ASTM D5708-2005 752 Standard Test Methods for Determination of Nickel Vanadium and Iron in Crude Oils and Residual Fuels by Inductively Coupled Plasma (ICP) Atomic Emission Spectro.pdf

1、Designation: D 5708 05An American National StandardStandard Test Methods forDetermination of Nickel, Vanadium, and Iron in Crude Oilsand Residual Fuels by Inductively Coupled Plasma (ICP)Atomic Emission Spectrometry1This standard is issued under the fixed designation D 5708; the number immediately f

2、ollowing the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope*1.1 These test

3、methods cover the determination of nickel,vanadium, and iron in crude oils and residual fuels byinductively coupled plasma (ICP) atomic emission spectrom-etry. Two different test methods are presented.1.2 Test Method A (Sections 7-11 and 18-22)ICP is usedto analyze a sample dissolved in an organic s

4、olvent. This testmethod uses oil-soluble metals for calibration and does notpurport to quantitatively determine or detect insoluble particu-lates.1.3 Test Method B (Sections 12-22)ICP is used to analyzea sample that is decomposed with acid.1.4 The concentration ranges covered by these test methodsar

5、e determined by the sensitivity of the instruments, theamount of sample taken for analysis, and the dilution volume.A specific statement is given in 15.2. Typically, the lowconcentration limits are a few tenths of a mg/kg. Precision dataare provided for the concentration ranges specified in Section2

6、1.1.5 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.6 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 a

7、ppro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 1193 Specification for Reagent WaterD 1548 Test Method for Vanadium in Navy Special FuelOil3D 4057 Practice for Manual Sampling of Petroleum an

8、dPetroleum ProductsD 4177 Practice for Automatic Sampling of Petroleum andPetroleum ProductsD 5185 Test Method for Determination of Additive Ele-ments, Wear Metals, and Contaminants in Used Lubricat-ing Oils and Determination of Selected Elements in BaseOils by Inductively Coupled Plasma Atomic Emis

9、sionSpectrometry (ICP-AES)D 6299 Practice for Applying Statistical Quality AssuranceTechniques to Evaluate Analytical Measurement SystemPerformance3. Summary of Test Method3.1 Test Method AApproximately 10 g of the sample aredissolved in an organic solvent (WarningCombustible. Va-por is harmful.) to

10、 give a specimen solution containing 10 %(m/m) of sample. The solution is nebulized into the plasma,and the intensities of the emitted light at wavelengths charac-teristic of the analytes are measured sequentially or simulta-neously. The intensities are related to concentrations by theappropriate us

11、e of calibration data.3.2 Test Method BOne to 20 g of sample are weighed intoa beaker and decomposed with concentrated sulfuric acid(WarningPoison. Causes severe burns. Harmful or fatal ifswallowed or inhaled.) by heating to dryness. Great care mustbe used in this decomposition because the acid fume

12、s arecorrosive and the mixture is potentially flammable. The re-sidual carbon is burned off by heating at 525C in a mufflefurnace. The inorganic residue is digested with nitric acid(WarningPoison. Causes severe burns. Harmful or fatal ifswallowed or inhaled.), evaporated to incipient dryness, dis-so

13、lved in dilute nitric acid, and made up to volume. Thesolution is nebulized into the plasma of an atomic emissionspectrometer. The intensities of light emitted at characteristic1These test methods are under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct

14、responsibility of SubcommitteeD02.03 on Elemental Analysis.Current edition approved Nov. 1, 2005. Published November 2005. Originallyapproved in 1995. Last previous edition approved in 2002 as D 570802.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Serv

15、ice at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Withdrawn.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohock

16、en, PA 19428-2959, United States.Copyright by ASTM Intl (all rights reserved); Fri Dec 19 02:38:50 EST 2008Downloaded/printed byGuo Dehua (CNIS) pursuant to License Agreement. No further reproductions authorized.wavelengths of the metals are measured sequentially or simul-taneously. These intensitie

17、s are related to concentrations by theappropriate use of calibration data.4. Significance and Use4.1 These test methods cover, in single procedures, thedetermination of Ni, V, and Fe in crude oils and residual oils.These test methods complement Test Method D 1548, whichcovers only the determination

18、of vanadium.4.2 When fuels are combusted, vanadium present in the fuelcan form corrosive compounds. The value of crude oils can bedetermined, in part, by the concentrations of nickel, vanadium,and iron. Nickel and vanadium, present at trace levels inpetroleum fractions, can deactivate catalysts duri

19、ng processing.These test methods provide a means of determining theconcentrations of nickel, vanadium, and iron.5. Purity of Reagents5.1 Reagent grade chemicals shall be used in all tests.Unless otherwise indicated, it is intended that all reagentsconform to the specifications of the Committee on An

20、alyticalReagents of the American Chemical Society where suchspecifications are available.4Other grades may be used, pro-vided it is first ascertained that the reagent is of sufficientlyhigh purity to permit its use without lessening the accuracy ofthe determination.5.2 When determining metals at con

21、centrations less than 1mg/kg, use ultra-pure reagents.5.3 Purity of WaterUnless otherwise indicated, referenceto water shall be understood to mean reagent water conformingto Type II of Specification D 1193.6. Sampling and Sample Handling6.1 The objective of sampling is to obtain a sample fortesting

22、purposes that is representative of the entire quantity.Thus, take samples in accordance with the instructions inPractice D 4057 or D 4177. Do not fill the sample containermore than two-thirds full.6.2 Prior to weighing, stir the sample and manually shakethe sample container. If the sample does not r

23、eadily flow atroom temperature, heat the sample in a drying oven at 80C orat another safe temperature.TEST METHOD AICP WITH AN ORGANIC SOLVENT SPECIMENSOLUTION7. Apparatus7.1 Inductively Coupled Plasma Atomic EmissionSpectrometerEither a sequential or simultaneous spectrom-eter, equipped with a quar

24、tz torch and radio-frequency genera-tor to form and sustain the plasma, is suitable.7.2 NebulizerThe use of a high-solids nebulizer is op-tional but strongly recommended. This type of nebulizerminimizes the probability of clogging. A concentric glassnebulizer can also be used.7.3 Peristaltic PumpThi

25、s pump is required for non-aspirating nebulizers and optional for aspirating nebulizers.The pump must achieve a flow rate in the range of 0.5 to 3mL/min. The pump tubing must be able to withstand at least a6 h exposure to the solvent. Fluoroelastomer copolymer tubingis recommended.57.4 Specimen Solu

26、tion Containers, glass or plastic vials orbottles with screw caps having a capacity of appropriate size.One hundred millilitre glass bottles are satisfactory.8. Reagents8.1 Dilution SolventMixed xylenes, o-xylene, tetralin andmixed paraffin-aromatic solvents are satisfactory. Solvent pu-rity can aff

27、ect analytical accuracy when the sample containslow concentrations (typically, a few mg/kg) of the analytes.8.2 Mineral OilA high-purity oil such as U.S.P. white oil.8.3 Organometallic StandardsPre-prepared multielementconcentrates containing 100 mg/kg concentrations of eachelement are satisfactory.

28、8.4 Quality Control (QC) Samples, preferably are portionsof one or more liquid petroleum materials that are stable andrepresentative of the samples of interest. These QC samplescan be used to check the validity of the testing process asdescribed in Section 19.9. Preparation of Standards and Specimen

29、s9.1 BlankPrepare a blank by diluting mineral oil withdilution solvent. The concentration of mineral oil must be 10 %(m/m). Mix well.9.2 Check StandardUsing organometallic standards, min-eral oil, and dilution solvent, prepare a check standard tocontain analyte concentrations approximately the same

30、asexpected in the specimens. The concentration of oil in thecheck standard must be 10 % (m/m).9.3 Test SpecimenWeigh a portion of well-mixed sampleinto a container and add sufficient solvent to achieve a sampleconcentration of 10 % (m/m). Mix well.9.4 Working StandardPrepare an instrument calibratio

31、nstandard that contains 10 mg/kg each of vanadium, nickel, andiron. Combine the organometallic standard, dilution solventand, if necessary, mineral oil so that the oil content of thecalibration standard is 10 % (m/m).9.5 Quality Control (QC) SamplesWeigh a portion of thewell-mixed QC sample into a c

32、ontainer and add sufficientsolvent to achieve a sample concentration of 10 % (m/m).10. Preparation of Apparatus10.1 Consult the manufacturers instructions for the opera-tion of the ICP instrument. This test method assumes that goodoperating procedures are followed. Design differences betweeninstrume

33、nts make it impractial to specify required parameters.4Reagent 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.,

34、 Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.5Fluoroelastomer copolymer is manufactured as Viton, a trademark owned by E.I. duPont de Nemours.D5708052Copyright by ASTM Intl (all rights reserved); Fri Dec 19 0

35、2:38:50 EST 2008Downloaded/printed byGuo Dehua (CNIS) pursuant to License Agreement. No further reproductions authorized.10.2 Assign the appropriate operating parameters to theinstrument taskfile so that the desired analytes can be deter-mined. Parameters include: (1) element, (2) analytical wave-le

36、ngth, (3) background correction wavelengths (optional), (4)interelement correction factors (refer to 10.3), (5) integrationtime of 1 to 10 s, (6) two to five consecutive repeat integra-tions. Suggested wavelengths are listed in Table 1.10.3 Spectral InterferencesCheck all spectral interfer-ences exp

37、ected for the analytes. If interference corrections arenecessary, follow the manufacturers operating guide to de-velop and apply correction factors.10.3.1 Spectral interferences can usually be avoided byjudicious choice of analytical wavelengths. If spectral interfer-ences cannot be avoided, the nec

38、essary corrections should bemade using the computer software supplied by the instrumentmanufacturer or by using the empirical method described inTest Method D 5185.10.4 Consult the instrument manufacturers instructions foroperating the instrument with organic solvents.10.5 During instrument warm-up,

39、 nebulize the blank solu-tion. Inspect the torch for carbon build-up. When carbonbuild-up occurs, replace the torch and adjust the operatingconditions to correct the problem.10.5.1 Carbon build-up within the torch can be caused byimproperly adjusted argon flow rates, improper solution flowrates, and

40、 positioning the torch injector tube too close to theload coil. Carbon deposits can invalidate a calibration andextinguish the plasma.11. Calibration and Analysis11.1 Using the blank and working standard, perform atwo-point calibration at the beginning of the analysis of eachbatch of specimens. Addi

41、tional working standards can be used,if desired.11.2 Use the check standard to determine if the calibrationfor each analyte is accurate. When the result obtained on thecheck standard is not within 65 % of the expected concentra-tion for each analyte, take corrective action and repeat thecalibration.

42、11.3 Analyze the specimens in the same manner as thecalibration standards (that is, same integration time, plasmaconditions, and so forth). Calculate concentrations by multi-plying the concentration determined for the test specimensolution by the dilution factor. Calculation of concentrationscan be

43、performed manually or by computer when such afeature is available.11.4 When the measured intensities for the test specimensolution exceed the corresponding intensities for the workingstandard, either ensure that the calibration curve is linear to theconcentration of the element in the test specimen

44、solution ordilute the test specimen solution with the blank solution andreanalyze.11.5 Analyze the check standard after every fifth specimen.If any result is not within 5 % of the expected concentration,take corrective action, repeat the calibration, and reanalyze thespecimen solutions back to the p

45、revious acceptable checkstandard analysis.11.6 The use of spectral background correction is highlyrecommended, particularly when the test specimen solutionscontain low concentrations of the analytes (typically less than1 mg/kg). When concentrations are low, background changes,which can result from v

46、ariability in the compositions of testspecimen solutions, can affect the accuracy of the analysis.Background correction minimizes errors due to variable back-ground intensities.TEST METHOD BICP AFTER ACID DECOMPOSITION OF SAMPLE12. Apparatus12.1 Refer to 7.1-7.4.12.2 Sample Decomposition Apparatus (

47、optional)Thisapparatus is shown in Fig. 1. It consists of a high-silica orborosilicate 400-mL beaker for the specimen, an air bath (Fig.2) that rests on a hot plate, and a 250-watt infrared lampsupported 1 in. above the air bath. A variable transformercontrols the voltage applied to the lamp.12.3 Gl

48、assware, high-silica or borosilicate 400-mL beakers,volumetric flasks of various capacities, and pipettes of variouscapacities. When determining concentrations below 1 mg/kg,all glassware must be thoroughly cleaned and rinsed withwater.12.4 Electric Muffle Furnace, capable of maintaining 525 625C an

49、d sufficiently large to accommodate 400-mL beakers.The capability of an oxygen bleed is advantageous andoptional.TABLE 1 Elements Determined and Suggested WavelengthsNOTEThese wavelengths are suggestions and do not represent allpossible choices.AElement Wavelength, nmIron 259.94, 238.20Nickel 231.60, 216.56Vanadium 292.40, 310.22AWinge, R. K., Fassel, V. A., Peterson, V. J., and Floyd, M. A., InductivelyCoupled Plasma Atomic Emission Spectroscopy: An Atlas of Spectral Information,Elsevier, NY, 1985. FIG. 1 Decomposition ApparatusD5708053Copyright by AST