ASTM D7500-08

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation:D7500–08
Standard Test Method for
Determination of Boiling Range Distribution of Distillates
and Lubricating Base Oils—in Boiling Range from 100 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 priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
1.1 This test method covers the determination of the boiling
range distribution of petroleum products by capillary gas
2. Referenced Documents
chromatography using flame ionization detection. This stan-
2.1 ASTM Standards:
dard test method has been developed through the harmoniza-
D86 Test Method for Distillation of Petroleum Products at
tion of two test methods, Test Method D6352 and IP 480. As
Atmospheric Pressure
both of these methods cover the same scope and include very
D1160 Test Method for Distillation of Petroleum Products
similar operating conditions, it was agreed that a single
at Reduced Pressure
standard method would benefit the global simulated distillation
D2887 Test Method for Boiling Range Distribution of
community.
Petroleum Fractions by Gas Chromatography
1.2 This test method is not applicable for the analysis of
D5307 Test Method for Determination of Boiling Range
petroleum or petroleum products containing low molecular
Distribution of Crude Petroleum by Gas Chromatography
weight components (for example naphthas, reformates, gaso-
D6352 Test Method for Boiling Range Distribution of
lines, diesel). Components containing hetero atoms (for ex-
Petroleum Distillates in Boiling Range from 174 to 700°C
ample alcohols, ethers, acids, or esters) or residue are not to be
by Gas Chromatography
analyzedbythistestmethod.SeeTestMethodsD7096,D2887,
D7096 TestMethodforDeterminationoftheBoilingRange
orD7213forpossibleapplicabilitytoanalysisofthesetypesof
Distribution of Gasoline by Wide-Bore Capillary Gas
materials.This method is also not suitable for samples that will
Chromatography
not elute completely from the gas chromatographic column,
D7169 Test Method for Boiling Point Distribution of
leaving residues. For such samples as crude oils and residues,
Samples with Residues Such as Crude Oils and Atmo-
see Test Methods D5307 and D7169.
spheric and Vacuum Residues by High Temperature Gas
1.3 This test method is applicable to distillates with initial
Chromatography
boiling points above 100ºC and final boiling points below
D7213 Test Method for Boiling Range Distribution of
735ºC (carbon 110); for example, distillates (IBP > 100°C),
Petroleum Distillates in the Boiling Range from 100 to
base oils and lubricating base stocks.
615°C by Gas Chromatography
1.4 The values stated in SI units are to be regarded as
E355 Practice for Gas Chromatography Terms and Rela-
standard. No other units of measurement are included in this
tionships
standard.
E594 Practice for Testing Flame Ionization Detectors Used
1.5 This standard does not purport to address all of the
in Gas or Supercritical Fluid Chromatography
safety concerns, if any, associated with its use. It is the
E1510 Practice for Installing Fused Silica Open Tubular
responsibility of the user of this standard to establish appro-
Capillary Columns in Gas Chromatographs
2.2 ISO Standard:
This test method is under the jurisdiction of ASTM Committee D02 on
Petroleum Products and Lubricants and is the direct responsibility of Subcommittee For referenced ASTM standards, visit the ASTM website, www.astm.org, or
D02.04.0H on Chromatographic Distribution Methods. contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Current edition approved Dec. 1, 2008. Published February 2009. DOI: 10.1520/ Standards volume information, refer to the standard’s Document Summary page on
D7500-08. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D7500–08
ISO 3170 Petroleum Liquids Manual Sampling 4.2 A sample aliquot is diluted with a viscosity reducing
solvent and introduced into the chromatographic system.
3. Terminology Sample vaporization is provided by separate heating of the
point of injection or in conjunction with column oven heating.
3.1 Definitions—This test method makes reference to many
4.3 The column oven temperature is raised at a specified
common gas chromatographic procedures, terms, and relation-
linear rate to affect separation of the hydrocarbon components
ships. For definitions of these terms used in this test method,
in order of increasing boiling point. The elution of sample
refer to Practices E355, E594, and E1510.
components is quantitatively determined using a flame ioniza-
3.2 Definitions of Terms Specific to This Standard:
tion detector. The detector signal is recorded as area slices for
3.2.1 area slice, n—the area resulting from the integration
consecutive retention time intervals during the analysis.
of the chromatographic detector signal within a specified
4.4 Retentiontimesofknownnormalparaffinhydrocarbons,
retention time interval. In area slice mode (see 6.4.1), peak
spanning the scope of the test method, are determined and
detection parameters are bypassed and the detector signal
correlated to their boiling point temperatures. The normalized
integralisrecordedasareaslicesofconsecutive,fixedduration
cumulative corrected sample areas for each consecutive re-
time intervals.
corded time interval are used to calculate the boiling range
3.2.2 corrected area slice, n—an area slice corrected for
distribution. The boiling point temperature at each reported
baseline offset by subtraction of the exactly corresponding area
percent off increment is calculated from the retention time
slice in a previously recorded blank (non-sample) analysis.
calibration.
3.2.3 cumulative corrected area, n—the accumulated sum
of corrected area slices from the beginning of the analysis
5. Significance and Use
through a given retention time, ignoring any non-sample area
(for example, solvent).
5.1 The boiling range distribution of medium and heavy
3.2.4 final boiling point (FBP), n—the temperature (corre-
petroleum distillate fractions provides an insight into the
spondingtotheretentiontime)atwhichacumulativecorrected
composition of feed stocks and products related to petroleum
area count equal to 99.5 % of the total sample area under the
refining processes (for example, hydrocracking, hydrotreating,
chromatogram is obtained.
visbreaking, or deasphalting). The gas chromatographic simu-
3.2.5 initial boiling point (IBP), n—the temperature (corre-
lationofthisdeterminationcanbeusedtoreplaceconventional
spondingtotheretentiontime)atwhichacumulativecorrected
distillation methods for control of refining operations.This test
area count equal to 0.5 % of the total sample area under the
method can be used for product specification testing with the
chromatogram is obtained.
mutual agreement of interested parties.
3.2.6 slice rate, n—the frequency used in sampling (analog)
5.2 This test method extends the scope of boiling range
the chromatographic detector signal during an analysis. The
determination by gas chromatography to include distillates
slice rate is expressed in Hz (for example integrations or slices
(IBP > 100°C) and heavy petroleum distillate fractions beyond
per second).
the scope of Test Method D2887 (538°C).
3.2.7 slice time, n—the inverse function of the acquisition
5.3 Boiling range distributions obtained by this test method
rate. It is the time duration of each sampling pulse usually
havenotbeenanalyzedforcorrelationtothoseobtainedbylow
expressed in seconds. The slice time is the time at the end of
efficiencydistillation,suchaswithTestMethodD86orD1160.
each contiguous area slice.
This test method does not claim agreement between these
3.2.8 total sample area, n—the cumulative corrected area,
physical distillations and simulated distillation. Efforts to
from the initial area point to the final area point, where the
resolve this question will continue. When successful resolu-
chromatographic signal has returned to baseline after complete
tions of the questions are determined, this test method will be
sample elution.
revised accordingly.
3.3 Abbreviations—A common abbreviation of hydrocar-
bon compounds is to designate the number of carbon atoms in
6. Apparatus
the compound. A prefix is used to indicate the carbon chain
6.1 Chromatograph—The gas chromatographic system
form, while a subscripted suffix denotes the number of carbon
used shall have the following performance characteristics:
atoms (for example n-C for normal-decane, i-C for iso-
10 14
6.1.1 Carrier Gas Flow Control—The chromatograph shall
tetradecane).
beequippedwithcarriergaspressureorflowcontrolcapableof
maintaining constant carrier gas flow to 61 % throughout the
4. Summary of Test Method
column temperature program cycle.
4.1 The boiling range distribution determination by distilla-
6.1.2 Column Oven—Capable of sustained and linear pro-
tion is simulated by the use of gas chromatography. A
grammed temperature operation from near ambient (for ex-
non-polar open tubular (capillary) gas chromatographic col-
ample, 30 to 35°C) up to 430°C.
umnisusedtoelutethehydrocarboncomponentsofthesample
6.1.3 Column Temperature Programmer—The chromato-
in order of increasing boiling point.
graph shall be capable of linear programmed temperature
operationupto430°Catselectablelinearratesupto10°C/min.
The programming rate shall be sufficiently reproducible to
obtain the retention time repeatability of 0.1 min (6 s) for each
Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,
4th Floor, New York, NY 10036, http://www.ansi.org. component in the calibration mixture described in 7.5.
D7500–08
TABLE 2 Typical Operating Conditions for Gas Chromatograph
6.1.4 Detector—Thistestmethodrequirestheuseofaflame
ionizationdetector(FID).Thedetectorshallmeetorexceedthe Column length, m 5
Column internal diameter, mm 0.53
following specifications in accordance with Practice E594.
Column material Metal
Check the detector according the instrument manufacturers
Stationary phase type methyl silicone
instructions. Film thickness, µm 0.09 to 0.17
Initial column temperature, °C 35
6.1.4.1 Operating Temperature—100 to 430°C.
Initial hold time, min 0
6.1.4.2 Connection of the column to the detector shall be
Final column temperature, °C 430
Final hold time, min 10
such that no temperature below the column temperature exists
Program rate, °C/min 10
between the column and the detector. Refer to Practice E1510
Injector initial temperature, °C 100
for proper installation and conditioning of the capillary col-
Injector final temperature, °C 430
umn. Injector program rate, °C/min 15
Detector temperature, °C 450
6.1.5 Sample Inlet System—Any sample inlet system ca-
A
Make-up gas flow, He or N2, mL/min 20
A
pable of meeting the performance specification in Annex A3
Hydrogen Flow, mL/min 45
A
Air Flow, mL/min 450
and execute the conditions of Table 2. Programmable tempera-
Carrier gas He
ture vaporization (PTV) and cool on-column (COC) injection
Carrier gas flow rate, constant flow, mL/min 19
systems have been used successfully. A,B
Sample size, µL 1.0
Sample concentration, % (m/m) 2
6.2 Microsyringe—A microsyringe with a 23-gauge or
Injector PTV or COC
smaller stainless steel needle is used for on-column sample
A
Consult with the manufacturer’s operations manual.
introduction. Syringes of 0.1 to 10-µL capacity are available.
B
Monitor skewness when varying the injection volume.
6.2.1 Automatic syringe injection is recommended to
achieve best precision.
6.3 Column—This test method is limited to the use of
6.4.1 Integrator/Computer System—Means shall be pro-
non-polar wall coated open tubular (WCOT) columns of high
vided for determining the accumulated area under the chro-
thermal stability. Fused silica (aluminum coated) and stainless
matogram. This can be done by means of an electronic
steel columns with 0.53 to 0.75-mm internal diameter have
integratororcomputer-basedchromatographydatasystem.The
been successfully used. Cross-linked or bonded 100 %
integrator/computer system shall have normal chromato-
dimethyl-polysiloxane stationary phases with film thickness of
graphic software for measuring the retention time and areas of
0.09 to 0.17 µm have been used. The column length and liquid
eluting peaks (peak processing mode). In addition, the system
phase film thickness shall allow the elution of C n-paraffin
shall be capable of converting the continuously integrated
(BP = 735°C). The column and conditions shall provide
detector signal into area slices of fixed duration (slice mode).
separation of typical petroleum hydrocarbons in order of
These contiguous area slices, collected for the entire analysis,
increasing boiling point and meet the column performance
are stored for later processing.Asimilar collection of contigu-
requirements ofA3.2.1. The column shall provide a resolution
ousslicesisalsocollectedfortheblankrun.Itisnecessarythat
not less than 2 and not higher than 4 using the test method
the number of slices collected for sample and blank analysis
operating conditions in Table 2.
are the same. The electronic range of the integrator/computer
6.4 Data Acquisition System:
(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
95.5% CI, °F 95.5% CI, °C
Average, Average,
operating software that allows a mathematical model of the baseline
% OFF Allowable Allowable
°F °C
profile to be stored in memory. This profile is automatically subtracted
Difference Difference
from the detector signal on subsequent sample runs to compensate for the
IBP 801 16 428 9
column bleed. Some integration systems also store and automatically
5 891 5 477 3
subtract a blank analysis from subsequent analytical determinations.
10 918 5 493 3
15 936 5 502 3
20 950 6 510 3
7. Reagents and Materials
25 963 6 518 4
30 975 7 524 4
7.1 Liquid Stationary Phase—A methyl silicone stationary
35 987 7 531 4
phase for the column.
40 998 8 537 4
7.2 Carrier Gases—Helium, of at least 99.999 % (v/v)
45 1008 8 543 4
50 1019 8 548 5
purity. Any oxygen present is removed by a chemical resin
55 1030 8 554 4
filter. (Warning—Follow the safety instructions from the filter
60 1040 8 560 4
supplier.) Total impurities not to exceed 10 mL/m . Helium or
65 1051 8 566 4
70 1062 8 572 4
Nitrogen (99.999 %) can also be used as detector makeup gas.
75 1073 9 578 5
7.3 Hydrogen—99.999 % Grade suitable for flame ioniza-
80 1086 8 585 4
85 1099 7 593 4 tion detectors. Total impurities not to exceed 10 mL/m .
90 1116 8 602 4
7.4 Compressed Air—Regulated for flame ionization detec-
95 1140 7 616 4
tors. Total impurities not to exceed 10 mL/m .
FBP 1213 32 655 18
A 7.5 Alkanes—Normal alkanes of at least 98 % (m/m) purity
Consensus results obtained from 14 laboratories in 2000 as reported in Test
Method D6352. from C to C ,C ,C ,C ,C ,C ,C ,C , and C , are
5 10 12 14 16 18 20 24 26 28
D7500–08
to be used with Polywax 655 or 1000. A solution of these 7.10 Cyclohexane (C H )—(99+ % pure) if necessary, use
6 12
alkanes is prepared by adding 500 mg of each alkane into a 20 in place of CS for the preparation of the calibration mixture.
mLvial.Additionally n-tetracontane (C ) can also be added to
7.11 A Gravimetric blend consisting of 2 distillation frac-
for ease of carbon counting. This solution is used to spike the
tions is used for system performance check (see A3.3).
Polywax solution.
7.6 Polywax 655 or 1000.
8. Sampling and Sample Preparation
7.7 Carbon Disulfide—Purity 99.7 % (v/v) minimum.
8.1 Unless otherwise specified, obtain the laboratory
(Warning—Extremely flammable and toxic by inhalation.)
samples by the procedures specified in ISO 3170 and place in
7.8 Calibration Mix—A suitable calibration mixture can be
glass or metal containers. Do not use plastic containers for
obtained by dissolving a hydrogenated polyethylene wax (for
sample storage to avoid contamination of the sample because
4 4
example,Polywax655 orPolywax1000 )inavolatilesolvent
of possible leaching of the plasticizer.
(for example, CS or cyclohexane). Solutions of 1 part Poly-
8.2 Sample Preparation—Sample aliquots are introduced
wax to 200 parts solvent can be prepared. Lower boiling point
into the gas chromatograph as solutions in a suitable solvent
paraffins will have to be added to as specified in 7.5. Fig. 5
(for example, CS ).
illustrates a typical calibration mixture chromatogram. The
8.3 Placeapproximately0.1to1gofthesamplealiquotinto
calibration mix is used to determine the column resolution,
a screw-capped or crimp-cap vial.
skewness of components, and retention time versus boiling
8.4 Dilute the sample aliquot to approximately 1–3
point calibration curve. Add 10 µL of the mixture of alkanes
weight % with the solvent, depending on the boiling point
prepared in 7.5.
distribution.
NOTE 2—Commercially available alkane standards are suitable for
8.5 Seal (cap) the vial, and mix the contents thoroughly to
column performance checks.
provide a homogeneous mixture. Warm the vial if necessary
NOTE 3—Calibration mixtures are commercially available.
initially to affect complete solution of the sample. Inspect the
7.9 Reference Oil 5010—A reference sample that has been
sample to ensure it is in stable solution at room temperature
analyzed by laboratories participating in the test method
prior to injection. If necessary, prepare a more dilute solution.
cooperative study. Consensus values for the boiling range
distribution of this sample are given Table 1.
9. Preparation of Apparatus
NOTE 4—The 5010 reference oil is available commercially.
9.1 Gas Chromatograph Setup—Set up and operate the gas
chromatograph in accordance with the manufacturer’s instruc-
tions.
PolywaxisaregisteredtrademarkofBakerPetrolite,12645WestAirportBlvd.,
NOTE 5—Typical operating conditions are shown in Table 2.
Sugar Land, TX 77478.
FIG. 1 Typical Sample Chromatogram which has a FBP of 700ºC
D7500–08
FIG. 2 Typical Calibration Curve of Retention Time versus Boiling Point
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.
toensurethatnoextraneouspeaksareproducedbytheseptum.
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.
9.5 Ensure that the system’s return to baseline is achieved NOTE 7—When C does not elute within the temperature program, it
is recommended to shorten the column. See manufacturer’s instructions.
near the end of the run and that the baseline shows no drift at
the final isothermal oven temperature.
10.3 Ensure the injection volume (or sample concentration)
9.6 Inspect and clean the jet periodically to avoid deposits chosen does not allow any peak to exceed the linear range of
that form on the jet from combustion of decomposition
the detector or overload the column.The skewness of all peaks
products from the column liquid stationary phase. These shall be maintained between 0.8–1.8. Values greater than 1.8
deposits will affect the characteristics of the detector response.
indicatethesampleistooconcentratedandaskewlessthan0.8
indicate severe tailing due to an old column or dirty liner or a
NOTE 6—The following parameters are affected by deposits on the jet:
poorly focused sample. As a guide, 0.2 to 1.0 µL of the
increase in inlet pressure, FID difficulty in lighting, increase in the CS
calibration mixture (7.8) has been found to be suitable for
response, and off-specification reference oil.To clean the jet, place it in an
columns with a film thickness ranging from 0.09 to 0.17 µm or
ultrasonic cleaner with a suitable solvent and use a cleaning wire if
necessary to remove column deposits. less. (See A3.4.)
D7500–08
FIG. 3 Peak Skewness for Calibration Mix Peak C
10.4 Record the retention time of each component and plot 11.2 Inspect the baseline at the end of the run for each
theretentiontimeversustheatmosphericboilingpointforeach solvent (blank) injected to ensure that it is constant and stable
component using the boiling points from Table 4. Typical and is void of extraneous peaks.
results of the calibration are shown in Table 5 and Fig. 2.
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
flow, leaks, and instrument drift.
reference oil 5010 and overlay the blank baseline. Enlarge the
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
NOTE 10—A sequence is a series of analysis. The length of the
of the run merges with the sample chromatogram as shown in
sequence 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 inAnnexA1 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
...