ASTM D3605-17 Standard Test Method for Trace Metals in Gas Turbine Fuels by Atomic Absorption and Flame Emission Spectroscopy.pdf

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1、Designation: D3605 17Standard Test Method forTrace Metals in Gas Turbine Fuels by Atomic Absorptionand Flame Emission Spectroscopy1This standard is issued under the fixed designation D3605; the number immediately following the designation indicates the year oforiginal adoption or, in the case of rev

2、ision, 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. Scope*1.1 This test method covers the determination of sodium,lead, calcium, and vanadium in Specification D

3、2880 GradeNos. 0-GT through 4-GT fuels at 0.5 mg kg level for each ofthe elements. This test method is intended for the determina-tion of oil-soluble metals and not waterborne contaminants inoil-water mixtures.1.1.1 Test Method D6728 is suggested as an alternative testmethod for the determination of

4、 these elements in SpecificationD2880.1.2 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the u

5、ser of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision o

6、n Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D2880 Specification for Gas Turbine Fuel OilsD4057 Practice for Manual Sampling of Petr

7、oleum andPetroleum ProductsD4177 Practice for Automatic Sampling of Petroleum andPetroleum ProductsD6728 Test Method for Determination of Contaminants inGas Turbine and Diesel Engine Fuel by Rotating DiscElectrode Atomic Emission Spectrometry3. Summary of Test Method3.1 The samples are prepared to c

8、onform with the require-ments of the method of standard additions, which is selected toobviate problems encountered with the direct analysis oftypical gas turbine fuels that exhibit significant variations inphysical properties. Different, but known, amounts of analyteare added to two portions of sam

9、ple. These, together with theunaltered sample, are burned in the flame of an atomicabsorption instrument that measures light absorption by theatomized metals. The analysis of the sample portions withadded analyte provides the calibration information necessary tocalculate the analyte content of the u

10、naltered sample.3.2 Lead is determined by atomic absorption in a premixedair-acetylene flame, and sodium is determined by atomicabsorption or atomic emission in a premixed air-acetyleneflame. Calcium and vanadium are determined by atomicabsorption or atomic emission in a premixed nitrous oxide-acety

11、lene flame.3.3 Most experience with this test method has been in theatomic absorption mode, although flame emission has beenused successfully. Details in the subsequent sections arewritten for the atomic absorption mode. If the flame emissionmode is used, minor details in the subsequent sections mus

12、t bealtered to conform to standard practice for flame emissionspectroscopy. The precision statement applies only to theatomic absorption mode.NOTE 1Some GT fuel users may wish to determine potassium inaddition to other metals included in this method. Potassium can bedetermined in a manner similar to

13、 that for sodium using a potassiumhollow cathode lamp, (unless flame emission mode is used) a wavelengthof 766.4 mm, and an appropriate organo-potassium standard. Precisiondata for potassium have not been determined.4. Significance and Use4.1 Knowledge of the presence of trace metals in gas turbinef

14、uels enables the user to predict performance and, whennecessary, to take appropriate action to prevent corrosion.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products, Liquid Fuels, and Lubricantsand is the direct responsibility ofSubcommittee D02.03 on Elemental Ana

15、lysis.Current edition approved June 1, 2017. Published June 2017. Originallyapproved in 1977. Last previous edition approved in 2016 as D3605 16. DOI:10.1520/D3605-17.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual

16、Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis internation

17、al standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee

18、.15. Apparatus5.1 Atomic Absorption Spectrophotometer, capable of mea-suring radiation over the wavelength range from 280 nm to600 nm. The instrument must be capable of measuring low-level signals (approximately 1 % absorption or 0.004 absor-bance unit per milligram per litre vanadium). The instrume

19、ntshould also be equipped as follows.5.1.1 Burner, with variable nebulizer and auxiliary oxidantsupply to reduce non-atomic absorption from unburned hydro-carbons which cause interferences.5.1.1.1 Burner Head, capable of supporting a nitrous oxide-acetylene flame.5.1.1.2 Burner Head, single- or mult

20、iple-slot, capable ofsupporting an air-acetylene flame.5.1.2 Electronic Detection System, capable of reading to thenearest 0.1 % absorption or 0.0004 absorbance.5.1.2.1 The text describes the measurement of absorptionsignals that is, either percent absorption or absorbance. Forinstruments reading in

21、 percent absorption, absorption signalsof 0.1 % absorption must be measurable. For instrumentsreading in absorbance, signals of 0.0004 absorbance must bemeasurable.5.1.3 Hollow Cathode Lamp Power Supply, regulated tominimize drift.5.1.4 Monochromator, capable of resolving the 318.34 nm 318.40 nm van

22、adium doublet from the 318.54 nm vanadiumline.5.1.5 Hollow Cathode Lamps, one each for calcium,sodium, lead, and vanadium.NOTE 2Electrodeless-discharge lamps can be an acceptablealternative, but the precision of this method was determined with hollowcathode lamps.5.1.6 When the instrument has flame-

23、emission capability,the emission technique can be used for the analyses of sodium,calcium, and vanadium.5.2 Volumetric Flasks, 25 mL.5.3 Glass Vials, 40 mL, screw-cap type, polyethylene-linedcaps.5.4 Syringe, 100 L, Hamilton type or equivalent.6. Reagents6.1 Purity of ReagentsReagent grade chemicals

24、 shall beused in tests. Unless otherwise indicated, it is intended that allreagents conform to the specifications of the Committee onAnalytical Reagents of the American Chemical Society wheresuch specifications are available.3Other grades may be used,provided it is ascertained that the reagent is of

25、 sufficiently highpurity to permit its use without lessening the accuracy of thedetermination.6.2 1,2,3,4-tetrahydronaphthalene,4practical grade,analyte-sterile.NOTE 3Analyte-sterile 1,2,3,4-tetrahydronaphthalene can be preparedby extracting a portion of tetralin with an equal amount of hydrochloric

26、acid in a covered screw-cap vial. Heat the vial on a steam bath for1handshake the vial for 1 h. If the acid extracted 1,2,3,4-tetrahydronaphthaleneand unextracted 1,2,3,4-tetrahydronaphthalene give indistinguishable ab-sorption signals for each of the analytes under optimal experimentalconditions, t

27、he unextracted 1,2,3,4-tetrahydronaphthalene can be usedthroughout this method.6.3 Organometallic StandardsOil-soluble salts of sodium,lead, calcium, and vanadium of known concentration.56.4 Mixed StandardPrepare a mixed standard containing250 mg L each of sodium, lead, calcium, and vanadium bydisso

28、lving the appropriate amounts of organometallic standardsin 1,2,3,4-tetrahydronaphthalene and making the required di-lutions. Prepare fresh daily, as needed.6.5 Quality Control Samples, preferably are portions of oneor more liquid petroleum materials that are stable and repre-sentative of the sample

29、s of interest. These QC samples can beused to check the validity of the testing process as described inSection 8.7. Sampling7.1 Samples shall be taken in accordance with the instruc-tions in Practice D4057 or D4177.8. Procedure8.1 Fill two clean 25 mL volumetric flasks to the line withsample. With t

30、he microlitre syringe add 50 L of mixedstandard to one flask and 100 L to the other. Touch the needleof the syringe to the inner wall of the flask to ensurequantitative transfer of the standard. Invert and mix thecontents. (The two flasks are now spiked with 0.5 mg L and1.0 mg L of sodium, lead, cal

31、cium, and vanadium).Alternatively, weigh 25.0 g of sample into each of two cleandisposable glass vials and add the standard in the same manner.(The two vials are now spiked with 0.5 mg kg and 1.0 mg kgof sodium, lead, calcium, and vanadium.)8.2 Prepare a third spiked sample by adding approximately1

32、mL of the mixed standard to approximately 25 mL of sample.This solution serves only to aid in establishing satisfactoryoperating conditions for the atomic absorption instrument.8.3 Establish the atomic absorption instrument operatingconditions, which are recommended by the manufacturer, and3Reagent

33、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 LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand Nat

34、ional Formulary, U.S. Pharmaceutical Convention, Inc. (USPC), Rockville,MD.4Tetralin (1,2,3,4-tetrahydronaphthalene), manufactured by E. I. duPont deNemours and Co., has been found satisfactory. If you are aware of alternativesuppliers, please provide this information to ASTM International Headquart

35、ers.Your comments will receive careful consideration at a meeting of the responsibletechnical committee,1which you may attend.5Conostan standards, available from Conostan Division, Continental Oil Co.,Ponca City, OK 74601, were used in determining the precision quoted in thismethod. Other standards

36、are available from the Office of Standard ReferenceMaterials, Room B314, Chemistry Bldg., National Institute of Standards andTechnology, Washington, DC 20234, and from Angstrom, Inc., P. O. Box 252,Belleville, MI 48111, but the precision statement may or may not apply to resultsobtained with these s

37、tandards.D3605 172consider the following special points. Select the mode, flamegases, and spectral lines from the information presented inTable 1.8.4 Analysis:8.4.1 With the atomic absorption instrument in operation formonitoring lead absorption and with 1,2,3,4-tetrahydronaphthalene nebulizing, zer

38、o the instrument. Aspi-rate into the flame the third spiked sample described in 8.2 andnote the net lead absorption signal. Optimize experimentalconditions by adjusting the burner position (relative to thehollow cathode beam), the flow rates of the fuel and oxidantgases, and the sample aspiration ra

39、te until the net leadabsorption signal maximizes. Re-zero the instrument with1,2,3,4-tetrahydronaphthalene nebulizing, and consecutivelyintroduce into the flame the unaltered sample and the twospiked samples, with 1,2,3,4-tetrahydronaphthalene nebulizingbetween each sample. Record the absorption sig

40、nal of eachsample and of each blank between samples.8.4.1.1 At optimal experimental conditions, the analyteconcentration that accounts for 1 % absorption should beapproximately 1 mg L or 1 mg kg. The percent absorption toconcentration ratio must be near unity in order to achieve thelower limits of d

41、etection that are required. This note does notapply to flame emission measurements.8.4.2 With the atomic absorption instrument in operation formonitoring vanadium absorption and with 1,2,3,4-tetrahydronaphthalene nebulizing, zero the instrument. Intro-duce into the flame the third spiked sample desc

42、ribed in 8.2.Record the net vanadium absorption signal. Optimize theexperimental conditions as in 8.4.1. Re-zero the instrumentwith 1,2,3,4-tetrahydronaphthalene nebulizing and consecu-tively introduce into the flame the unaltered sample and the twospiked samples. Record the absorption signal of eac

43、h sampleand of each 1,2,3,4-tetrahydronaphthalene blank betweensamples.8.4.3 With the atomic absorption instrument in operation formonitoring sodium absorption, zero the instrument with 1,2,3,4-tetrahydronaphthalene nebulizing, and consecutively intro-duce into the flame the unaltered sample and the

44、 two spikedsamples. Record the absorption signal of each sample and ofeach 1,2,3,4-tetrahydronaphthalene blank between samples.NOTE 4For determining sodium and calcium, the maximization ofabsorption or emission signals is not critical.8.4.4 With the atomic absorption instrument in operation formonit

45、oring calcium absorption, zero the instrument with 1,2,3,4-tetrahydronaphthalene nebulizing, and consecutively intro-duce into the flame the unaltered sample and the two spikedsamples. Record the absorption signal of each sample and ofeach 1,2,3,4-tetrahydronaphthalene blank between samples.9. Calcu

46、lation9.1 For each absorption signal, calculate the net absorptionsignal as follows:a 5 A 2 b11b2!/2# (1)where:a = net absorption signal,A = observed absorption signal,b1= blank signal before the sample, andb2= blank signal after the sample.NOTE 5Blank corrections are usually small. If a large drift

47、 in blanksignals is observed during a series of measurements, some experimentalparameter is out of control. The cause of the variation should be corrected,and the measurements repeated.9.2 For each element in turn, calculate sensitivities asfollows:S0.55 2 a12 a2! (2)S1.05 a32 a2! (3)S 5 S0.51S1.0!/

48、2 (4)where:S0.5= sensitivity for the 0.5 mg L or 0.5 mg kg spikedsample,S1.0= sensitivity for the 1.0 mg L or 1.0 mg kg spikedsample,S = average sensitivity,a1= net absorption signal for the 0.5 mg L or 0.5 mg kgspiked sample,a2= net absorption signal for the unaltered sample, anda3= net absorption

49、signal for the 1.0 mg L or 1.0 mg kgspiked sample.9.3 Calculate the ratio of sensitivities, R, as follows:R 5 S1.0/S0.5(5)If R falls outside the range of 0.90 R 1.10, the data arenonlinear. Readjust experimental conditions and repeat theanalysis.9.4 Calculate the concentration of each element as follows:mg/L 5 a2/S (6)mg/kg 5 a2/S 3 d! (7)where d = density of the sample in grams ger millilitre.10. Quality Control Checks (QA/QC)10.1 When QA/QC protocols are already established in thetesting facility, these may be used to confirm the reliability o