1、Designation: D7798 15Standard Test Method forBoiling Range Distribution of Petroleum Distillates withFinal Boiling Points up to 538 C by Ultra Fast GasChromatography (UF GC)1This standard is issued under the fixed designation D7798; 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. Scope*1.1 This test method covers the determination of the boilin
3、grange distribution of petroleum products and biodieselformulations, B5, B10, and B20. It is applicable to petroleumdistillates having a final boiling point not greater than 538 Cor lower at atmospheric pressure as measured by this testmethod.The difference between the initial boiling point and thef
4、inal boiling point shall be greater than 55 C.1.2 The test method is not applicable for analysis ofpetroleum distillates containing low molecular weight compo-nents (for example naphthas, reformates, gasolines, full rangecrude oils). Materials containing heterogeneous mixtures (forexample, alcohols,
5、 ethers, acids or esters, except biodiesels) orresidue are not to be analyzed by this test method. See TestMethods D3710, D7096, D6352,orD7169.1.3 This test method uses the principles of simulated distil-lation methodology. This test method uses gas chromato-graphic components that allow the entire
6、analysis from sampleto sample to occur in 5 min or less. In these instruments thecolumn is heated directly at rates 10 to 15 times that of aconventional gas chromatograph and thus the analysis time isreduced from sample to sample.1.4 The values stated in SI units are to be regarded asstandard. No ot
7、her units of measurement are included in thisstandard.1.4.1 ExceptionAppendix X1 includes temperatures inFahrenheit for information only.1.5 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 e
8、stablish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D86 Test Method for Distillation of Petroleum Products atAtmospheric PressureD1160 Test Method for Distillation of Petroleum Products a
9、tReduced PressureD2887 Test Method for Boiling Range Distribution of Pe-troleum Fractions by Gas ChromatographyD2892 Test Method for Distillation of Crude Petroleum(15-Theoretical Plate Column)D3710 Test Method for Boiling Range Distribution of Gaso-line and Gasoline Fractions by Gas Chromatography(
10、Withdrawn 2014)3D4626 Practice for Calculation of Gas ChromatographicResponse FactorsD6300 Practice for Determination of Precision and BiasData for Use in Test Methods for Petroleum Products andLubricantsD6352 Test Method for Boiling Range Distribution of Pe-troleum Distillates in Boiling Range from
11、 174 C to700 C by Gas ChromatographyD6708 Practice for Statistical Assessment and Improvementof Expected Agreement Between Two Test Methods thatPurport to Measure the Same Property of a MaterialD7096 Test Method for Determination of the Boiling RangeDistribution of Gasoline by Wide-Bore Capillary Ga
12、sChromatographyD7169 Test Method for Boiling Point Distribution ofSamples with Residues Such as Crude Oils and Atmo-spheric and Vacuum Residues by High Temperature GasChromatographyE355 Practice for Gas Chromatography Terms and Relation-shipsE594 Practice for Testing Flame Ionization Detectors Used1
13、This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility ofSubcommittee D02.04.0H on Chromatographic Distribution Methods.Current edition approved Oct. 1, 2015. Published November 2015. Originallyapproved in
14、2013. Last previous edition approved in 2013 as D7798 13. DOI:10.1520/D7798-15.2For 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 o
15、nthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.*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 States1in Gas or Supercrit
16、ical Fluid ChromatographyE1510 Practice for Installing Fused Silica Open TubularCapillary Columns in Gas Chromatographs3. Terminology3.1 Definitions:3.1.1 This test method makes reference to many commongas chromatographic procedures, terms, and relationships.Detailed definitions of these can be foun
17、d in Practices E355,E594, and E1510.3.1.2 area slice, nin gas chromatography, the area, result-ing from the integration of the chromatographic detectorsignal, within a specified retention time interval.3.1.3 corrected area slice, nin gas chromatography,anarea slice corrected for baseline offset, by
18、subtraction of thecorresponding area slice in a previously recorded blank (non-sample) analysis.3.1.4 cumulative corrected area, nin gaschromatography, the accumulated sum of corrected area slicesfrom the beginning of the analysis through to a given retentiontime, ignoring any non-sample areas (for
19、example, solventpeak area).3.1.5 Final Boiling Point (FBP), nin gaschromatography, the temperature (corresponding to the reten-tion time) at which a cumulative corrected area count equal to99.5 % of the total sample area under the chromatogram isobtained.3.1.6 Initial Boiling Point (IBP), nin gaschr
20、omatography, the temperature (corresponding to the reten-tion time) at which a cumulative corrected area count equal to0.5 % of the total sample area under the chromatogram isobtained.3.1.7 slice rate, nin gas chromatography, the time intervalused to integrate the continuous (analog) chromatographic
21、detector response during an analysis, expressed in Hz.3.1.7.1 Discussionfor example, integrations or slices persecond.3.1.8 slice time, nin gas chromatography, the time dura-tion of the slice, in seconds.The slice time is the time at the endof each contiguous area slice.3.1.9 total sample area, nin
22、gas chromatography, thecumulative corrected area, from the initial area point to thefinal area point.3.2 Abbreviations:3.2.1 Acommon abbreviation of hydrocarbon compounds isto designate the number of carbon atoms in the compound. Aprefix is used to indicate the carbon chain form, while asubscripted
23、suffix denotes the number of carbon atoms (forexample, n-Cl0normal decane; iCl4= iso tetradecane).4. Summary of Test Method4.1 The boiling range distribution of hydrocarbon fractionsobtained by physical distillation is simulated by the use of gaschromatography (GC). The GC column heating is accom-pl
24、ished by supplying heat to the column directly instead of anoven with a consequence that the elution time is considerablyshortened. Thus, cycle times of 5 min or less (heating andcooling) is achieved. A non-polar capillary gas chromato-graphic column is used to separate the hydrocarbon compo-nents o
25、f the sample and cause them to elute in order ofincreasing boiling point.4.2 Depending on the analyzer and column used, a samplealiquot is diluted with a viscosity reducing solvent or intro-duced neat into the chromatographic system. Sample vaporiza-tion is provided by separate heating of the point
26、of injection orin conjunction with column oven heating.4.3 The column temperature is raised at a reproduciblelinear rate to effect separation of the hydrocarbon componentsin order of increasing boiling point. The elution of samplecomponents is quantitatively determined using a flame ioniza-tion dete
27、ctor. The detector signal integral is recorded as areaslices for consecutive retention time intervals during theanalysis.4.4 Retention times of known normal paraffin hydrocarbons,spanning the scope of the test method (C5to C44), aredetermined and correlated to their boiling point temperatures.(Refer
28、 to Table 1.) The normalized cumulative correctedsample areas for each consecutive recorded time interval areused to calculate the boiling range distribution. The boilingpoint temperature at each reported percent off increment iscalculated from the retention time calibration.5. Significance and Use5
29、.1 The boiling range distribution of petroleum distillatefractions provides an insight into the composition of feedstocks and products related to petroleum refining processes. Amajor advantage of the fast analysis time obtained by this testmethod is increasing product through put and reduced labtest
30、ing time by a minimum factor of 3. This gas chromato-graphic determination of boiling range may be used to replaceconventional distillation methods for control of refining opera-tions and for product specification testing with the mutualagreement of interested parties.5.2 Boiling range distributions
31、 obtained by this test methodare essentially equivalent to those obtained by true boilingpoint (TBP) distillation (see Test Method D2892). They are notequivalent to results from low efficiency distillations such asthose obtained with Test Method D86 or D1160.6. Apparatus6.1 ChromatographThe gas chro
32、matographic system usedshall have the following performance characteristics:6.1.1 Column Heating AssemblyCapable of sustaining aprogrammed temperature operation from 40 C up to 400 C.6.1.2 Column Temperature ProgrammerThe columnshould be capable of linear programmed temperature operationup to 400 C
33、at selectable linear rates from a minimum of60 Cmin up to 350 Cmin. The programming rate shall besufficiently reproducible to obtain the retention time repeatabil-ity for the mixture described in 7.6.6.1.3 DetectorThis test method requires a flame ioniza-tion detector (FID). The detector shall meet
34、or exceed thefollowing specifications as detailed in Practice E594. TheD7798 152flame jet should have an orifice of approximately 0.018 in. or0.45 mm or as specified by the manufacturer.6.1.3.1 Operating Temperature approximately 380 C to400 C.6.1.3.2 Sensitivity 0.005 coulombs/ g carbon.6.1.3.3 Min
35、imum Detectability110-12g carbon persecond for n-C13.6.1.3.4 Linear Range 106.6.1.3.5 Connection of the column to the detector shall besuch that no temperature below the column inlet temperatureexists. Refer to E1510 for proper installation and conditioningof the capillary column.6.1.4 Sample Inlet
36、SystemAny sample inlet system ca-pable of operating continuously at a temperature equivalent tothe maximum column temperature employed. Programmedtemperature vaporization (PTV) and programmable cool on-column injection and split injection systems have been usedsuccessfully. Table 2 gives some exampl
37、es of operating con-ditions of commercially available instrumentation. The inletshould be capable to continuously deliver the sample compo-nents in to the column by maintaining the temperature higherthan the column temperature.6.1.5 Carrier Gas Flow ControlThe chromatograph shallbe equipped with car
38、rier gas pressure or flow control capable ofmaintaining constant carrier gas flow control through thecolumn throughout the column temperature program cycle.The flow shall not vary by more than 1 % from the initialtemperature to the end column temperature.6.2 MicrosyringeSyringes of 0.1 L to 5 L capa
39、city aresuitable for this test method. Consult manufacturer for specificdetails on requirements for syringes compatible with autosam-pler and injection technique used.6.2.1 Automatic syringe injection is required to achieve bestprecision.6.3 ColumnThis test method is limited to the use ofnon-polar w
40、all coated open tubular (WCOT) columns of highthermal stability. Fused silica, and stainless steel columns, witha 0.32 mm to 0.18 mm inside diameter have been successfullyused. Cross-linked or bonded 100 % dimethyl-polysiloxanestationary phases with film thickness of 0.1 m to 1.0 m havebeen used. It
41、 is required that the choice of these two variables(column i.d. and phase thickness) allow the elution of C5to C44during the temperature programming phase of the column. Thecolumn and conditions shall provide separation of typicalpetroleum hydrocarbons in order of increasing boiling pointand meet th
42、e column resolution requirements of 8.2.1. Thecolumn shall provide a resolution of at least three (3) using thetest method operating conditions. Table 2 gives some examplesof columns used successfully.6.4 Data Acquisition System:6.4.1 ComputerMeans shall be provided for determiningthe accumulated ar
43、ea under the chromatogram. This can bedone by means of a computer based chromatography datasystem. The computer system shall have normal chromato-graphic software for measuring the retention time and areas ofeluting peaks (peak detection mode). In addition, the systemshall be capable of converting t
44、he continuously integrateddetector signal into area slices of fixed duration (area slicemode). These contiguous area slices, collected for the entireanalysis, are stored for later processing. Gas Chromatographswith analog to digital conversion of the detector signal, shall beoperated within the line
45、ar range of the detector/electrometersystem used. Since the chromatogram is developing in a veryshort time and since the peaks elute at a fast rate, it is necessaryto acquire the signals at 50 Hz to 100 Hz.TABLE 1 Boiling Points of n-ParaffinsA,BCarbonNumberBoilingPoint, CBoilingPoint, F536976 69 15
46、67 98 2098 126 2589 151 30310 174 34511 196 38512 216 42113 235 45614 254 48815 271 51916 287 54817 302 57618 316 60119 330 62620 344 65121 356 67422 369 69523 380 71624 391 73625 402 75526 412 77427 422 79128 431 80829 440 82530 449 84031 458 85632 466 87033 474 88534 481 89835 489 91236 496 92537
47、503 93738 509 94839 516 96140 522 97241 528 98242 534 99343 540 100444 545 1013AAPI Project 44, October 31, 1972 is believed to have provided the original normalparaffin boiling point data that are listed in Table 1. However, over the years someof the data contained in both API Project 44 (Thermodyn
48、amics Research CenterHydrocarbon Project) and Test Method D2887 have changed, and they are nolonger equivalent. Table 1 represents the current normal paraffin boiling pointvalues accepted by Subcommittee D02.04 and found in all test methods under thejurisdiction of Section D02.04.0H.BTest Method D28
49、87 has traditionally used n-paraffin boiling points rounded to thenearest whole degree for calibration. The boiling points listed in Table 1 are correctto the nearest whole number in both degrees Celsius and degrees Fahrenheit.However, if a conversion is made from one unit to the other and then rounded toa whole number, the result will not agree with the table value for a few carbonnumbers. For example, the boiling point of n-heptane is 98.425 C, which iscorrectly rounded to 98 C in the table. However, converting 98.425 C gives209.165 F, w
