ASTM D3703-2007(2012) Standard Test Method for Hydroperoxide Number of Aviation Turbine Fuels Gasoline and Diesel Fuels《测定航空涡轮燃料、汽油和柴油燃料中氢过氧化物值的标准试验方法》.pdf

《ASTM D3703-2007(2012) Standard Test Method for Hydroperoxide Number of Aviation Turbine Fuels Gasoline and Diesel Fuels《测定航空涡轮燃料、汽油和柴油燃料中氢过氧化物值的标准试验方法》.pdf》由会员分享，可在线阅读，更多相关《ASTM D3703-2007(2012) Standard Test Method for Hydroperoxide Number of Aviation Turbine Fuels Gasoline and Diesel Fuels《测定航空涡轮燃料、汽油和柴油燃料中氢过氧化物值的标准试验方法》.pdf（4页珍藏版）》请在麦多课文档分享上搜索。

1、Designation: D3703 07 (Reapproved 2012)Standard Test Method forHydroperoxide Number of Aviation Turbine Fuels, Gasolineand Diesel Fuels1This standard is issued under the fixed designation D3703; the number immediately following the designation indicates the year oforiginal adoption or, in the case o

2、f 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.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 This test met

3、hod covers the determination of the hy-droperoxide content expressed as hydroperoxide number ofaviation turbine, gasoline and diesel fuels.1.2 The range of hydroperoxide number included in theprecision statement is 0 to 50 mg/kg active oxygen as hydrop-eroxide.1.3 The interlaboratory study to establ

4、ish the precision ofthis test method consisted of spark-ignition engine fuels(regular, premium and California Cleaner-Burning gasoline),aviation gasoline, jet fuel, ultra low sulfur diesel, and biodiesel.However, biodiesel was not included in the precision calcula-tion because of the large differenc

5、es in results within labs andbetween labs.1.4 This test method detects hydroperoxides such as t-butylhydroperoxide and cumene hydroperoxide. It does not detectsterically-hindered hydroperoxides such as dicumyl and di-t-butyl hydroperoxides1.5 Di-alkyl hydroperoxides added commercially to dieselfuels

6、 are not detected by this test method.1.6 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.7 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the

7、user of this standard to consult andestablish appropriate safety and health practices and deter-mine the applicability of regulatory limitations prior to use.For specific warning statements, see 7.3, 7.6, 9.2, and AnnexA1.2. Referenced Documents2.1 ASTM Standards:2D1193 Specification for Reagent Wat

8、erD4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD6447 Test Method for Hydroperoxide Number of AviationTurbine Fuels by Voltammetric Analysis2.2 Other Standards:CRC Report No. 559 Determination of the HydroperoxidePotential of Jet Fuels34500-C1 B. Iodometric Method IStandard Me

9、thods forthe Examination of Water and Wastewater43. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 hydroperoxide, norganic peroxide having the gener-alized formula ROOH.3.1.1.1 DiscussionThis test method detects hydroperox-ides such as t-butyl hydroperoxide (CH3)3COOH and cumene

10、hydroperoxide C6H5C(CH3)2OOH. It does not detectsterically-hindered hydroperoxides such as dicumyl and di-t-butyl hydroperoxides.3.1.2 hydroperoxide number, nan indication of the quan-tity of oxidizing constituents present in certain liquid fuels asdetermined by this test method.3.1.2.1 DiscussionTh

11、e higher the quantity of oxidizingconstituents in the fuels, the higher the hydroperoxide number.4. Summary of Test Method4.1 A quantity of sample dissolved in 2,2,4-trimethylpentane is contacted with aqueous potassium iodidesolution. The hydroperoxides present are reduced by the1This test method is

12、 under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.05 on Properties of Fuels, Petroleum Coke and Carbon Material.Current edition approved June 1, 2012. Published July 2012. Originally approvedin 1978. Last previous ed

13、ition approved in 2007 as D3703071. DOI: 10.1520/D3703-07R12.2For referenced 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.

14、3Available from the Coordinating Research Council, Inc., 219 Perimeter CenterParkway, Atlanta, GA 30346.4Published by the American Health Assoc., the American Water Works Assoc.and Water Environment Federation. Available from American Public HealthPublication Sales, P. O. Box 753, Waldorf, MD 206040

15、753.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1potassium iodide. An equivalent amount of iodine is liberated,which is titrated with an aqueous sodium thiosulfate solution.The results are calculated as milligrams of hydroperoxide

16、perkilogram of sample expressed as hydroperoxide number. (SeeNote 1.)NOTE 1The original standard D3703 was published in 1978 asStandard Test Method for Peroxide Number of Aviation Turbine Fuels.This test method originally used carbon tetrachloride (CCl4), which wasdetermined to be carcinogenetic. CC

17、l4was later replaced with 1,1,2-trichloro-1,2,2 trifluoroethane. 1,1,2-trichloro-1,2,2-trifluoroethane is anozone depleting substance. The use of an ozone depleting substanceprecludes its use by many operators.5. Significance and Use5.1 The magnitude of the hydroperoxide number is anindication of th

18、e quantity of oxidizing constituents present.Deterioration of the fuels results in the formation of hydrop-eroxides and other oxygen-carrying compounds. The hydrop-eroxide number measures those compounds that will oxidizepotassium iodide.5.2 The determination of the hydroperoxide number ofaviation t

19、urbine fuels, gasoline and diesel is significant becauseof the adverse effect of hydroperoxide upon certain elastomersin the fuel systems.5.3 The determination of hydroperoxide number of gasolineis significant because hydroperoxides have been demonstratedto decrease both Research and Motor Octane Nu

20、mbers. Inaddition, hydroperoxides have adverse effects on certain fuelsystem components.5.4 The determination of hydroperoxide number of dieselfuel is significant because hydroperoxides have been demon-strated to increase the Cetane Number. In addition, hydroper-oxides have adverse effects on certai

21、n fuel system components.6. Apparatus6.1 Iodine Number Flask, 250 mL, glass-stoppered.6.2 Burettes, 10-mL, 25-mL, Class A with polytetrafluoro-ethylene (PTFE) stop cock.6.3 Volumetric Flasks, 100-mL and 1000-mL, 2000 mLClass A with PTFE stoppers.6.4 Mixing Cylinders, 100 mL and 500-mL, glass-stopper

22、ed.6.5 Microburet, 10-mL, Class A.6.6 Analytical Balance, capable of weighing to the nearestmilligram.6.7 Brown Bottles, 100-mL, 300-mL, 1000-mL with screwcaps with inert inserts.6.8 Measuring Cylinders, 25-mL and 100-mL.7. Reagents7.1 Purity of ReagentsReagent grade chemicals shall beused in all te

23、sts. Unless otherwise indicated, it is intended thatall reagents shall conform to the specifications of the Commit-tee on Analytical Reagents of the American Chemical Society,where such specifications are available.5Other grades may beused, provided it is first ascertained that the reagent is ofsuff

24、iciently high purity to permit its use without lessening theaccuracy of the determination.7.1.1 Commercially available solutions already preparedmay be used in place of laboratory preparations, if they meetthe method requirements.7.2 Purity of WaterUnless otherwise indicated, referencesto water shal

25、l be understood to mean reagent water that meetsthe requirement of Type I, II, or III of Specification D1193.7.3 Acetic Acid SolutionMix 4 mL of concentrated hydro-chloric acid (HCl, sp gr 1.19) with 996 mL of glacial aceticacid (CH3COOH). (WarningPoison. Corrosive. Combus-tible. Can be fatal if swa

26、llowed. Causes severe burns. Harmfulif inhaled. See A1.2).7.4 Nitrogen Gas, 99.9995% Minimum purity7.5 Carbon Dioxide, 99.9995% Minimum purity7.6 2,2,4-trimethylpentane (iso-octane), (WarningFlammable, dangerous fire risk. Toxic by injection and inha-lation. See A1.1.)7.7 Potassium Dichromate Soluti

27、on, Standard (0.1 N), ACSreagent grade. Dissolve 2.452 g of the dried potassium dichro-mate (K2Cr2O7) in water and dilute to 500 mL in a volumetricflask. This solution is 0.1 N. As an alterative, the lab may usecommercially prepared solution.7.8 Potassium Dichromate Solution, Standard (0.01 N),(Warn

28、ingAvoid contact with eyes and skin and avoidbreathing of dust)Dilute 100 mL of 0.1 N K2Cr2O7solutionwith water to 1000 mL in a volumetric flask.)7.9 Potassium Iodide Solution, Dissolve 120 g of potassiumiodide (KI) in 100 mL of water. Larger quantities of solutionmay be prepared, provided the conce

29、ntration of KI in water isequivalent. Protect the solution from sunlight by storing inbrown bottles and blanketed with nitrogen or carbon dioxide.Discharge any color from this solution by placing 1 mL of KIsolution, 50 mL of water, and 5 mL of starch solution in a300-mL flask and blanketing with nit

30、rogen or carbon dioxide.If a blue color develops, add 0.005 N Na2S2O3solution from amicroburet until color just disappears. Add a sufficient quantityof Na2S2O3solution, thus determined, to the main KI solutionto convert all free iodine to iodide. When properly prepared, 1mL of KI solution should not

31、 turn blue when starch solution isadded, but with starch plus one drop of 0.01 N K2Cr2O7solution plus two drops of HCl, the blue color should develop.Store this solution under nitrogen or carbon dioxide.7.10 Sodium Thiosulfate Solution, Standard (0.1 N), Dis-solve 12.5 g of sodium thiosulfate (Na2S2

32、O35H2O) plus 0.1 gof sodium carbonate (Na2CO3) in 500 mL of water (theNa2CO3is added to stabilize the Na2S2O3solution). Let this5Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For Suggestions on the testing of reagents notlisted by the American

33、 Chemical Society, see Annual Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.D3703 07 (2012)2solution stand a week or more before using. Standardizeagainst 0.1 N K2Cr

34、2O7solution, using any appropriate tech-nique, such as the one indicated in 4500-C1 B. Standardize atintervals frequent enough to detect changes of 0.0005 innormality.7.11 Sodium Thiosulfate Solution, Standard (0.005 N), Pre-pare a twenty-fold dilution of the 0.1 N Na2S2O3solutionprepared in 7.10, u

35、sing a volumetric flask. One way toaccomplish this is to dilute 100 mL of 0.1 N Na2S2O3solutionswith water to 2000 mL in a volumetric flask. Prepare thissolution fresh with restandardized 0.1 N Na2S2O3solutionwhen any change of 0.0005 or over in normality is detected.7.12 Starch Solution, Make a pas

36、te of6gofarrowrootstarch or soluble iodometric starch with cold water. Pour thepaste into 1 L of boiling water. Add 20 g of potassiumhydroxide (KOH), mix thoroughly, and allow to stand forapproximately 2 h. Add 6 mL of glacial acetic acid. Mixthoroughly and then add sufficient HCl (sp gr 1.19) to ad

37、justthe pH value of the solution to 4.0. Store in a glass-stopperedbottle. Starch solution prepared in this manner can remainchemically stable for up to one year.7.13 t-Butyl Hydroperoxide, (CH3)3COOH, 90% minimumpurity, Make working standards with iso-octane to cover therange of the expected result

38、s.8. Sampling8.1 Samples shall be taken in accordance with the proce-dures described in Practice D4057.8.2 If samples cannot be tested immediately, they should bestored in a refrigerator at a temperature between 1 and 4C (35and 40F). Bring the sample to room temperature beforetesting.9. Procedure9.1

39、 Select the appropriate weight of sample from the fol-lowing table:Estimated Peroxide Number,mg/kgSample Mass, g0to10 5011 to 30 3531 to 50 2551 to 80 (Note 2) 1081 to 100 5NOTE 2The precision statement was based up to 50 mg/kg oxygen.The precision might not apply for samples greater than 50 mg/kg.9

40、.2 Weigh the sample, accurate to 1 mg, into a 250-mLiodine flask that has been flushed with nitrogen or carbondioxide. With a measuring cylinder, add 25 mL of 2,2,4-trimethylpentane (WarningSee A1.1). Pass a vigorous flowof nitrogen or carbon dioxide through the solvent for at least 1min; then, with

41、out stopping the gas flow, add 20 mL of aceticacid solution and reduce the flow of gas so that the rate is onebubble per second. Add 2 mL of KI solution and mixvigorously for 30 6 1 s. Set the flask aside to stand for 5 min6 3s.9.3 At the end of the reaction period, add 100 mL of waterand stop the g

42、as flow. Add 5 mL of starch solution. Titrate with0.005N Na2S2O3solution to the disappearance of the bluecolor.9.4 Titrate a reagent blank just prior to each set of unknowndeterminations, following the same procedure as described in9.1-9.3. (See Note 3.)NOTE 3This end point is of the returning type.

43、 The end point intendedin this method is the disappearance of the blue color for 30 s or longer. Ifthere is no blue color upon the addition of the starch solution, there is nodetectable hydroperoxide and therefore there is no need to titrate thesolution with Na2S2O3solution.10. Quality Control10.1 C

44、onfirm the performance of the test procedure byanalyzing a known hydroperoxide such ast-butylhydroperoxide or cumyl hydroperoxide.11. Calculation11.1 Calculate the peroxide number as follows:Hydroperoxide number, mg/kg 5 A 2 B!N 31000 38#/S (1)where:X = measured hydroperoxide number,A = millilitres

45、of Na2S2O3solution required for titration ofthe sample,B = millilitres of Na2S2O3solution required for titration ofthe blank,N = normality of the Na2S2O3solution,8 = milliequivalent of hydroperoxide number, andS = grams of sample used, accurate to 0.001 g.12. Report12.1 Report the result calculated

46、in 11.1 to three (3) signifi-cant figures.12.2 If there is no detectable hydroperoxide (see Note 3),report “None Detected.”13. Precision and Bias613.1 PrecisionThe precision of this method was deter-mined from an interlaboratory study (ILS). The study con-tained thirteen (13) fuel samples which were

47、 tested in nine (9)laboratories in duplicate. The fuel types in the study were:regular and premium gasoline, ultra low sulfur diesel, Jet A,and isooctane blank. A biodiesel fuel was also included in thestudy but was not used in calculating the precision statementbecause of the variabilities between

48、laboratories.13.1.1 RepeatabilityThe difference between two succes-sive test results, obtained by the same operator with the sameapparatus under constant operating conditions on identical testmaterial would, in the long run, in the normal and correctoperation of the test method, exceed the following

49、 values onlyin one case in twenty:Repeatability 5 0.2829*X10.0001! 0.6596 mg/kg (2)where:X = measured hydroperoxide number in Eq 1.13.1.2 ReproducibilityThe difference between two singleand independent results obtained by different operators work-ing in different laboratories on identical test material would, in6Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR:D02-1630.D3703 07 (2012)3the long run, in the normal and correct operation of the testmethod, exceed the following values