ASTM D7500-15(2019)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D7500 − 15 (Reapproved 2019)
Standard Test Method for
Determination of Boiling Range Distribution of Distillates
and Lubricating Base Oils—in Boiling Range from 100 °C to
735 °C by Gas Chromatography
This standard is issued under the fixed designation D7500; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 1.6 This international standard was developed in accor-
dance with internationally recognized principles on standard-
1.1 This test method covers the determination of the boiling
ization established in the Decision on Principles for the
range distribution of petroleum products by capillary gas
Development of International Standards, Guides and Recom-
chromatography using flame ionization detection. This stan-
mendations issued by the World Trade Organization Technical
dard test method has been developed through the harmoniza-
Barriers to Trade (TBT) Committee.
tion of two test methods, Test Method D6352 and IP 480. As
both of these methods cover the same scope and include very
2. Referenced Documents
similar operating conditions, it was agreed that a single
2.1 ASTM Standards:
standard method would benefit the global simulated distillation
D86 Test Method for Distillation of Petroleum Products and
community.
Liquid Fuels at Atmospheric Pressure
1.2 This test method is not applicable for the analysis of
D1160 Test Method for Distillation of Petroleum Products at
petroleum or petroleum products containing low molecular
Reduced Pressure
weight components (for example naphthas, reformates,
D2887 Test Method for Boiling Range Distribution of Pe-
gasolines, diesel). Components containing hetero atoms (for
troleum Fractions by Gas Chromatography
example alcohols, ethers, acids, or esters) or residue are not to
D5307 Test Method for Determination of Boiling Range
be analyzed by this test method. See Test Methods D7096,
Distribution of Crude Petroleum by Gas Chromatography
D2887,or D7213 for possible applicability to analysis of these 3
(Withdrawn 2011)
types of materials.This method is also not suitable for samples
D6352 Test Method for Boiling Range Distribution of Pe-
that will not elute completely from the gas chromatographic
troleum Distillates in Boiling Range from 174 °C to
column, leaving residues. For such samples as crude oils and
700 °C by Gas Chromatography
residues, see Test Methods D5307 and D7169.
D7096 Test Method for Determination of the Boiling Range
1.3 This test method is applicable to distillates with initial
Distribution of Gasoline by Wide-Bore Capillary Gas
boiling points above 100 ºC and final boiling points below
Chromatography
735 ºC (carbon 110); for example, distillates (IBP > 100 °C), D7169 Test Method for Boiling Point Distribution of
base oils and lubricating base stocks.
Samples with Residues Such as Crude Oils and Atmo-
spheric and Vacuum Residues by High Temperature Gas
1.4 The values stated in SI units are to be regarded as
Chromatography
standard. No other units of measurement are included in this
D7213 Test Method for Boiling Range Distribution of Pe-
standard.
troleum Distillates in the Boiling Range from 100 °C to
1.5 This standard does not purport to address all of the
615 °C by Gas Chromatography
safety concerns, if any, associated with its use. It is the
E355 Practice for Gas ChromatographyTerms and Relation-
responsibility of the user of this standard to establish appro-
ships
priate safety, health, and environmental practices and deter-
E594 Practice for Testing Flame Ionization Detectors Used
mine the applicability of regulatory limitations prior to use.
in Gas or Supercritical Fluid Chromatography
1 2
This test method is under the jurisdiction of ASTM Committee D02 on For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Subcommittee D02.04.0H on Chromatographic Distribution Methods. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved Dec. 1, 2019. Published December 2019. Originally the ASTM website.
approved in 2008. Last previous edition approved in 2015 as D7500 – 15. DOI: The last approved version of this historical standard is referenced on
10.1520/D7500-15R19. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7500 − 15 (2019)
E1510 Practice for Installing Fused Silica Open Tubular 4. Summary of Test Method
Capillary Columns in Gas Chromatographs
4.1 The boiling range distribution determination by distilla-
2.2 ISO Standard:
tion is simulated by the use of gas chromatography. A
ISO 3170 Petroleum Liquids Manual Sampling
non-polar open tubular (capillary) gas chromatographic col-
umnisusedtoelutethehydrocarboncomponentsofthesample
3. Terminology
in order of increasing boiling point.
3.1 Definitions—This test method makes reference to many
4.2 A sample aliquot is diluted with a viscosity reducing
common gas chromatographic procedures, terms, and relation- solvent and introduced into the chromatographic system.
ships. For definitions of these terms used in this test method, Sample vaporization is provided by separate heating of the
refer to Practices E355, E594, and E1510. point of injection or in conjunction with column oven heating.
3.2 Definitions of Terms Specific to This Standard:
4.3 The column oven temperature is raised at a specified
3.2.1 areaslice,n—thearearesultingfromtheintegrationof linear rate to affect separation of the hydrocarbon components
the chromatographic detector signal within a specified reten- in order of increasing boiling point. The elution of sample
tiontimeinterval.Inareaslicemode(see6.4.1),peakdetection components is quantitatively determined using a flame ioniza-
parameters are bypassed and the detector signal integral is tion detector. The detector signal is recorded as area slices for
recorded as area slices of consecutive, fixed duration time consecutive retention time intervals during the analysis.
intervals.
4.4 Retentiontimesofknownnormalparaffinhydrocarbons,
3.2.2 corrected area slice, n—an area slice corrected for spanning the scope of the test method, are determined and
baseline offset by subtraction of the exactly corresponding area
correlated to their boiling point temperatures. The normalized
slice in a previously recorded blank (non-sample) analysis. cumulative corrected sample areas for each consecutive re-
corded time interval are used to calculate the boiling range
3.2.3 cumulativecorrectedarea,n—theaccumulatedsumof
distribution. The boiling point temperature at each reported
correctedareaslicesfromthebeginningoftheanalysisthrough
percent off increment is calculated from the retention time
a given retention time, ignoring any non-sample area (for
calibration.
example, solvent).
3.2.4 final boiling point (FBP), n—the temperature (corre-
5. Significance and Use
spondingtotheretentiontime)atwhichacumulativecorrected
5.1 The boiling range distribution of medium and heavy
area count equal to 99.5 % of the total sample area under the
petroleum distillate fractions provides an insight into the
chromatogram is obtained.
composition of feed stocks and products related to petroleum
3.2.5 initial boiling point (IBP), n—the temperature (corre-
refining processes (for example, hydrocracking, hydrotreating,
spondingtotheretentiontime)atwhichacumulativecorrected
visbreaking, or deasphalting). The gas chromatographic simu-
area count equal to 0.5 % of the total sample area under the
lationofthisdeterminationcanbeusedtoreplaceconventional
chromatogram is obtained.
distillation methods for control of refining operations.This test
method can be used for product specification testing with the
3.2.6 slice rate, n—the frequency used in sampling (analog)
mutual agreement of interested parties.
the chromatographic detector signal during an analysis. The
slice rate is expressed in Hz (for example integrations or slices
5.2 This test method extends the scope of boiling range
per second).
determination by gas chromatography to include distillates
3.2.7 slice time, n—the inverse function of the acquisition (IBP > 100 °C)andheavypetroleumdistillatefractionsbeyond
rate. It is the time duration of each sampling pulse usually the scope of Test Method D2887 (538 °C).
expressed in seconds. The slice time is the time at the end of
5.3 Boiling range distributions obtained by this test method
each contiguous area slice.
havenotbeenanalyzedforcorrelationtothoseobtainedbylow
3.2.8 total sample area, n—the cumulative corrected area,
efficiencydistillation,suchaswithTestMethodD86orD1160.
from the initial area point to the final area point, where the This test method does not claim agreement between these
chromatographic signal has returned to baseline after complete
physical distillations and simulated distillation. Efforts to
sample elution. resolve this question will continue. When successful resolu-
tions of the questions are determined, this test method will be
3.3 Abbreviations—Acommon abbreviation of hydrocarbon
revised accordingly.
compounds is to designate the number of carbon atoms in the
compound. A prefix is used to indicate the carbon chain form,
6. Apparatus
while a subscripted suffix denotes the number of carbon atoms
(for example n-C for normal-decane, i-C for iso- 6.1 Chromatograph—Thegaschromatographicsystemused
10 14
tetradecane).
shall have the following performance characteristics:
6.1.1 Carrier Gas Flow Control—The chromatograph shall
beequippedwithcarriergaspressureorflowcontrolcapableof
maintaining constant carrier gas flow to 61 % throughout the
Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,
4th Floor, New York, NY 10036, http://www.ansi.org. column temperature program cycle.
D7500 − 15 (2019)
TABLE 2 Typical Operating Conditions for Gas Chromatograph
6.1.2 Column Oven—Capable of sustained and linear pro-
grammed temperature operation from near ambient (for Column length, m 5
Column internal diameter, mm 0.53
example, 30 °C to 35 °C) up to 430 °C.
Column material Metal
6.1.3 Column Temperature Programmer—The chromato-
Stationary phase type methyl silicone
graph shall be capable of linear programmed temperature Film thickness, µm 0.09 to 0.17
Initial column temperature, °C 35
operation up to 430 °C at selectable linear rates up to
Initial hold time, min 0
10 °C⁄min. The programming rate shall be sufficiently repro-
Final column temperature, °C 430
Final hold time, min 10
ducible to obtain the retention time repeatability of 0.1 min
Program rate, °C/min 10
(6 s) for each component in the calibration mixture described
Injector initial temperature, °C 100
in 7.5.
Injector final temperature, °C 430
6.1.4 Detector—This test method requires the use of a flame Injector program rate, °C/min 15
Detector temperature, °C 450
ionizationdetector(FID).Thedetectorshallmeetorexceedthe
A
Make-up gas flow, He or N2, mL/min 20
A
following specifications in accordance with Practice E594.
Hydrogen Flow, mL/min 45
A
Air Flow, mL/min 450
Check the detector according the instrument manufacturers
Carrier gas He
instructions.
Carrier gas flow rate, constant flow, mL/ 19
6.1.4.1 Operating Temperature—100 °C to 430 °C.
min
A,B
Sample size, µL 1.0
6.1.4.2 Connection of the column to the detector shall be
Sample concentration, % (m/m) 2
such that no temperature below the column temperature exists
Injector PTV or COC
between the column and the detector. Refer to Practice E1510
A
Consult with the manufacturer’s operations manual.
for proper installation and conditioning of the capillary col-
B
Monitor skewness when varying the injection volume.
umn.
6.1.5 Sample Inlet System—Any sample inlet system ca-
pable of meeting the performance specification in Annex A3
of increasing boiling point and meet the column performance
and execute the conditions of Table 2. Programmable tempera-
requirements of A3.2.1. The column shall provide a resolution
ture vaporization (PTV) and cool on-column (COC) injection
not less than 2 and not higher than 4 using the test method
systems have been used successfully.
operating conditions in Table 2.
6.2 Microsyringe—A microsyringe with a 23-gauge or
6.4 Data Acquisition System:
smaller stainless steel needle is used for on-column sample
6.4.1 Integrator/Computer System—Means shall be pro-
introduction. Syringes of 0.1 µL to 10 µL capacity are avail-
vided for determining the accumulated area under the chro-
able.
matogram. This can be done by means of an electronic
6.2.1 Automatic syringe injection is recommended to
integratororcomputer-basedchromatographydatasystem.The
achieve best precision.
integrator/computer system shall have normal chromato-
6.3 Column—This test method is limited to the use of
graphic software for measuring the retention time and areas of
non-polar wall coated open tubular (WCOT) columns of high
eluting peaks (peak processing mode). In addition, the system
thermal stability. Fused silica (aluminum coated) and stainless
shall be capable of converting the continuously integrated
steelcolumnswith0.53 mmto0.75 mminternaldiameterhave
detector signal into area slices of fixed duration (slice mode).
been successfully used. Cross-linked or bonded 100 %
These contiguous area slices, collected for the entire analysis,
dimethyl-polysiloxane stationary phases with film thickness of
are stored for later processing.Asimilar collection of contigu-
0.09 µm to 0.17 µm have been used. The column length and
ousslicesisalsocollectedfortheblankrun.Itisnecessarythat
liquid phase film thickness shall allow the elution of C n-
110 the number of slices collected for sample and blank analysis
paraffin (BP = 735 °C). The column and conditions shall
are the same. The electronic range of the integrator/computer
provide separation of typical petroleum hydrocarbons in order
(for example 1 V, 10 V) shall be operated within the linear
range of the detector/electrometer system used.
A
TABLE 1 Reference Material 5010 NOTE 1—Some gas chromatographs have an algorithm built into their
operating software that allows a mathematical model of the baseline
% Dist.
°C °F r, °C R, °C r, °F R, °F
profile to be stored in memory. This profile is automatically subtracted
m/m
from the detector signal on subsequent sample runs to compensate for the
IBP 421 789 3 9 5 16
column bleed. Some integration systems also store and automatically
5 476 888 2448
10 491 916 2437 subtract a blank analysis from subsequent analytical determinations.
20 510 950 2539
30 524 975 2539
7. Reagents and Materials
40 536 998 2539
7.1 Liquid Stationary Phase—A methyl silicone stationary
50 548 1018 2539
60 559 1039 2539
phase for the column.
70 572 1061 2539
80 585 1085 2539
7.2 Carrier Gases—Helium, of at least 99.999 % (v/v)
90 602 1116 2539
purity. Any oxygen present is removed by a chemical resin
95 617 1142 2539
filter. (Warning—Follow the safety instructions from the filter
FBP 661 1223 9 17 16 31
A supplier.) Total impurities not to exceed 10 mL/m . Helium or
Values obtained from including Reference Oil 5010 in the ILS sample set.
Nitrogen (99.999 %) can also be used as detector makeup gas.
D7500 − 15 (2019)
NOTE 2—Commercially available alkane standards are suitable for
The use of alternative carrier gases hydrogen and nitrogen is
column performance checks.
described in Appendix X1.
NOTE 3—Calibration mixtures are commercially available.
7.3 Hydrogen—99.999 % Grade suitable for flame ioniza-
7.9 Reference Oil 5010—A reference sample that has been
tion detectors. Total impurities not to exceed 10 mL/m .
analyzed by laboratories participating in the test method
7.4 Compressed Air—Regulated for flame ionization detec-
cooperative study. Consensus values for the boiling range
tors. Total impurities not to exceed 10 mL/m .
distribution of this sample are given Table 1.
NOTE 4—The 5010 reference oil is available commercially.
7.5 Alkanes—Normal alkanes of at least 98 % (m/m) purity
from C to C ,C ,C ,C ,C ,C ,C ,C , and C , are 7.10 Cyclohexane (C H )—(99+ % pure) if necessary, use
5 10 12 14 16 18 20 24 26 28 6 12
to be used with Polywax 655 or 1000. A solution of these in place of CS for the preparation of the calibration mixture.
alkanes is prepared by adding 500 mg of each alkane into a
7.11 A Gravimetric blend consisting of 2 distillation frac-
20 mL vial. Additionally n-tetracontane (C ) can also be
tions is used for system performance check (see A3.3).
added to for ease of carbon counting. This solution is used to
spike the Polywax solution.
8. Sampling and Sample Preparation
7.6 Polywax 655 or 1000.
8.1 Unless otherwise specified, obtain the laboratory
7.7 Carbon Disulfide—Purity 99.7 % (v/v) minimum.
samples by the procedures specified in ISO 3170 and place in
(Warning—Extremely flammable and toxic by inhalation.)
glass or metal containers. Do not use plastic containers for
sample storage to avoid contamination of the sample because
7.8 Calibration Mix—A suitable calibration mixture can be
of possible leaching of the plasticizer.
obtained by dissolving a hydrogenated polyethylene wax (for
5 5
example,Polywax655 orPolywax1000 )inavolatilesolvent
8.2 Sample Preparation—Sample aliquots are introduced
(for example, CS or cyclohexane). Solutions of 1 part Poly-
into the gas chromatograph as solutions in a suitable solvent
wax to 200 parts solvent can be prepared. Lower boiling point
(for example, CS ).
paraffins will have to be added to as specified in 7.5. Fig. 5
8.3 Place approximately 0.1 g to1gofthe sample aliquot
illustrates a typical calibration mixture chromatogram. The
into a screw-capped or crimp-cap vial.
calibration mix is used to determine the column resolution,
8.4 Dilute the sample aliquot to approximately 1 % to 3 %
skewness of components, and retention time versus boiling
by weight with the solvent, depending on the boiling point
point calibration curve. Add 10 µL of the mixture of alkanes
distribution.
prepared in 7.5.
8.5 Seal (cap) the vial, and mix the contents thoroughly to
provide a homogeneous mixture. Warm the vial if necessary
PolywaxisaregisteredtrademarkofBakerPetrolite,12645WestAirportBlvd.,
initially to affect complete solution of the sample. Inspect the
Sugar Land, TX 77478.
FIG. 1 Typical Sample Chromatogram which has a FBP of 700 ºC
D7500 − 15 (2019)
FIG. 2 Typical Calibration Curve of Retention Time versus Boiling Point
sample to ensure it is in stable solution at room temperature 9.6 Inspect and clean the jet periodically to avoid deposits
prior to injection. If necessary, prepare a more dilute solution. that form on the jet from combustion of decomposition
products from the column liquid stationary phase. These
9. Preparation of Apparatus
deposits will affect the characteristics of the detector response.
NOTE 6—The following parameters are affected by deposits on the jet:
9.1 Gas Chromatograph Setup—Set up and operate the gas
increase in inlet pressure, FID difficulty in lighting, increase in the CS
chromatograph in accordance with the manufacturer’s instruc-
response, and off-specification reference oil.To clean the jet, place it in an
tions.
ultrasonic cleaner with a suitable solvent and use a cleaning wire if
NOTE 5—Typical operating conditions are shown in Table 2.
necessary to remove column deposits.
9.2 Anewcolumnwillrequireconditioningattheuppertest 9.7 Check the system performance requirements at installa-
method operating temperature to reduce or eliminate signifi-
tion and at the intervals given and by the procedures specified
cant liquid phase bleed so that a stable and repeatable chro-
in Annex A3 with regards to frequency of calibration, check
matographic baseline can be generated. Disconnecting the
column resolution, peak skewness and verify the detector
column will require conditioning prior to calibration and
response with the gravimetric blend.
analysis.
10. Calibration
9.3 The inlet liner (PTV) and or the initial section of the
10.1 The first run of the day shall be a clean up run and not
column (COC and PTV) shall be periodically inspected and
a usable blank because of the possible elution of extraneous
replaced in order to remove extraneous deposit or sample
components that have concentrated in the inlet while the
residue.
instrument is idle. However, a retention time calibration mix
9.4 Perform a blank analysis after a new septum is installed
(7.8) can be used as first injection.
to ensure that no extraneous peaks are produced by the septum.
10.2 Run the calibration mixture (7.8) and confirm the
The blank analysis shall be carried out whenever the column is
elution of C within the oven temperature program.
disconnected from carrier flow.
NOTE 7—When C does not elute within the temperature program, it
is recommended to shorten the column. See manufacturer’s instructions.
9.5 Ensure that the system’s return to baseline is achieved
near the end of the run and that the baseline shows no drift at 10.3 Ensure the injection volume (or sample concentration)
the final isothermal oven temperature. chosen does not allow any peak to exceed the linear range of
D7500 − 15 (2019)
FIG. 3 Peak Skewness for Calibration Mix Peak C
the detector or overload the column.The skewness of all peaks 10.6 If the consensus values as shown in Table 1 are not
shall be maintained between 0.8 to 1.8. Values greater than 1.8 met, check that all hardware is operating properly and all
indicatethesampleistooconcentratedandaskewlessthan0.8 instrument settings are as recommended by the manufacturer.
indicate severe tailing due to an old column or dirty liner or a Rerun the retention boiling point calibration as described in
poorly focused sample. As a guide, 0.2 µL to 1.0 µL of the 10.3.
calibration mixture (7.8) has been found to be suitable for
11. Sample Analyses Procedure
columns with a film thickness ranging from 0.09 µm to
0.17 µm or less. (See A3.4.)
11.1 Run a solvent (blank) baseline analysis before the first
sample analysis and then after every five samples.
10.4 Record the retention time of each component and plot
theretentiontimeversustheatmosphericboilingpointforeach
11.2 Inspect the baseline at the end of the run for each
component using the boiling points from Table 4. Typical
solvent (blank) injected to ensure that it is constant and stable
results of the calibration are shown in Table 5 and Fig. 2.
and is void of extraneous peaks.
NOTE 9—The identification of a constant baseline at the end of the run
10.5 Inject the Reference Oil 5010 (7.9) using the specified
is critical to the analysis. Constant attention should be given to all factors
procedure (Section 11). Visually inspect the chromatogram.
that influence baseline stability, for example, column substrate bleed,
Using the data system, load the chromatogram (Fig. 6)ofthe
septum bleed, and detector temperature control, constancy of carrier gas
reference oil 5010 and overlay the blank baseline. Enlarge the
flow, leaks, and instrument drift.
section of the chromatogram at the end of sample elution and
11.3 Prepare a Sequence analysis listing all samples and
compare the relative magnitudes of the sample and blank
blank to be injected as described in 11.1.
baselinewiththeexamplesshowninFig.7.Ensurethattheend
NOTE10—Asequenceisaseriesofanalysis.Thelengthofthesequence
of the run merges with the sample chromatogram as shown in
depends on the system stability.
Fig. 7. Calculate the boiling range distribution of the reference
11.4 Cool the column and inlet to the starting temperature
material by the procedures specified in AnnexA1 and compare
and inject the selected sample volume.
this with the consensus values for the reference material used
11.5 Immediately start programming the column tempera-
as listed in Table 1.
ture and the temperature of the PTV or COC inlet.
NOTE 8—Fig. 6 shows a typical chromatogram of the 5010 reference
11.6 Visually inspect the chromatogram. Using the data
oil. Table 6 shows typical boiling point values obtained for the reference
oil. system, load each sample chromatogram overlay the nearest
D7500 − 15 (2019)
FIG. 4 Typical Chromatogram of Gravimetric Blend
blank baseline obtained after the sample as listed in the 11.6.4 The end of the sample is determined by the software
Sequence. Enlarge the section of the chromatogram at the end as given in A1.5.
of sample elution and compare the relative magnitudes of the
12. Calculation
sample and blank baseline with the examples shown in Fig. 7.
Insure that the end of the run merges with the sample 12.1 The following calculations are performed. This section
chromatogramasshowninFig.7.Ifthesamplebaselinehasan is intended as guide for understanding sequence of the calcu-
abrupt break and does not join the blank baseline, it is possible lations outlined in the Annex A1. The detailed steps are given
that the sample has not eluted completely from thee column in Annex A1.
and the sample is considered outside of the scope of this 12.1.1 Zero the sample signal after performing average and
method. standard deviation of slices.
11.6.1 Identify the start of the area of interest by selecting a 12.1.2 Zero the blank signal after performing average and
point on the baseline where the blank and the sample baselines standard deviation of slices.
are merged. This is taken before the start of the sample and 12.1.3 Subtract blank from sample. Set negative slices to
after the end of the solvent (Fig. 8). zero.
11.6.2 Identify the end of the area of interest by selecting a 12.1.4 Calculate total chromatogram area.
point on the baseline where the blank and the sample baselines 12.1.5 Determine start of sample elution time.
are merged. This is taken after the end of the sample and at or 12.1.6 Determine the end of sample elution time.
before the end of run (Fig. 8). 12.1.7 Calculated total corrected sample area.
11.6.3 The start of the sample is determined by the software 12.1.8 Normalize to area percent.
as given in A1.4.
12.1.9 Find retention
...