1、Designation: D5501 121Standard 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 oforiginal adopt
2、ion 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.1NOTEEditorial corrections were made to 7.4.3 and 7.5 in July 2013.1. Scope*1.1 This
3、test method covers the determination of the ethanolcontent 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 mass% to 100 mass%and methanol is determined
4、from 0.01 mass% to 0.6 mass%.Equations used to convert these individual alcohols frommass% to volume% are provided.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 p
5、urport to identify 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 corre
6、ct the concentrations determined bythis method.1.4 This test method is inappropriate for impurities that boilat temperatures higher than 225C 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 thestanda
7、rd. The values 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 deter
8、mine the applica-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
9、 Reagent Titration 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, PetroleumProducts, and LubricantsD4307 Practice for Preparation o
10、f Liquid 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,
11、tertiary-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 Engines
12、D6299 Practice for Applying Statistical Quality Assuranceand Control Charting Techniques to Evaluate AnalyticalMeasurement System Performance1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.04.0L
13、 on Hydrocarbon Analysis.Current edition approved Nov. 1, 2012. Published March 2013. Originallyapproved in 1994. Last previous edition approved in 2009 as D5501 09. DOI:10.1520/D5501-12E01.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at servi
14、ceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.*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
15、 States1D6792 Practice for Quality System in Petroleum Productsand Lubricants Testing LaboratoriesE203 Test Method for Water Using Volumetric Karl FischerTitrationE355 Practice for Gas Chromatography Terms and Relation-shipsE594 Practice for Testing Flame Ionization Detectors Usedin Gas or Supercrit
16、ical Fluid ChromatographyE1064 Test Method for Water in 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 proc
17、edures, terms, and relation-ships. Detailed definitions 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
18、of a component divided by that of anothercomponent.3.2.2.1 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 Discussi
19、onSince the majority of the area beneaththe rider peak 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 f
20、actor3.3.2 RMRFrelative mass response factor4. Summary 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
21、 thecomponents are chromatographically separated in order 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
22、-paring their retention times to the ones identified by 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.
23、 Significance and Use5.1 This test method provides a method of determining thepercentage of ethanol in an ethanol-gasoline fuel blend over therange of 20 to 100 mass% for compliance with fuel specifica-tions and federal or local fuel regulations.5.2 Ethanol content of denatured fuel ethanol for gaso
24、lineblending is required in accordance with 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
25、. A heated flash vaporizing injectordesigned 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. Pr
26、essure and flow control devices shall bedesigned 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 syr
27、inge sampleinjection to the splitting injector. Devices capable of 0.1 to 0.5L 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
28、 analysis.6.3 ColumnThe precision for this 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 thosede
29、scribed in 6.3.1 may be used.6.3.1 Open tubular 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.TABLE 1 Typical Operating ConditionsCo
30、lumn Temperature ProgramColumn length 100 m 150 mInitial temperature 15C 60CInitial hold time 12 min 15 minProgram rate 30C/min 30C/minFinal temperature 250C 250CFinal hold time 19 min 23 minInjectorTemperature 300CSplit ratio 200:1Sample size 0.1 to 0.5 LDetectorType Flame ionizationTemperature 300
31、CFuel gas Hydrogen (30 mL/min)Oxidizing gas Air (300 mL/min)Make-up gas Helium or Nitrogen (30 mL/min)Date rate 20 HzCarrier GasType Helium or HydrogenAAverage linear velocity 2124 cm/s (constant flow)AUse of hydrogen carrier gas requires additional safety considerations.D5501 1212The 150 m column i
32、s recommended due to its higher resolu-tion. Follow Practice 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:6.4.1 Capacity for at least 80 peaks/a
33、nalysis,6.4.2 Normalized 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%-83%ethanol), and mid-leve
34、l ethanol blends (20%-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
35、 are performed 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 instr
36、umental sensitivity and integration parameterssuch that any component of at least 0.002 mass % is detectedand integrated.12.3 Inject 0.1 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 p
37、eakTABLE 2 Recommended Matrix of Calibration Standards Rangingfrom 20 to 99 Mass%Mix 1 Mix 2 Mix 3 Mix 4 Mix 5Methanol, mass% 0.6 0.5 0.3 0.2 0.1Ethanol, mass% 20.0 50.0 75.0 90.0 99.4Heptane, mass% 10.0 10.0 10.0 4.0 0.5Hydrocarbon diluent,Amass%69.4 39.5 14.8 5.8 0.0AHydrocarbon diluent is free of
38、 heptane and any other compounds that wouldinterfere with the calibration. See 7.4.D5501 1216integration 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 calibration factor determined in
39、10.4 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 calibration for unknown
40、s.ARi5 areai3RF(F)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 corresponding calibrati
41、on 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 calibration (single- or
42、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 95-105 mass%. Failure tomeet these limits can indicate a poor calibration and/o
43、rintegration, high water content, or a change in the system sincethe time of calibration.Mass% recovery 5 ARt(5)where:ARt= sum of ARifor all detected peaks.13.2 Determine the normalized relative mass percent of theindividual alcohols by using the following equation:RMi5ARi3100ARt(6)where:RMi= normal
44、ized relative mass% of the individual alcohols,ARi= response corrected peak area of component i, andARt= sum of ARifor all detected peaks.13.3 Obtain the mass% of water in the sample. Test Meth-ods D1364, E203, E1064, or equivalent, may be used.13.4 Determine the mass% of the alcohols of interest by
45、using the following equation:FIG. 4 Sample Chromatogram of Calibration Mixture on 150 m ColumnD5501 1217Mi5RMi3 100 2 mass % water in sample!100(7)where:Mi= mass% of the individual alcohol being determined,andRMi= normalized relative mass% of the individual alcoholfrom Eq 6.13.5 For the volumetric c
46、oncentration of the alcohol, calcu-late as follows:Vi5Mi3DsDi(8)where:NOTE 1The regression is linear with a correlation coefficient greater than 0.995 and the calibration curve passes within 3 mass% ethanol of the origin.FIG. 5 Calibration Linearity Checks are Shown Using Either Axis for Ethanol Con
47、tentTABLE 3 Pertinent Component DataTypical Mass RelativeResponse FactorsADensity at 20C,g/mLRelative Density at15.56CMethanol 3.20 0.791 0.796Ethanol 2.06 0.789 0.794Awhere n-heptane = 1.D5501 1218Vi= volume% of component i,Mi= mass% of component i from Eq 7,Di= density of component i at test tempe
48、rature t as found inTable 2, 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 mass% using Eq 7 or nearest 0.01 volume% usingEq 8 and reference this test method.15. Precision and Bias4
49、15.1 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 by the same operator with the same apparatus4Supporting data (results of the 2011 ILS) have been filed atASTM InternationalHeadquarters and may be obtained by requesting Research Report RR:D02-1749.Contact ASTM Customer Service at serviceastm.org.FIG. 6 Sample Chromatogram of a 20% E
