/quality control plan andrequirements.11.3.1 Follow the manufacturers instructions for the instru-ment in use to obtain intensity data for the uranium L-a and theinternal standard line fo
40、r each standard.11.3.2 Care must be exercised that the analytical conditionsdetermined appropriate for the instrument in use are docu-mented, or recorded, in sufficient detail that these may bereproduced in subsequent runs and when analyzing thesamples.11.3.3 Calculate the uranium/internal standard
41、ratios fromthe data obtained in 11.3.1. Calculate a calibration curve usingthese ratios. The curve should be at least a second orderpolynomial (quadratic) or should have a term to correct foruranium self-absorption. Both have been found acceptable.Currently available instrument software would contai
42、n one orthe other, or perhaps both. (A complete discussion of themathematical derivation of the following equations is outsidethe scope of this test method. Explanations of correctionmodels and interelement effects are found in severalsources.5,6) The quadratic equation will have the formY 5 CX21 BX
43、 1 A (1)where:Y = concentration of uranium,X = uranium/internal standard intensity ratio, andA,B,C = coefficients of quadratic equation.11.3.4 For self-absorption, the equation will have the formY 5 MX 1 B!1 1aX/100! (2)TABLE 1 “Master” Standards for Uranium in Organic LiquidsUranium Oxide, gAConcen
44、tration, g U/mL2.9490 50000.5898 1000AThe weight of uranium oxide is based on the value of NBL CRM 129. Weightswill need to be adjusted for the purity of the uranium reference material used.Follow instructions on the certificate accompanying the material for drying andpurity correction, where applic
45、able.TABLE 2 Calibration Standards for Uranium in Organic Liquids“Master” Standard Used,g U/mL“Master” StandardPipetted, mLCalibration StandardConcentration, g U/mL5000 20 20005000 15 15005000 10 10001000 25 500500 25 250500 10 100100 25 50100 10 20C1343 113where:Y = concentration of uranium,X = ura
46、nium/internal standard intensity ratio,M = slope of straight line,B = intercept of straight line, anda = self-absorption coefficient.NOTE 7Units used for Y in Eq 1 and Eq 2 may be changed, asappropriate, for the software in use.12. ProcedureNOTE 8Some estimate of the approximate g U/L will be necess
47、ary todetermine the appropriate dilution. This may be obtained by gammacounting of the incoming sample, prior knowledge of the origin of thesample, or some other scheme devised by the user. Such schemes areoutside the scope of this test method.12.1 Sample Preparation:12.1.1 Solution Technique12.1.1.
48、1 Shake the sample and pipet an appropriate amountinto a tared 50-mL volumetric flask.NOTE 9Some estimate of the approximate g U/L will be necessary todetermine the appropriate dilution. This may be obtained by gammacounting of the incoming sample, prior knowledge of the origin of thesample, or some
49、 other scheme devised by the user. Such schemes areoutside the scope of this test method.12.1.1.2 Obtain the gross weight of the sample and flask.(This may be omitted if an answer on a weight basis is notdesired.)12.1.1.3 Add 2 mL of the internal standard solution; diluteto volume with TBP and mix thoroughly.12.1.2 Pellet Technique12.1.2.1 Weigh 15.00 6 0.03 g LiTB into a labeled cruciblefor each test sample desired.12.1.2.2 Shake the sample to homogenize contents. Forextremely thick or viscous samples, stirring with a glass rodmay be the best opti
