1、Designation: D3605 16D3605 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 cas
2、e 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. Scope*1.1 This test method covers the determination of sodium, lead, calcium, and vanadium in Specif
3、ication D2880 Grade Nos. 0-GTthrough 4-GT fuels at 0.5 mgkg level for each of the elements. This test method is intended for the determination of oil-solublemetals and not waterborne contaminants in oil-water mixtures.1.1.1 Test Method D6728 is suggested as an alternative test method for the determi
4、nation of these elements in SpecificationD2880.1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibi
5、lityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.1.4 This international standard was developed in accordance with internationally recognized principles on standardizationestablished in the Deci
6、sion on Principles for the Development of International Standards, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D2880 Specification for Gas Turbine Fuel OilsD4057 Practice for Manual Sampling o
7、f Petroleum and Petroleum ProductsD4177 Practice for Automatic Sampling of Petroleum and Petroleum ProductsD6728 Test Method for Determination of Contaminants in Gas Turbine and Diesel Engine Fuel by Rotating Disc ElectrodeAtomic Emission Spectrometry3. Summary of Test Method3.1 The samples are prep
8、ared to conform with the requirements of the method of standard additions, which is selected to obviateproblems encountered with the direct analysis of typical gas turbine fuels that exhibit significant variations in physical properties.Different, but known, amounts of analyte are added to two porti
9、ons of sample. These, together with the unaltered sample, areburned in the flame of an atomic absorption instrument that measures light absorption by the atomized metals. The analysis of thesample portions with added analyte provides the calibration information necessary to calculate the analyte con
10、tent of the unalteredsample.3.2 Lead is determined by atomic absorption in a premixed air-acetylene flame, and sodium is determined by atomic absorptionor atomic emission in a premixed air-acetylene flame. Calcium and vanadium are determined by atomic absorption or atomicemission in a premixed nitro
11、us oxide-acetylene flame.3.3 Most experience with this test method has been in the atomic absorption mode, although flame emission has been usedsuccessfully. Details in the subsequent sections are written for the atomic absorption mode. If the flame emission mode is used,1 This test method is under
12、the jurisdiction ofASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricantsand is the direct responsibility of SubcommitteeD02.03 on Elemental Analysis.Current edition approved July 1, 2016June 1, 2017. Published July 2016June 2017. Originally approved in 1977. Last previous edition ap
13、proved in 20112016 asD3605 00 (2011).D3605 16. DOI: 10.1520/D3605-16.10.1520/D3605-17.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary
14、page on the ASTM website.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 tha
15、t 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.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West C
16、onshohocken, PA 19428-2959. United States1minor details in the subsequent sections must be altered to conform to standard practice for flame emission spectroscopy. Theprecision statement applies only to the atomic absorption mode.NOTE 1Some GT fuel users may wish to determine potassium in addition t
17、o other metals included in this method. Potassium can be determined ina manner similar to that for sodium using a potassium hollow cathode lamp, (unless flame emission mode is used) a wavelength of 766.4 mm, and anappropriate organo-potassium standard. Precision data for potassium have not been dete
18、rmined.4. Significance and Use4.1 Knowledge of the presence of trace metals in gas turbine fuels enables the user to predict performance and, when necessary,to take appropriate action to prevent corrosion.5. Apparatus5.1 Atomic Absorption Spectrophotometer, capable of measuring radiation over the wa
19、velength range from 280 nm to 600 nm.The instrument must be capable of measuring low-level signals (approximately 1 % absorption or 0.004 absorbance unit permilligram per litre vanadium). The instrument should also be equipped as follows.5.1.1 Burner, with variable nebulizer and auxiliary oxidant su
20、pply to reduce non-atomic absorption from unburnedhydrocarbons 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 multiple-slot, capable of supporting an air-acetylene flame.5.1.2 Electronic Detection System, capable o
21、f reading to the nearest 0.1 % absorption or 0.0004 absorbance.5.1.2.1 The text describes the measurement of absorption signals that is, either percent absorption or absorbance. Forinstruments reading in percent absorption, absorption signals of 0.1 % absorption must be measurable. For instruments r
22、eading inabsorbance, signals of 0.0004 absorbance must be measurable.5.1.3 Hollow Cathode Lamp Power Supply, regulated to minimize drift.5.1.4 Monochromator, capable of resolving the 318.34 nm 318.40 nm vanadium doublet from the 318.54 nm vanadium line.5.1.5 Hollow Cathode Lamps, one each for calciu
23、m, sodium, lead, and vanadium.NOTE 2Electrodeless-discharge lamps can be an acceptable alternative, but the precision of this method was determined with hollow cathode lamps.5.1.6 When the instrument has flame-emission capability, the emission technique can be used for the analyses of sodium,calcium
24、, and vanadium.5.2 Volumetric Flasks, 25 mL.5.3 Glass Vials, 40 mL, screw-cap type, polyethylene-lined caps.5.4 Syringe, 100 L, Hamilton type or equivalent.6. Reagents6.1 Purity of ReagentsReagent grade chemicals shall be used in tests. Unless otherwise indicated, it is intended that allreagents con
25、form to the specifications of the Committee on Analytical Reagents of the American Chemical Society where suchspecifications are available.3 Other grades may be used, provided it is ascertained that the reagent is of sufficiently high purity topermit its use without lessening the accuracy of the det
26、ermination.6.2 1,2,3,4-tetrahydronaphthalene,4practical grade, analyte-sterile.NOTE 3Analyte-sterile 1,2,3,4-tetrahydronaphthalene can be prepared by extracting a portion of tetralin with an equal amount of hydrochloric acidin a covered screw-cap vial. Heat the vial on a steam bath for 1 h and shake
27、 the vial for 1 h. If the acid extracted 1,2,3,4-tetrahydronaphthalene andunextracted 1,2,3,4-tetrahydronaphthalene give indistinguishable absorption signals for each of the analytes under optimal experimental conditions, theunextracted 1,2,3,4-tetrahydronaphthalene can be used throughout this metho
28、d.6.3 Organometallic StandardsOil-soluble salts of sodium, lead, calcium, and vanadium of known concentration.56.4 Mixed StandardPrepare a mixed standard containing 250 mgL each of sodium, lead, calcium, and vanadium bydissolving the appropriate amounts of organometallic standards in 1,2,3,4-tetrahy
29、dronaphthalene and making the requireddilutions. Prepare fresh daily, as needed.3 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 Analar Standards for La
30、boratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia and NationalFormulary, U.S. Pharmaceutical Convention, Inc. (USPC), Rockville, MD.4 Tetralin (1,2,3,4-tetrahydronaphthalene), manufactured by E. I. duPont de Nemours and Co., has been found satisfactory. If you are
31、 aware of alternative suppliers, pleaseprovide this information to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of the responsible technical committee,1whichyou may attend.5 Conostan standards, available from Conostan Division, Continental Oil Co., P
32、onca City, OK 74601, were used in determining the precision quoted in this method. Otherstandards are available from the Office of Standard Reference Materials, Room B314, Chemistry Bldg., National Institute of Standards and Technology, Washington, DC20234, and from Angstrom, Inc., P. O. Box 252, Be
33、lleville, MI 48111, but the precision statement may or may not apply to results obtained with these standards.D3605 1726.5 Quality Control Samples, preferably are portions of one or more liquid petroleum materials that are stable and representativeof the samples of interest. These QC samples can be
34、used to check the validity of the testing process as described in Section 8.7. Sampling7.1 Samples shall be taken in accordance with the instructions in Practice D4057 or D4177.8. Procedure8.1 Fill two clean 25 mL volumetric flasks to the line with sample. With the microlitre syringe add 50 L of mix
35、ed standard toone flask and 100 L to the other. Touch the needle of the syringe to the inner wall of the flask to ensure quantitative transfer ofthe standard. Invert and mix the contents. (The two flasks are now spiked with 0.5 mgL and 1.0 mgL of sodium, lead, calcium,and vanadium).Alternatively, we
36、igh 25.0 g of sample into each of two clean disposable glass vials and add the standard in the samemanner. (The two vials are now spiked with 0.5 mgkg and 1.0 mgkg of sodium, lead, calcium, and vanadium.)8.2 Prepare a third spiked sample by adding approximately 1 mLof the mixed standard to approxima
37、tely 25 mLof sample. Thissolution serves only to aid in establishing satisfactory operating conditions for the atomic absorption instrument.8.3 Establish the atomic absorption instrument operating conditions, which are recommended by the manufacturer, and considerthe following special points. Select
38、 the mode, flame gases, and spectral lines from the information presented in Table 1.8.4 Analysis:8.4.1 With the atomic absorption instrument in operation for monitoring lead absorption and with 1,2,3,4-tetrahydronaphthalenenebulizing, zero the instrument. Aspirate into the flame the third spiked sa
39、mple described in 8.2 and note the net lead absorptionsignal. Optimize experimental conditions by adjusting the burner position (relative to the hollow cathode beam), the flow rates ofthe fuel and oxidant gases, and the sample aspiration rate until the net lead absorption signal maximizes. Re-zero t
40、he instrumentwith 1,2,3,4-tetrahydronaphthalene nebulizing, and consecutively introduce into the flame the unaltered sample and the two spikedsamples, with 1,2,3,4-tetrahydronaphthalene nebulizing between each sample. Record the absorption signal of each sample and ofeach blank between samples.8.4.1
41、.1 At optimal experimental conditions, the analyte concentration that accounts for 1 % absorption should be approximately1 mgL. L or 1 mgkg. The percent absorption to concentration ratio must be near unity in order to achieve the lower limits ofdetection that are required. This note does not apply t
42、o flame emission measurements.8.4.2 With the atomic absorption instrument in operation for monitoring vanadium absorption and with 1,2,3,4-tetrahydronaphthalene nebulizing, zero the instrument. Introduce into the flame the third spiked sample described in 8.2. Recordthe net vanadium absorption signa
43、l. Optimize the experimental conditions as in 8.4.1. Re-zero the instrument with 1,2,3,4-tetrahydronaphthalene nebulizing and consecutively introduce into the flame the unaltered sample and the two spiked samples.Record the absorption signal of each sample and of each 1,2,3,4-tetrahydronaphthalene b
44、lank between samples.8.4.3 With the atomic absorption instrument in operation for monitoring sodium absorption, zero the instrument with1,2,3,4-tetrahydronaphthalene nebulizing, and consecutively introduce into the flame the unaltered sample and the two spikedsamples. Record the absorption signal of
45、 each sample and of each 1,2,3,4-tetrahydronaphthalene blank between samples.NOTE 4For determining sodium and calcium, the maximization of absorption or emission signals is not critical.8.4.4 With the atomic absorption instrument in operation for monitoring calcium absorption, zero the instrument wi
46、th1,2,3,4-tetrahydronaphthalene nebulizing, and consecutively introduce into the flame the unaltered sample and the two spikedsamples. Record the absorption signal of each sample and of each 1,2,3,4-tetrahydronaphthalene blank between samples.9. Calculation9.1 For each absorption signal, calculate t
47、he net absorption signal as follows:a 5A 2b11b2!/2# (1)where:a = net absorption signal,A = observed absorption signal,TABLE 1 Experimental ConditionsElement Mode Wavelength, nm Fuel OxidantNa Absorption 589.6 C2H2 airNa Emission 589.6 C2H2 airPb Absorption 283.3 C2H2 airCa Absorption 422.7 C2H2 N2OC
48、a Emission 422.7 C2H2 N2OV Absorption 318.34318.40 C2H2 N2OV Emission 437.9 C2H2 N2OD3605 173b1 = blank signal before the sample, andb2 = blank signal after the sample.NOTE 5Blank corrections are usually small. If a large drift in blank signals is observed during a series of measurements, some exper
49、imental parameteris out of control. The cause of the variation should be corrected, and the measurements repeated.9.2 For each element in turn, calculate sensitivities as follows:S0.552a12a2! (2)S1.05a32a2! (3)S 5S0.51S1.0!/2 (4)where:S0.5 = sensitivity for the 0.5 mgL or 0.5 mgkg spiked sample,S1.0 = sensitivity for the 1.0 mgL or 1.0 mgkg spiked sample,S = average sensitivity,a1 = net absorption signal for the 0.5 mgL or 0.5 mgkg spiked sample,a2 = net absorption signal for the unaltered sample, anda3 = net absorption signal for the 1.0 mgL
