ASTM D5708-2015 red 2653 Standard Test Methods for Determination of Nickel Vanadium and Iron in Crude Oils and Residual Fuels by Inductively Coupled Plasma (ICP) Atomic Emission Sp.pdf

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1、Designation: D5708 121D5708 15Standard 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 D5708; the number immediately following the designati

2、on 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 () indicates an editorial change since the last revision or reapproval.1 NOTESubsection X1.5 was corrected editorially

3、 in May 2015.1. Scope*1.1 These test methods cover the determination of nickel, vanadium, and iron in crude oils and residual fuels by inductivelycoupled plasma (ICP) atomic emission spectrometry. Two different test methods are presented.1.2 Test Method A (Sections 7 11 and 18 22)ICP is used to anal

4、yze a sample dissolved in an organic solvent. This testmethod uses oil-soluble metals for calibration and does not purport to quantitatively determine or detect insoluble particulates.1.3 Test Method B (Sections 12 22) ICP is used to analyze a sample that is decomposed with acid.1.4 The concentratio

5、n ranges covered by these test methods are determined by the sensitivity of the instruments, the amountof sample taken for analysis, and the dilution volume.Aspecific statement is given in 15.2. Typically, the low concentration limitsare a few tenths of a mg/kg. milligram per kilogram. Precision dat

6、a are provided for the concentration ranges specified in Section21.1.5 The values stated in SI units are to be regarded as standard. The values given in parentheses are for information only1.5.1 ExceptionThe values given in parentheses are for information only1.6 This standard does not purport to ad

7、dress all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D1193 Specific

8、ation for Reagent WaterD1548 Test Method for Vanadium in Heavy Fuel Oil1 (Withdrawn 1997)3D4057 Practice for Manual Sampling of Petroleum and Petroleum ProductsD4177 Practice for Automatic Sampling of Petroleum and Petroleum ProductsD5185 Test Method for Multielement Determination of Used and Unused

9、 Lubricating Oils and Base Oils by InductivelyCoupled Plasma Atomic Emission Spectrometry (ICP-AES)D6299 Practice for Applying Statistical Quality Assurance and Control Charting Techniques to Evaluate Analytical Measure-ment System PerformanceD7260 Practice for Optimization, Calibration, and Validat

10、ion of Inductively Coupled Plasma-Atomic Emission Spectrometry(ICP-AES) for Elemental Analysis of Petroleum Products and Lubricants3. Summary of Test Method3.1 Test Method AApproximately 10 g 10 g of the sample are dissolved in an organic solvent (WarningCombustible. Vaporis harmful.) to give a spec

11、imen solution containing 10 % (m/m) of sample. The solution is nebulized into the plasma, and the1 These test methods are under the jurisdiction of ASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility ofSubcommittee D02.03 on Elemental Analysis.Curr

12、ent edition approved Dec. 1, 2012Dec. 1, 2015. Published January 2013December 2015. Originally approved in 1995. Last previous edition approved in 20112012as D5708D5708 12111 DOI: 10.1520/D5708-12E01.10.1520/D5708-15.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM

13、 Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3 The last approved version of this historical standard is referenced on www.astm.org.This document is not an ASTM standard and is intended only

14、 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 that users consult prior editions as appropriate. In all cases only the current versio

15、nof the standard as published by ASTM is to be considered the official document.*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 States1intensities of the emitted light at wavel

16、engths characteristic of the analytes are measured sequentially or simultaneously. Theintensities are related to concentrations by the appropriate use of calibration data.3.2 Test Method BOne to 20 g 20 g of sample are weighed into a beaker and decomposed with concentrated sulfuric acid(WarningPoiso

17、n. Causes severe burns. Harmful or fatal if swallowed or inhaled.) by heating to dryness. Great care must be usedin this decomposition because the acid fumes are corrosive and the mixture is potentially flammable. The residual carbon is burnedoff by heating at 525C525 C in a muffle furnace. The inor

18、ganic residue is digested with nitric acid(WarningPoison. Causessevere burns. Harmful or fatal if swallowed or inhaled.), evaporated to incipient dryness, dissolved in dilute nitric acid, and madeup to volume. The solution is nebulized into the plasma of an atomic emission spectrometer. The intensit

19、ies of light emitted atcharacteristic wavelengths of the metals are measured sequentially or simultaneously. These intensities are related toconcentrations by the appropriate use of calibration data.4. Significance and Use4.1 These test methods cover, in single procedures, the determination of Ni, V

20、, and Fe in crude oils and residual oils. These testmethods complement Test Method D1548, which covers only the determination of vanadium.4.2 When fuels are combusted, vanadium present in the fuel can form corrosive compounds. The value of crude oils can bedetermined, in part, by the concentrations

21、of nickel, vanadium, and iron. Nickel and vanadium, present at trace levels in petroleumfractions, can deactivate catalysts during processing. These test methods provide a means of determining the concentrations ofnickel, vanadium, and iron.5. Purity of Reagents5.1 Reagent grade chemicals shall be u

22、sed in all tests. Unless otherwise indicated, it is intended that all reagents conform to thespecifications of the Committee onAnalytical Reagents of theAmerican Chemical Society where such specifications are available.4Other grades may be used, provided it is first ascertained that the reagent is o

23、f sufficiently high purity to permit its use withoutlessening the accuracy of the determination.5.2 When determining metals at concentrations less than 11 mg mg/kg, kg, use ultra-pure reagents.5.3 Purity of WaterUnless otherwise indicated, reference to water shall be understood to mean reagent water

24、 conforming toType II of Specification D1193.6. Sampling and Sample Handling6.1 The objective of sampling is to obtain a sample for testing purposes that is representative of the entire quantity. Thus, takesamples in accordance with the instructions in Practice D4057 or D4177. Do not fill the sample

25、 container more than two-thirdsfull.6.2 Prior to weighing, stir the sample and manually shake the sample container. If the sample does not readily flow at roomtemperature, heat the sample in a drying oven at 80C or at another safe temperature.TEST METHOD AICP WITH AN ORGANIC SOLVENT SPECIMEN SOLUTIO

26、N7. Apparatus7.1 Inductively Coupled Plasma Atomic Emission SpectrometerEither a sequential or simultaneous spectrometer, equippedwith a quartz torch and radio-frequency generator to form and sustain the plasma, is suitable.7.2 NebulizerThe use of a high-solids nebulizer is optional but strongly rec

27、ommended. This type of nebulizer minimizes theprobability of clogging. A concentric glass nebulizer can also be used.7.3 Peristaltic PumpThis pump is required for non-aspirating nebulizers and optional for aspirating nebulizers. The pumpmust achieve a flow rate in the range of 0.50.5 mLmin to 33 mL

28、mL/min. min. The pump tubing must be able to withstand atleast a 6 h 6 h exposure to the solvent. Fluoroelastomer copolymer tubing is recommended.57.4 Specimen Solution Containers, glass or plastic vials or bottles with screw caps having a capacity of appropriate size. Onehundred millilitre glass bo

29、ttles are satisfactory.4 Reagent Chemicals, American Chemical Society Specifications, American Chemical Society, Washington, DC. For Suggestions on the testing of reagents not listed bythe American Chemical Society, see Annual Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and th

30、e United States Pharmacopeia and NationalFormulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, MD.5 Fluoroelastomer copolymer is manufactured as Viton, a trademark owned by E. I. duPont de Nemours.D5708 1528. Reagents8.1 Dilution SolventMixed xylenes, o-xylene, tetralin and mixed paraffi

31、n-aromatic solvents are satisfactory. Solvent purity canaffect analytical accuracy when the sample contains low concentrations (typically, a few mg/kg) milligrams per kilogram) of theanalytes.8.2 Mineral OilA high-purity oil such as U.S.P. white oil.8.3 Organometallic StandardsPre-prepared multielem

32、ent concentrates containing 100100 mg mg/kg kg concentrations ofeach element are satisfactory.8.4 Quality Control (QC) Samples, preferably are portions of one or more liquid petroleum materials that are stable andrepresentative of the samples of interest. These QC samples can be used to check the va

33、lidity of the testing process as describedin Section 19.9. Preparation of Standards and Specimens9.1 BlankPrepare a blank by diluting mineral oil with dilution solvent. The concentration of mineral oil must be 10 % (m/m).Mix well.9.2 Check StandardUsing organometallic standards, mineral oil, and dil

34、ution solvent, prepare a check standard to containanalyte concentrations approximately the same as expected in the specimens. The concentration of oil in the check standard mustbe 10 % (m/m).9.3 Test SpecimenWeigh a portion of well-mixed sample into a container and add sufficient solvent to achieve

35、a sampleconcentration of 10 % (m/m). Mix well.9.4 Working StandardPrepare an instrument calibration standard that contains 1010 mg mg/kg kg each of vanadium, nickel,and iron. Combine the organometallic standard, dilution solvent and, if necessary, mineral oil so that the oil content of thecalibratio

36、n standard is 10 % (m/m).9.5 Quality Control (QC) SamplesWeigh a portion of the well-mixed QC sample into a container and add sufficient solventto achieve a sample concentration of 10 % (m/m).10. Preparation of Apparatus10.1 Consult Practice D7260 regarding the optimum operation of any ICP-AES syste

37、m.10.2 Consult the manufacturers instructions for the operation of the ICP instrument. This test method assumes that goodoperating procedures are followed. Design differences between instruments make it impractical to specify required parameters.10.3 Assign the appropriate operating parameters to th

38、e instrument taskfile so that the desired analytes can be determined.Parameters include: (1) element, (2) analytical wavelength, (3) background correction wavelengths (optional), (4) interelementcorrection factors (refer to 10.4), (5) integration time of 1 to 10 s, (6 ) two to five consecutive repea

39、t integrations. Suggestedwavelengths are listed in Table 1.10.4 Spectral InterferencesCheck all spectral interferences expected for the analytes. If interference corrections are necessary,follow the manufacturers operating guide to develop and apply correction factors.10.4.1 Spectral interferences c

40、an usually be avoided by judicious choice of analytical wavelengths. If spectral interferencescannot be avoided, the necessary corrections should be made using the computer software supplied by the instrument manufactureror by using the empirical method described in Test Method D5185.10.5 Consult th

41、e instrument manufacturers instructions for operating the instrument with organic solvents.10.6 During instrument warm-up, nebulize the blank solution. Inspect the torch for carbon build-up. When carbon build-upoccurs, replace the torch and adjust the operating conditions to correct the problem.TABL

42、E 1 Elements Determined and Suggested WavelengthsNOTE 1These wavelengths are suggestions and do not represent allpossible choices.AElement Wavelength, nmIron 259.94, 238.20Nickel 231.60, 216.56Vanadium 292.40, 310.22A Winge, R. K., Fassel, V.A., Peterson, V. J., and Floyd, M.A., Inductively CoupledP

43、lasmaAtomic Emission Spectroscopy:AnAtlas of Spectral Information, Elsevier,NY, 1985.D5708 15310.6.1 Carbon build-up within the torch can be caused by improperly adjusted argon flow rates, improper solution flow rates,and positioning the torch injector tube too close to the load coil. Carbon deposit

44、s can invalidate a calibration and extinguish theplasma.11. Calibration and Analysis11.1 Using the blank and working standard, perform a two-point calibration at the beginning of the analysis of each batch ofspecimens. Additional working standards can be used, if desired.11.2 Use the check standard

45、to determine if the calibration for each analyte is accurate. When the result obtained on the checkstandard is not within 65 % of the expected concentration for each analyte, take corrective action and repeat the calibration.11.3 Analyze the specimens in the same manner as the calibration standards

46、(that is, same integration time, plasma conditions,and so forth). Calculate concentrations by multiplying the concentration determined for the test specimen solution by the dilutionfactor. Calculation of concentrations can be performed manually or by computer when such a feature is available.11.4 Wh

47、en the measured intensities for the test specimen solution exceed the corresponding intensities for the working standard,either ensure that the calibration curve is linear to the concentration of the element in the test specimen solution or dilute the testspecimen solution with the blank solution an

48、d reanalyze.11.5 Analyze the check standard after every fifth specimen. If any result is not within 5 % of the expected concentration, takecorrective action, repeat the calibration, and reanalyze the specimen solutions back to the previous acceptable check standardanalysis.11.6 The use of spectral b

49、ackground correction is highly recommended, particularly when the test specimen solutions containlow concentrations of the analytes (typically less than 1 mg/kg). When concentrations are low, background changes, which canresult from variability in the compositions of test specimen solutions, can affect the accuracy of the analysis. Backgroundcorrection minimizes errors due to variable background intensities.TEST METHOD BICPAFTER ACID DECOMPOSITION OF SAMPLE12. Apparatus12.1 Refer to 7.1 7.4.12.2 Sample Decomposition Apparatus (opti