1、Designation: C 1416 04Standard Test Method forUranium Analysis Waste Water by X-ray Fluorescence1This standard is issued under the fixed designation C 1416; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision.
2、 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 test method applies for the determination of traceuranium content in waste water. It covers concentrations of Ubetween 0.05 mg
3、/L and 2 mg/L.1.2 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 establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2
4、. Summary of Test Method2.1 Uranyl cations are collected on ion exchange cellulosephosphate papers by circulating the water to be analysedthrough the paper with a peristaltic pump. After drying, theuranium is determined using X-ray fluorescence.3. Significance and Use3.1 Uranium production facilitie
5、s must control trace ura-nium content in their waste waters.3.2 Colorimetric and fluorimetric methods have been devel-oped but require a tedious separation of interfering elements.Trace uranium can also be determined by ICP-MS but not allwater matrices are adapted (for example, waters with high salt
6、content). Direct X-ray fluorescence can be done on the liquidbut with a detection limit of ;5 mg/L3.3 X-ray fluorescence after collection of uranium offers theadvantages to reach low detection limits (0.05 mg/L) and toavoid handling a liquid in the spectrometer.4. Interferences4.1 Uranium is collect
7、ed on the paper by the precipitation ofa uranyl phosphate complex at pH = 2.5. Other cations (forexample, Pb, Bi, Sn, Zr, As,.) having a low phosphatesolubility at low pH are also collected and will interfere only atlarge concentration (the maximum capacity of the paper is 8.5eq/cm2). As an example,
8、 for a solution containing 1 mg/L ofeach Pb, Bi, Sn, Zr, and As, and 0.3 mg/L of uranium, a bias of5 % was detected on the uranium content. See also 9.2.4.2 Other elements such as Fe, Cu, Ni, Al, Cr ., which havea higher phosphate solubility at low pH were found to have noeffect even at concentratio
9、n of 10 mg/L.4.3 The excess of anions forming strong complexes with theuranyl cation can also bias the uranium determination. As anexample, for a solution containing 100 mg/L of F (added asNaF) and 0.3 mg/L of uranium, a bias of 30 % was found onthe uranium determination. On the contrary, anions for
10、mingweak uranyl complexes (such as SO42-,Cl.) were seen tohave no effect even at concentration of several g/L.5. Apparatus5.1 Wavelength dispersive X-ray fluorescence spectrom-eter equipped with a LiF (200) crystal, a molybdenum, tung-sten or rhodium target tube and a scintillation detector.NOTE 1En
11、ergy dispersive instruments may be applicable.5.2 Peristaltic pump capable of achieving a flow rate of 50mL/min.5.3 A filtration apparatus which comprises a filter holder, a250 mL flask located on top of the filter, and a pipe on bottomof the filter connected to the peristaltic pump. The sample to b
12、eanalyzed is poured in the flask, flows through the phosphatefilter and the liquid collected on bottom is brought back to theflask through the peristaltic pump.5.4 Pipet0.2 mL, 1 mL, 5 mL, 10 mL, 20 mL.25.5 pH - meter.5.6 100 mL volumetric flasks.6. Reagents and Materials6.1 Purity of MaterialsReage
13、nt grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents conform to the specification of the Committee onAnalytical Reagents of the American Chemical Society wheresuch specifications are available.3Other grades may be used1This test method is under th
14、e jurisdiction of ASTM Committee C26 on NuclearFuel Cycle and is the direct responsibility of Subcommittee C26.05 on Methods ofTest.Current edition approved June 1, 2004. Published July 2004. Originally approvedin 1999. Last previous edition approved in 1999 as C 141699.2Dilution detailed in 6.5 and
15、 6.7 may also be done by weight. In that case, pipetsare not necessary.3Reagent Chemicals, 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 LaboratoryChe
16、micals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmaceutical Convention, Inc. (USPC), Rockville,MD.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.provided it is first ascertain
17、ed that the reagent is of sufficientlyhigh purity to permit its use without lessening the accuracy ofthe determination.6.2 Purity of WaterConventional distilled water is foundacceptable for this analysis.6.3 Phosphate paper filters.46.4 Concentrated hydrochloric acid, 12.1 M (sp gr 1.187).6.5 Dilute
18、d hydrochloric acid,5M. Add 41 mL of concen-trated hydrochloric acid (sp gr 1.187) to 50 mL H2Oina100mL flask. Dilute to 100 mL with water.6.6 Ammonium chloride solution,2M. Add 10.7 g ofammonium chloride salt to a 100 mL flask. Dilute to 100 mLwith water.6.7 Diluted nitric acid,6M. Add 37 mL of con
19、centratednitric acid (sp gr 1.42) to 50 mL H2O in a 100 mL flask. Diluteto 100 mL with water.6.8 Uranium standard solution, 10 g/L. This solution can beprepared by weighing 11.344 g of certified UO2(for example,OU 1 from CETAMA5with certified uranium content 88.12 60.09 %), or equivalent, and adding
20、 10 mL diluted nitric acid(6.7). After dissolution, dilute to 1 L with distilled water.6.8.1 Uranium standard solution, 10 mg/L, obtained bydilution of solution 6.8.7. Calibration and Standardization7.1 Calibration an be done either in pure water as describedhere or, if an interference is suspected,
21、 in the matrix to beanalysed using spikes. In seven 100 mL volumetric flasks, addrespectively 0, 1, 2, 5, 10, 15, and 20 mL of solution 6.8.1.Dilute to 100 mL with distilled water. The uranium contrationis respectively 0, 0.1, 0.2, 0.5, 1.0, 1.5 and 2.0 mg/L.7.2 For each of the seven solutions (7.1)
22、, proceed asfollows:7.2.1 Adjust the pH of the solution to 2.5 6 0.2 withconcentrated HCl (6.4). The solution volume will then beslightly above 100 mL but will be refered as such forsimplification purposes.7.2.2 Just before the analysis, the phosphate paper must beconverted to the ammonium form: ins
23、ert a P 81 filter in thefilter holder and start the peristaltic pump with a flow rate of 50mL/min. Position the drain line so that the conditioningsolution is not returned to the 250 mL flask. Add 50 mL of DIwater to the 250 mL flask. When this has been pulled throughthe filter, add 100 mL of the di
24、lute HCl (6.5). When completeadd 100 mL of the ammonium chloride solution (6.6). The filteris then ready for collecting uranyl ions and should not dry inbetween.7.2.3 Position the drain line so that sample solution isreturned to the 250 mL flask. Pour the 100 mL solution (7.2.1)in the 250 mL flask.
25、Let it flow for 1.5 h.7.2.4 Recover the filter and let it dry at 50 C for 1 h.7.3 Place the seven filters in the spectrometer holder, andanalyze each by X rays at the uranium La peak, according tomanufacturers recommendations to achieve the users perfor-mance and quality assurance criteria.7.4 Calib
26、rate the spectrometer with the seven standards.When plotting the X rays fluorescence intensity versus theconcentration, a linear curve should be obtained.8. Procedure8.1 Measure out 100 mL of sample and proceed with theanalysis as in 7.2 and 7.3.NOTE 2If the solution contains solids (precipitate, or
27、ganic materials)a preliminary filtration should be done after step 7.2.1 but before step7.2.3. A verification that all uranium has been dissolved after adjusting thepH at 2.5 is recommended.NOTE 3If the solution contains a lot of salts, or if 100 mL are notavailable, a dilution might be necessary pr
28、ior to step 7.2.1. A correctionfactor is then taken in account.8.2 Obtain directly the uranium concentration from thecalibration curve obtained in 7.4.9. Precision and Bias9.1 PrecisionFor a sample containing 0.30 mg/L of ura-nium, 15 analyses have been performed to assess the short-term variability
29、. The estimated relative standard deviation wasfound 2 % relative. The long term variability has been calcu-lated over a fourmonth period (40 analyses), without recali-bration, for a solution containing 0.1 mg/L uranium. Theanalyses were performed by two operators in one facility. Theestimated relat
30、ive standard deviation was found 15 % relative.9.2 Bias:9.2.1 Uranium Recovery Rate on the Phosphate PaperThe recovery rate was calculated by comparing a directcalibration of the X ray spectrometer and the analysis asdescribed in Section 7. Direct calibration of the spectrometerwas performed by depo
31、siting uranium on thin films andanalyzing as in 7.3 and 7.4. On the other hand, a waste watersample was spiked with various uranium concentrations andanalyzed according to 7.1-7.4. Table 1 shows the obtainedresults using the direct calibration. The recovery rate calculatedfrom the four last spikes w
32、as found to be above 90 %.9.2.2 InterferencesBias can be checked when comparingcalibration in pure water and calibration directly in the matrix.See Section 4 for examples of potential interferences.10. Keywords10.1 uranium; waste water; x-ray fluorescence4A P81 Whatman filter has been found satisfac
33、tory.5CEA/CETAMA, BP 171 30 207 Bagnols sur Ceze. France.C1416042ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any su
34、ch patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision 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 invit
35、ed either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments 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
36、 fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted 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
37、 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).TABLE 1Uranium added inwaste waterMeasured fluorescenceintensity (kCp/s)Concentration measuredusing direct calibrationBaseline is subtracted0 mg/L 0.359 0.27 mg/L0.1 mg/L 0.444 0.35 mg/L0.2 mg/L 0.567 0.46 mg/L0.5 mg/L 0.805 0.69 mg/L0.8 mg/L 1.144 0.98 mg/L1.0 mg/L 1.379 1.19 mg/LC1416043
