1、Designation: C1343 11C1343 16Standard 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,
2、in the case 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 the preparation and analysis by X
3、-ray fluorescence (XRF) of oils and organicsolutions containing uranium. Two different preparation techniques are described.1.2 The procedure is valid for those solutions containing 20 to 2000 g uranium per mL as presented to the spectrometer forthe solution technique and 200 to 50 000 g uranium per
4、 g for the pellet technique.1.3 This test method requires the use of an appropriate internal standard. Care must be taken to ascertain that samples analyzedby this test method do not contain the internal standard or that this contamination, whenever present, has been corrected formathematically. Suc
5、h corrections are not addressed in this procedure. Care must be taken that the internal standard and samplemedium are compatible; that is, samples must be miscible with tri- n-butyl phosphate (TBP) and must not remove the internalstandard from solution. Alternatively, a scatter line may be used as t
6、he internal standard.21.4 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this
7、standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use. Specific precautionary statements are given in Section 9 and Note 2.2. Referenced Documents2.1 ASTM Standards:3C1110 Test Method for Determining Elements in Waste Stre
8、ams by Inductively Coupled Plasma-Atomic Emission Spectroscopy(Withdrawn 2014)4C1254 Test Method for Determination of Uranium in Mineral Acids by X-Ray FluorescenceD1193 Specification for Reagent WaterE135 Terminology Relating to Analytical Chemistry for Metals, Ores, and Related Materials2.2 NIST D
9、ocument:ANSI/HPS N43.22001 Radiation Safety for X-ray Diffraction and X-ray Fluorescence Analysis Equipment53. Terminology3.1 DefinitionsSee definitions in Terminology E135.4. Summary of Test Method4.1 Solution standards containing 20 g uranium per mL to 2000 g uranium per mL or pellet standards con
10、taining 200 to50 000 g uranium per g and an internal standard are placed in a liquid sample holder of an X-ray spectrometer and exposed toan X-ray beam capable of exciting the uranium L- emission line and the appropriate internal standard line. The intensities1 This test method is under the jurisdic
11、tion of ASTM Committee C26 on Nuclear Fuel Cycle and is the direct responsibility of Subcommittee C26.05 on Methods of Test.Current edition approved Feb. 1, 2011June 1, 2016. Published February 2011July 2016. Originally approved in 1996. Last previous edition approved in 20072011 asC134396(2007).C13
12、43 11. DOI: 10.1520/C1343-11.10.1520/C1343-16.2 Andermann, G., and Kemp, J. W., “Scattered X-rays as Internal Standards in X-ray Spectroscopy,” Analytical Chemistry, Vol 20, No. 8, 1958.3 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceast
13、m.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.4 The last approved version of this historical standard is referenced on www.astm.org.5 Available from U.S. Department of Commerce, National Institute of Standards and Technol
14、ogy, Gaithersburg, MD 20899.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends
15、that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1generated are measur
16、ed by an appropriate detector. The intensity ratio values obtained from these data are used to calibrate theX-ray analyzer. Samples are prepared having a similar matrix to fit the calibration range and measured using the same analyticalparameters.NOTE 1Yttrium, strontium, and bromine K- and thorium
17、L- lines have been used successfully as internal standard lines. Explanation of the internalstandard method of analysis is outside the scope of this test method and is found in several sources.6,75. Significance and Use5.1 This test method is applicable to organic solutions containing 20 to 2000 g u
18、ranium per mL of solution presented to thespectrometer for the solution techniques or 200 to 50 000 g uranium per g using the fused pellet technique.5.2 Either wavelength-dispersive or energy-dispersive XRF systems may be used, provided that the software accompanying thesystem is able to accommodate
19、 the use of internal standards.6. Interferences6.1 This test method requires the use of an internal standard. Care must be taken that the samples analyzed by this test methoddo not contain the internal standard or chemicals that would remove the internal standard from solution. The samples must also
20、be miscible with TBP if using the solution technique.7. Apparatus7.1 X-ray SpectrometerSee manufacturers literature for the selection of the X-ray spectrometer. The procedure is valid foreither energy-dispersive or wavelength-dispersive systems.7.2 Sample Cups:7.2.1 Prepare liquid sample cups for th
21、e X-ray spectrometer as described by the manufacturer. Vented, disposable sample cupswith snap-on caps are satisfactory for most such analyses; such cups decrease the likelihood of contamination of the samples.7.2.2 Polyester, polyethylene, and polypropylene films have been used successfully as the
22、film window for such cups. Testsshould be performed to determine the serviceability of any film chosen before the insertion of samples into the instrument.7.3 Solution Dispenser (Optional)If used, the solution dispenser for the internal standard solution should be capable ofdispensing the internal s
23、tandard reproducibly to a level of 0.5 % 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 be used in all tests. Unless otherwise indicated,
24、 it is intended that allreagents conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society where suchspecifications are available.8 Other grades may be used, provided it is first ascertained that the reagent is of sufficiently high purityto permit its use
25、 without lessening the accuracy of the determination.8.2 Purity of WaterUnless otherwise indicated, references to water shall be understood to mean reagent water in conformancewith Specification D1193.8.3 Nitric Acid, HNO3,concentrated , concentrated (70 %).8.4 1,3,5-Tribromobenzene, technical grade
26、 (or substitute for internal standard).8.5 Tri-n-Butyl Phosphate (TBP), technical grade.8.6 Uranium Oxide, U3O8, NBL CRM 129,129-A,9 or equivalent.8.7 Lithium Tetraborate, Li2B4O7 or LiTB, technical grade, fused and ground (or other fusion flux material).8.8 Yttrium Oxide, Y2O3, spectrographically p
27、ure (or suitable internal standard substitute).9. Technical Precautions9.1 X-ray fluorescence equipment analyzes by the interaction of ionizing radiation with the sample. Applicable safetyregulations and standard operating procedures must be reviewed prior to the use of such equipment.All current XR
28、F spectrometersare equipped with safety interlock to prevent accidental penetration of the X-ray beam by the user. Do not override these interlocks(see ANSI/HPS N43.22001).6 Bertin, E. P., Introduction to X-ray Spectrometric Analysis, Plenum Press, New York and London, 1978.7 Tertian, R., and Claiss
29、e, F., Principles of Quantitative X-ray Fluorescence Analysis, Heyden in others, it must be done manually. Follow theinstrument manufacturers recommendations to achieve the inert gas environment.NOTE 2Caution:Allow sufficient stabilization time before analysis. Care must be taken to ensure that a va
30、cuum environment is not chosen with liquidsamples. Standards and samples must be counted in same environment.10.2 X-ray Power SupplyIf the power to the X-ray tube is not controlled by the instrument software, set the propercombination of voltage and current for the instrument in use. These settings
31、must be ascertained by the user for his instrument andchoice of X-ray tube. Rhodium, gold, tungsten, and molybdenum target X-ray tubes have been used successfully for this analysis.Allow sufficient stabilization time prior to analysis.11. Calibration and Standardization11.1 Solution Technique11.1.1
32、Internal Standard Solution:11.1.1.1 Weigh 65.64 g of 1,3,5-tribromobenzene to the nearest 0.1 mg. Transfer the material to a 400-mL beaker; add 200 mLof TBP.11.1.1.2 Dissolve the material in TBP; heat on a hot plate, if necessary.11.1.1.3 Transfer the dissolved material to a 1000-mL volumetric flask
33、, and dilute to volume with TBP. (Storage of the solutionin an opaque container with a screw cap is recommended.)11.1.2 “Master” Standards:NOTE 3Because of the difficulty of accurately weighing the small amounts of uranium oxide necessary for low-concentration standards, calibrationstandards are mad
34、e by dilution from “master” standards. The total volume of the standard prepared may be adjusted to meet the users analyticalthroughput if the weights are adjusted appropriately.11.1.2.1 Prepare the standards at each desired concentration level by weighing the quantities of uranium oxide given in Ta
35、ble1 into 400-mL beakers.11.1.2.2 Dissolve the oxide in 50 mL of water and 10 mL of concentrated nitric acid. Evaporate the solution to near drynessor to a syrupy solution.11.1.2.3 Add enough TBP to bring the uranium back into solution. (Keep the volume below 200 mL.)11.1.2.4 Transfer the solution t
36、o a 500-mL volumetric flask using TBP. When cool, add 1 mL of concentrated nitric acid whilediluting to volume with TBP; cap and mix thoroughly.11.1.3 “Secondary Master” Standards:11.1.3.1 Prepare a 500 g/mLstandard by pipetting 25 mLof the 5000 g/mL“master” standard into a 250-mLvolumetric flask.Di
37、lute to volume with TBP, and mix thoroughly.11.1.3.2 Prepare a 100 g/mLstandard by pipetting 25 mLof the 1000 g/mL“master” standard into a 250-mLvolumetric flask.Dilute to volume with TBP, and mix thoroughly.11.1.4 Calibration Standards:11.1.4.1 Prepare the calibration standards by pipetting into la
38、beled 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 internal standard solution may be added using an automatic dispenser or dispensing pipette. However, c
39、are must be taken to ensure thatno adjustment to the dispenser is made between use for standards and use for samples.TABLE 1 “Master” Standards for Uranium in Organic LiquidsUranium Oxide, gA Concentration, g U/mL2.9490 50000.5898 1000AThe weight of uranium oxide is based on the value of NBLCRM 129.
40、 Weights willneed to be adjusted for the purity of the uranium reference material used. Followinstructions on the certificate accompanying the material for drying and puritycorrection, where applicable.C1343 16311.2 Pellet Technique11.2.1 Internal Standard Solution (25.0 g/L):11.2.1.1 Prepare the in
41、ternal standard solution as described in the Calibration heating rates and cooling rates may vary and cause cracking or poor crystallization ofmelt. Remelting in same crucible does not invalidate the analysis.11.3 Instrument Calibration:NOTE 6The frequency of calibration, use of blanks, spikes and d
42、uplicates, labeling, and length of storage of solutions shall be in accordance withthe users quality assurance/quality control plan and requirements.11.3.1 Follow the manufacturers instructions for the instrument in use to obtain intensity data for the uranium L- and theinternal standard line for ea
43、ch standard.11.3.2 Care must be exercised that the analytical conditions determined appropriate for the instrument in use are documented,or recorded, in sufficient detail that these may be reproduced in subsequent runs and when analyzing the samples.11.3.3 Calculate the uranium/internal standard rat
44、ios from the data obtained in 11.3.1. Calculate a calibration curve using theseratios. The curve should be at least a second order polynomial (quadratic) or should have a term to correct for uraniumself-absorption. Both have been found acceptable. Currently available instrument software would contai
45、n one or the other, orTABLE 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 20TABLE 3 Standards for Pellet Techn
46、iqueStandard Value(ug U/g)Uranium Oxide(g)AStandard Value(g U/g)Uranium Oxide(g)A250 0.00029500 0.000591000 0.001181750 0.002062500 0.002955000 0.005907500 0.0088510 000 0.0118015 000 0.0176920 000 0.0235925 000 0.0294930 000 0.0353935 000 0.0412940 000 0.0471950 000 0.05898A Based on value of NBL C
47、RM-129A.CRM-129. Follow instructions on certificatewith material for drying or isotopic correction, or both.C1343 164perhaps both. (A complete discussion of the mathematical derivation of the following equations is outside the scope of this testmethod. Explanations of correction models and interelem
48、ent effects are found in several sources.6,7) The quadratic equation willhave the formY 5CX2 1BX1A (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 5MX1B!11X
49、/100! (2)where:Y = concentration of uranium,X = uranium/internal standard intensity ratio,M = slope of straight line,B = intercept of straight line, and = self-absorption coefficient.NOTE 7Units used for Y in Eq 1 and Eq 2 may be changed, as appropriate, for the software in use.12. ProcedureNOTE 8Some estimate of the approximate g U/L will be necessary to determine the appropriate dilution. This may be obtained by gamma countingof the incoming sample, prior knowledge of the origin of the sample, or some other scheme devised by the us
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