1、Designation: D5501 12 (Reapproved 2016)Standard Test Method forDetermination of Ethanol and Methanol Content in FuelsContaining Greater than 20% Ethanol by GasChromatography1This standard is issued under the fixed designation D5501; the number immediately following the designation indicates the year
2、 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 test method covers the determination of the ethanol
3、content of hydrocarbon blends containing greater than 20 %ethanol. This method is applicable to denatured fuel ethanol,ethanol fuel blends, and mid-level ethanol blends.1.1.1 Ethanol is determined from 20 % by mass to 100 % bymass and methanol is determined from 0.01 % by mass to0.6 % by mass. Equat
4、ions used to convert these individualalcohols from percent by mass to percent by volume areprovided.NOTE 1Fuels containing less than 20 % ethanol may be quantifiedusing Test Method D5599, and less than 12 % ethanol may be quantifiedusing Test Method D4815.1.2 This test method does not purport to ide
5、ntify all indi-vidual components common to ethanol production or thosecomponents that make up the denaturant or hydrocarbonconstituent of the fuel.1.3 Water cannot be determined by this test method andshall be measured by a procedure such as Test Method D1364and the result used to correct the concen
6、trations determined bythis method.1.4 This test method is inappropriate for impurities that boilat temperatures higher than 225 C or for impurities that causepoor or no response in a flame ionization detector, such aswater.1.5 The values stated in SI units are to be regarded as thestandard. The valu
7、es given in parentheses are provided forinformation purposes only.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 appro-priate safety and health practices and determine the app
8、lica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D1298 Test Method for Density, Relative Density, or APIGravity of Crude Petroleum and Liquid Petroleum Prod-ucts by Hydrometer MethodD1364 Test Method for Water in Volatile Solvents (KarlFischer Reagent Tit
9、ration Method)D4052 Test Method for Density, Relative Density, and APIGravity of Liquids by Digital Density MeterD4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD4175 Terminology Relating to Petroleum Products, LiquidFuels, and LubricantsD4307 Practice for Preparation of Liquid
10、Blends for Use asAnalytical StandardsD4626 Practice for Calculation of Gas ChromatographicResponse FactorsD4806 Specification for Denatured Fuel Ethanol for Blend-ing with Gasolines for Use as Automotive Spark-IgnitionEngine FuelD4815 Test Method for Determination of MTBE, ETBE,TAME, DIPE, tertiary-
11、Amyl Alcohol and C1to C4Alco-hols in Gasoline by Gas ChromatographyD5599 Test Method for Determination of Oxygenates inGasoline by Gas Chromatography and Oxygen SelectiveFlame Ionization DetectionD5798 Specification for Ethanol Fuel Blends for Flexible-Fuel Automotive Spark-Ignition EnginesD6299 Pra
12、ctice for Applying Statistical Quality Assuranceand Control Charting Techniques to Evaluate AnalyticalMeasurement System PerformanceD6792 Practice for Quality System in Petroleum Productsand Lubricants Testing LaboratoriesE203 Test Method for Water Using Volumetric Karl FischerTitration1This test me
13、thod is under the jurisdiction of ASTM Committee D02 onPetroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility ofSubcommittee D02.04.0L on Hydrocarbon Analysis.Current edition approved Oct. 1, 2016. Published November 2016. Originallyapproved in 1994. Last previous edition
14、approved in 2012 as D5501 121. DOI:10.1520/D5501-12R16.2For 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.Copyri
15、ght ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1E355 Practice for Gas Chromatography Terms and Relation-shipsE594 Practice for Testing Flame Ionization Detectors Usedin Gas or Supercritical Fluid ChromatographyE1064 Test Method for Water in
16、 Organic Liquids by Coulo-metric Karl Fischer TitrationE1510 Practice for Installing Fused Silica Open TubularCapillary Columns in Gas Chromatographs3. Terminology3.1 DefinitionsThis test method makes reference to manycommon chromatographic procedures, terms, and relation-ships. Detailed definitions
17、 can be found in TerminologyD4175, and Practices E355 and E594.3.2 Definitions:3.2.1 mass response factor (MRF), nconstant of propor-tionality that converts area to mass percent.3.2.2 relative mass response factor (RMRF), nmass re-sponse factor of a component divided by that of anothercomponent.3.2.
18、2.1 DiscussionIn this test method, the mass responsefactors are relative to that of n-heptane.3.2.3 tangential skimming, nin gas chromatography, inte-gration technique used when a “rider” peak elutes on the tail ofa primary peak.3.2.3.1 DiscussionSince the majority of the area beneaththe rider peak
19、belongs to the primary peak, in tangentialskimming the top of the primary peak tail is used as thebaseline of the rider peak, and the triangulated area beneath therider peak is added to the primary peak.3.3 Abbreviations:3.3.1 MRFmass response factor3.3.2 RMRFrelative mass response factor4. Summary
20、of Test Method4.1 A representative aliquot of the fuel ethanol sample isintroduced into a gas chromatograph equipped with a polydim-ethylsiloxane bonded phase capillary column. Carrier gastransports the vaporized aliquot through the column where thecomponents are chromatographically separated in ord
21、er ofboiling point temperature. Components are sensed by a flameionization detector as they elute from the column. The detectorsignal is processed by an electronic data acquisition system.The ethanol and methanol components are identified by com-paring their retention times to the ones identified by
22、 analyzingstandards under identical conditions. The concentrations of allcomponents are determined in mass percent by normalizationof the peak areas. After correction for water content, resultsmay be reported in mass percent or volume percent.5. Significance and Use5.1 This test method provides a me
23、thod of determining thepercentage of ethanol in an ethanol-gasoline fuel blend over therange of 20 % by mass to 100 % by mass for compliance withfuel specifications and federal or local fuel regulations.5.2 Ethanol content of denatured fuel ethanol for gasolineblending is required in accordance with
24、 Specification D4806.5.3 Ethanol content of ethanol fuel blends for flexible-fuelautomotive spark-ignition engines is required in accordancewith Specification D5798.6. Apparatus6.1 Gas Chromatograph, capable of operating at the condi-tions listed in Table 1. A heated flash vaporizing injectordesigne
25、d to provide a linear sample split injection (forexample, 200:1) is required for proper sample introduction.Carrier gas controls shall be of adequate precision to providereproducible column flows and split ratios in order to maintainanalytical integrity. Pressure and flow control devices shall bedes
26、igned to attain the linear velocity required in the columnused. A hydrogen flame ionization detector with associated gascontrols and electronics, designed for optimum response withopen tubular columns, is required.6.2 Sample IntroductionAutomatic liquid syringe sampleinjection to the splitting injec
27、tor. Devices capable of 0.1 L to0.5 L injections are suitable.NOTE 2Inadequate splitter, poor injection technique, and overloadingthe column can result in poor resolution. Avoid overloading, particularlyof the ethanol peak, and eliminate this condition during analysis.6.3 ColumnThe precision for thi
28、s test method was devel-oped utilizing a fused silica open tubular column with non-polar polydimethylsiloxane bonded (cross-linked) phase inter-nal coating. Any column with equivalent or betterchromatographic efficiency, resolution, and selectivity to thosedescribed in 6.3.1 may be used.6.3.1 Open t
29、ubular column with a non-polar polydimethyl-siloxane bonded (cross-linked) phase internal coating, either150 m by 0.25 mm with a 1.0 m film thickness, or 100 m by0.25 mm with a 0.5 film thickness have been found suitable.The 150 m column is recommended due to its higher resolu-tion. Follow Practice
30、E1510 for column installation.6.4 Electronic Data Acquisition SystemAny data acquisi-tion and integration device used for quantification of theseanalyses must meet or exceed these minimum requirements:TABLE 1 Typical Operating ConditionsColumn Temperature ProgramColumn length 100 m 150 mInitial temp
31、erature 15 C 60 CInitial hold time 12 min 15 minProgram rate 30 C min 30 C minFinal temperature 250 C 250 CFinal hold time 19 min 23 minInjectorTemperature 300 CSplit ratio 200:1Sample size 0.1 L to 0.5 LDetectorType Flame ionizationTemperature 300 CFuel gas Hydrogen (30 mL min)Oxidizing gas Air (30
32、0 mL/min)Make-up gas Helium or Nitrogen (30 mL/min)Date rate 20 HzCarrier GasType Helium or HydrogenAAverage linear velocity 21 cm s to 24 cm/s (constant flow)AUse of hydrogen carrier gas requires additional safety considerations.D5501 12 (2016)26.4.1 Capacity for at least 80 peaks/analysis,6.4.2 No
33、rmalized percent calculation based on peak areaand using response factors,6.4.3 Identification of individual components based on re-tention time,6.4.4 Noise and spike rejection capability,6.4.5 Sampling rate for narrow (95 % Ethanol), ethanol fuel blends (51 % to83 % ethanol), and mid-level ethanol
34、blends (20 % to 51 %ethanol).11.1.2 Prepare standard(s) in sufficient volume to allow fora minimum of 30 quality control measurements to be made onone batch of material. Properly package and store the qualitycontrol samples to ensure that all analyses of quality controlsamples from a given lot are p
35、erformed on essentially identicalmaterial. Use of the Q-procedure in Practice D6299 is recom-mended when switching between batches of control sample.12. Gas Chromatographic Analysis Procedure12.1 Set the instrument operating variables. See Table 1 fortypical operating conditions.12.2 Set instrumenta
36、l sensitivity and integration parameterssuch that any component of at least 0.002 mass % is detectedand integrated.12.3 Inject 0.1 L to 0.5 L of sample into the injection portand start the analysis. Obtain a chromatogram and verify theintegration (see 9.5) and peak identification. Generate the peakT
37、ABLE 2 Recommended Matrix of Calibration Standards Rangingfrom 20 % to 99 % by MassMix 1 Mix 2 Mix 3 Mix 4 Mix 5Methanol, % by mass 0.6 0.5 0.3 0.2 0.1Ethanol, % by mass 20.0 50.0 75.0 90.0 99.4Heptane, % by mass 10.0 10.0 10.0 4.0 0.5Hydrocarbon diluent,A% by mass69.4 39.5 14.8 5.8 0.0AHydrocarbon
38、diluent is free of heptane and any other compounds that wouldinterfere with the calibration. See 7.4.D5501 12 (2016)6integration or system report. Quantify results using calcula-tions in Section 13. Sample chromatograms are shown in Fig.6 and Fig. 7.13. Calculation13.1 Apply the appropriate calibrat
39、ion factor determined in10.4 to each peak area.13.1.1 For single point or relative mass response factorcalibration, calculate the response corrected peak area (ARi)ofeach component according to Eq 4. Repeat for each peak, usingresponse factors determined for individual compounds andusing the heptane
40、 calibration for unknowns.ARi5 areai3RFF!i(4)where:ARi= response corrected peak area (i),areai= peak area of component (i), andRF(F)i= mass response factor (MRF) or relative mass re-sponse factor (RMRF) of component (i) relative ton-C7.13.1.2 For multi-point calibration, input the peak area intothe
41、corresponding calibration equation determined in 10.4.1.2.Solve for the raw mass percent of component i, which isequivalent to ARi. Repeat for each peak, using calibrationequations determined for individual compounds and using theheptane calibration equation for unknowns.13.1.3 When using absolute c
42、alibration (single- or multi-point) it is possible to monitor mass percent recovery. Calcu-late the raw mass percent recovery of the sample according toEq 5. When properly calibrated, a fully eluting sample isexpected to give a raw recovery of 95 % to 105 % by mass.Failure to meet these limits can i
43、ndicate a poor calibrationand/or integration, high water content, or a change in thesystem since the time of calibration.Mass% recovery 5 ARt(5)where:ARt= sum of ARifor all detected peaks.FIG. 4 Sample Chromatogram of Calibration Mixture on 150 m ColumnD5501 12 (2016)713.2 Determine the normalized r
44、elative mass percent of theindividual alcohols by using the following equation:RMi5ARi3100ARt(6)where:RMi= normalized relative percent by mass of the individualalcohols,ARi= response corrected peak area of component i, andARt= sum of ARifor all detected peaks.13.3 Obtain the percent by mass of water
45、 in the sample. TestMethods D1364, E203, E1064, or equivalent, may be used.13.4 Determine the percent by mass of the alcohols ofinterest by using the following equation:Mi5RMi3 100 2 mass % water in sample!100(7)where:Mi= percent by mass of the individual alcohol beingdetermined, andRMi= normalized
46、relative percent by mass of the individualalcohol from Eq 6.NOTE 1The regression is linear with a correlation coefficient greater than 0.995 and the calibration curve passes within 3 % by mass ethanol of theorigin.FIG. 5 Calibration Linearity Checks are Shown Using Either Axis for Ethanol ContentTAB
47、LE 3 Pertinent Component DataTypical Mass RelativeResponse FactorsADensity at 20 C,g/mLRelative Density at15.56 CMethanol 3.20 0.791 0.796Ethanol 2.06 0.789 0.794Awhere n-heptane = 1.D5501 12 (2016)813.5 For the volumetric concentration of the alcohol, calcu-late as follows:Vi5Mi3 DsDi(8)FIG. 6 Samp
48、le Chromatogram of a 20 % Ethanol Blend (E20) on 150 m ColumnFIG. 7 Sample Chromatogram (Expanded View) of 20 % Ethanol Blend on 100 m ColumnD5501 12 (2016)9where:Vi= % by volume of component i,Mi= % by mass of component i from Eq 7,Di= density of component i at test temperature t as found inTable 3
49、, andDs= sample density at test temperature t as determined byTest Method D1298 or D4052.14. Report14.1 Report the purity of the individual alcohols to thenearest 0.01 % by mass using Eq 7 or nearest 0.01 % byvolume using Eq 8 and reference this test method.15. Precision and Bias415.1 PrecisionThe precision of this test method as deter-mined by the statistical examination of the interlaboratory gaschromatographic test results of denatured fuel ethanol is asfollows:15.1.1 RepeatabilityThe difference between successiveresults obtained b
