1、Designation: D7524 10 (Reapproved 2015)IP 568/08Standard Test Method forDetermination of Static Dissipater Additives (SDA) inAviation Turbine Fuel and Middle Distillate FuelsHighPerformance Liquid Chromatograph (HPLC) Method1This standard is issued under the fixed designation D7524; the number immed
2、iately following 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 () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This
3、test method covers the determination of staticdissipater additive (SDA) content of aviation turbine fuel andmiddle distillate fuels.1.2 The precision of this test method has been establishedfor aviation turbine fuel over the concentration range of1 mgL to 12 mgL. Higher concentrations can be determi
4、nedby dilution, but the precision of the test method will not apply.NOTE 1The SDA used to develop this test method was STADIS 4502for aviation fuels and STADIS 450 and 4252for middle distillates.1.3 The test method includes a procedure to concentrate thesulfonic acid component in the SDA prior to an
5、alysis.1.4 The test method only applies to SDAs that contain alkylsubstituted sulfonic acid.1.5 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.6 This standard does not purport to address all of thesafety concerns, if any, ass
6、ociated 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. Referenced Documents2.1 ASTM Standards:3D4057 Practice for Manual Sampling of Petroleum andPetro
7、leum ProductsD4177 Practice for Automatic Sampling of Petroleum andPetroleum Products2.2 ISO Standards:4EN ISO 3696 Water for Analytical Laboratory UseSpecifications and Test Methods2.3 Energy Institute Standards:5IP 568/08 Determination of the Static Dissipater Additives(SDA) in Aviation Turbine Fu
8、el and Middle DistillateFuelsHPLC Method3. Terminology3.1 Definitions:3.1.1 middle distillate fuels, ngeneric refinery/supplierterm that usually denotes a fuel primarily intended for use incompression ignition/diesel engine applications, and also innon-aviation gas turbine engines and other non-auto
9、motiveapplications such as a burner fuel.3.2 Definitions of Terms Specific to This Standard:3.2.1 aviation turbine fuel, nfuel used for powering jetand turbo-prop engine aircraft.3.2.2 conductivity improver additive, nmaterial added to afuel in very small amounts to increase its electrical conductiv
10、-ity and thereby reduce relaxation time.3.2.2.1 DiscussionConductivity improver additives arealso known as static dissipater additives (SDAs) or antistaticadditives.4. Summary of Test Method4.1 A solid phase extraction procedure is used to concen-trate the sulfonic acid component of SDApresent in an
11、 aviationturbine fuel or middle distillate fuel sample prior to analysis.A1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility ofSubcommittee D02.04.0C on Liquid Chromatography.Current edition approved A
12、pril 1, 2015. Published May 2015. Originallyapproved in 2010. Last previous edition approved in 2010 as D7524 10.DOI:10.1520/D7524-10R15.2Stadis 450 and 425 are registered trademarks marketed by Innospec, Inc.,Innospec Manufacturing Park, Oil Sites Road, Ellesmere Port, Cheshire Ch65 4EY,UK.3For ref
13、erenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.4Available from International Organization for Standardization (ISO),
14、 1, ch. dela Voie-Creuse, Case postale 56, CH-1211, Geneva 20, Switzerland, http:/www.iso.ch.5Available from Energy Institute, 61 New Cavendish St., London, WIG 7AR,U.K., http:/www.energyinst.org.uk.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. U
15、nited States1fixed volume of the concentrated test fraction is injected into acalibrated high performance liquid chromatograph.An analyti-cal column is used to separate the sample components of thetest fraction by polarity.4.2 The analytical column is attached to a liquid chroma-tography detector wh
16、ere the sulfonic acid components arereadily detected by UV absorption as they elute from thecolumn. The electronic signal from the liquid chromatographydetector is continually monitored by a chromatography datasystem. The amplitudes of the signal (peak area) from thesulfonic acids are compared with
17、those obtained from previ-ously measured calibration standards in order to calculate thepercent m/V SDA present in the sample.4.3 The test method only applies to SDAs that contain alkylsubstituted sulfonic acids.5. Significance and Use5.1 This test method will allow the determination of staticdissip
18、ater additive in jet and middle distillate. These additivesreduce the hazardous effects of static electricity generated bytransfer and movement of jet and middle distillate fuels.6. Apparatus6.1 High Performance Liquid Chromatograph (HPLC)Any HPLC capable of pumping an isocratic mobile phase atflow
19、rates between 0.1 mLmin and 1.5 mLmin, with aprecision better than 0.5 % and a pulsation of 1 % full scaledeflection under the test method conditions.6.2 Variable Wavelength Ultraviolet Photometric Detectoror Photometric Diode Array DetectorCapable of operation at225 nm and 234 nm.6.3 Manual or Auto
20、matic Sample Injection ValveCapableof injecting 10 L to 25 L, using either partial or full loopmode, with a repeatability 61%.6.3.1 An equal and constant volume of the calibration andsample solutions is injected into the chromatograph. Bothmanual and automatic sample injection systems (using eitherc
21、omplete or partial filling of the sample loop) will, when usedcorrectly, meet the repeatability requirements specified in 6.3.NOTE 2When using the partial loop-filling mode, it is recommendedthat the injection volume should be less than half the total loop volume.For complete filling of the loop, be
22、st results are obtained by overfilling theloop at least six times.6.4 Chromatography Data SystemAny data system can beused, provided it is compatible with the liquid chromatographydetector, has a minimum sampling rate of 1 Hz, and is able tomeasure peak areas and retention times and perform post-run
23、data processing such as baseline correction and re-integration.6.5 Analytical Column6Any stainless steel HPLC columnpacked with C6alkyl-bonded reversed-phase, 5 m particlesize, 250 mm 4.6 mm ID is suitable, provided that it meetsthe resolution requirements specified in 9.3.6.6 HPLC Column OvenAny su
24、itable HPC column ovenblock heating or air circulating) capable of maintaining aconstant temperature of 61 C within the range from 20 C to40 C.NOTE 3Alternative forms of temperature control are permitted, forexample, temperature-controlled laboratories.6.7 Analytical BalanceAccurate to 60.0001 g.6.8
25、 Solid Phase Extraction (SPE) Columns Reservoirs6Amino bonded silica, 6500 mg (A) or 100 mg (B) capacity.6.8.1 Reservoirs with ConnectorsApproximately 60 mLcapacity and connectors.6.9 Solid Phase Extraction Vacuum ManifoldOptional.6.10 Volumetric FlasksClassA, of 2 mL, 5 mL, 10 mL, 25mL, and 100 mL
26、capacity.6.11 Graduated PipetteClass A, of 1 mL, 2 mL, 10 mL,and 50 mL capacity. Capable of delivering volumes of therange 0.5 mL to 4.0 mL with an accuracy of 60.0005 mL.6.12 Measuring Cylinder50 mL and 500 mL capacity.6.13 pH meter.7. Reagents and Materials7.1 Dinonylnaphthalene Sulfonic Acid (DIN
27、NSA)50 %(m/m) solution in heptane.7.2 Dodecylbenzene Sulfonic Acid (DDBSA)70 % (m/m)solution in 2-propanol.7.3 TetrahydrofuranHPLC grade. (WarningHPLCgrade tetrahydrofuran does not contain inhibitor, hence explo-sive peroxides may form. Highly flammable and may causeirritation by inhalation, ingesti
28、on or skin contact.)7.4 Hydrochloric Acid37 %.7.5 MethanolHPLC grade. (Warning Methanol ishighly flammable and toxic by inhalation, ingestion or skincontact.)7.6 Methanolic Hydrochloric AcidMix approximately 1mL of hydrochloric acid (see 7.4) with approximately 9 mL ofmethanol (see 7.5).7.7 Orthopho
29、sphoric Acid.7.8 Sodium Hydroxide Pellets.7.9 Sodium Hydroxide SolutionApproximately 1 M. Dis-solve approximately4gofsodium hydroxide (see 7.8)inapproximately 100 mL of water.7.10 Buffered Phosphoric AcidAdd approximately 2 mLof orthophosphoric acid (see 7.7) to approximately 1l mL ofwater and buffe
30、r to 2.5 pH using sodium hydroxide solution(see 7.9).7.11 IsohexaneHPLC grade. (Warning Isohexane ishighly flammable, and may cause irritation by inhalation,ingestion or skin contact.)7.12 Solid Phase Extraction (SPE) Columns andCartridgesAmino-bonded silica, 500 mg and 100 mg.6The sole source of su
31、pply of the apparatus known to the committee at this timeis Waters Corp. 34 Maple St., Milford, MA 01757. If you are aware of alternativesuppliers, please provide this information to ASTM International Headquarters.Your comments will receive careful consideration at a meeting of the responsibletechn
32、ical committee,1which you may attend.D7524 10 (2015)27.13 Mobile PhaseMix approximately 400 mL methanol(see 7.5), approximately 400 mL THF (see 7.3), and approxi-mately 50 mL of buffered phosphoric acid (see 7.10).7.14 NitrogenOptional.NOTE 4It is recommended practice to degas HPLC mobile phasebefor
33、e use; this can be done conveniently, on-line or off-line, by heliumsparging, vacuum degassing, or ultrasonic agitation.Afailure to degas themobile phase may lead to negative peaks.7.15 Calibration Stock SolutionsAccurately weigh, to thenearest 0.0001 g, between 0.078 g and 0.082 g of DINNSAsolution
34、 (7.1) into a 100 mL volumetric flask and make up tothe mark with heptane or mobile phase (7.13). Accuratelyweigh, to the nearest 0.0001 g, between 0.028 g to 0.032 g ofDDBSA solution (7.2) into a 100 mL volumetric flask andmake up to the mark with heptane or mobile phase (7.13).7.16 Calibration Sta
35、ndardsFrom the calibration stocksolutions (7.15), prepare a set of five calibration standards inthe mobile phase (7.13) to cover the concentration rangesindicated in the table:SPE Column Size DINNSA DDBSA500 mg 0.8 mg/mL to 16mg/mL0.7 mg mL to 8.5mg/mL100 mg 0.32 mg/mL to 9mg/mL0.35 mg mL to4.5 mg m
36、LNOTE 5A suggested procedure to prepare these standards is given inAnnex A1.7.17 Calibration Check Solutions2.0 mgL DINNSA and2.8 mgL DBSA.7.17.1 Prepare a 500 mgL DINNSA solution by accuratelyweighing, to the nearest 0.0001 g, about 0.05 g DINNSA (7.1)into a 50 mL volumetric flask and making up to
37、the mark withheptane. Pipette 1 mL of this solution into a 25 mL volumetricflask and make up to the mark with heptane (20 mgLDINNSA solution). Pipette 1 mL of the 20 mgL DINNSAsolution into a 10 mL volumetric flask and make up to volumewith mobile phase (7.13) to give a 2.0 mgL check solution.7.17.2
38、 Prepare a 700 mgL DDBSA solution by accuratelyweighing, to the nearest 0.0001 g, 0.05 g DDBSA (7.2) into a50 mL volumetric flask and making up to the mark withheptane. Pipette 1 mL of this solution into a 25 mL volumetricflask and make up to the mark with heptane (28 mgL DDBSAsolution). Pipette 1 m
39、L of the 28 mg/L DDBSA solution intoa 10 mL volumetric flask and make up to volume with mobilephase (7.13) to give a 2.8 mgL check solution.7.18 WaterGrade 3 of EN ISO 3696.8. Sampling8.1 Use only representative samples obtained as describedin Practice D4057 or D4177, unless otherwise specified.9. S
40、ample Preparation9.1 Clamp the SPE column, 6.8(A) or 6.8(B), vertically orattach to a vacuum manifold if used. Add a 60 mL reservoir tothe 500 mg SPE column (6.8(A) using a connector (6.8.1); the100 mg SPE column has an integral reservoir.9.2 With a pipette, transfer the test specimen (see Table 1)t
41、othe SPE reservoir and allow the fuel to percolate through thecolumn under gravity or vacuum at a flow rate of 2 mLmin orless. Discard the eluate.9.3 After all the fuel has eluted from the SPE column, rinsethe reservoir and SPE adsorbent with portions of isohexane (orheptane) and then methanol, disc
42、arding the eluate (see Table1).9.4 Elute the sulfonic acid (DINNSA or DDBSA) from the100 mg or 500 mg SPE column using approximately 2 mL or5 mL of mobile phase (7.13), respectively, and collect theeluate in a 2 mL or 5 mL volumetric flask (6.10), making up tothe mark with mobile phase (7.13) if nec
43、essary. Replacestopper in volumetric flask and shake well.9.5 Sample and eluent volumes are summarized in Table 1.10. Preparation of Apparatus10.1 Set up the pump, injector, detector, and data systemaccording to the manufacturers instructions. Set the UVdetector to 234 nm for DINNSA and 225 nm for D
44、DBSA.10.2 Install the HPLC column and set the mobile phase flowrate to 0.5 mLmin.NOTE 6Set the temperature of the column oven, if used, to at least10 C above ambient, for example, 40 C.10.3 When operating conditions are steady, inject a fixedvolume (10 L to 25 L) of the middle calibration standard(7
45、.16), and ensure the chromatogram resembles those shown inFig. 1 (DINNSA) or Fig. 2 (DDBSA).NOTE 7The sulfonic acid peak around 4 min may exhibit somebroadening due to the presence of isomers but no fine structure.NOTE 8Small adjustments in the buffered phosphoric acid content ofthe mobile phase may
46、 improve the chromatographic profile of the sulfonicacid.10.4 Inject a fixed volume (10 L to 25 L) of the lowestconcentration calibration standard (7.16) to check systemsensitivity. The detector shall have a signal to noise ratio (S/N)greater than 10 for the lowest concentration calibration stan-dar
47、d; increase the injection volume if necessary.10.5 Inject the same volume (10 L to 25 L) of middlecalibration standard (7.16) five times to check system repeat-ability (less than 1 %).10.6 Inject the same volume (10 L to 25 L) of all calibra-tion standards (7.16) to check system linearity (correlati
48、onco-efficient greater than 0.995).10.7 Inject the same (10 L to 25 L) of the highestconcentration standard (7.16) followed by blank (mobilephase) injection to check for analyte carryover (less than 0.05%).TABLE 1 SPE Sample, Wash, and Elution Volumes500 mgSPE Column100 mgSPE ColumnSample volume 50
49、mL 10 mLIsohexane/heptane wash 2 mL 5 mL 2 mL 2 mLMethanol wash 5 mL 2 mLDINNSA/DDBSA eluate 5 mL 2 mLD7524 10 (2015)310.8 Determination of Injection VolumeWhen operatingconditions are steady, as indicated by a stable horizontalbaseline of the liquid chromatography detector, inject a fixedvolume (10 L to 25 L) of the lowest calibration standard (E)and record the chromatogram with the chromatography datasystem to check system sensitivity. Select a fixed injectionvolume that provides a de
