ASTM D8396-22

Standard Test Method for Group Types Quantification of Hydrocarbons in Hydrocarbon Liquids with a Boiling Point between 36 °C and 343 °C by Flow Modulated GCxGC – FID

SIGNIFICANCE AND USE
5.1 Accurate quantitative compositional information on hydrocarbon types can be useful in determining the effects of processes in the production of various finished fuels. Producers may require additional determinations such as n-paraffins, i-paraffins, naphthenes, and aromatics for process optimization. This information also may be useful for indicating the quality of fuels and for assessing the relative combustion properties of finished fuels. This test method can be used to make such determinations.
SCOPE
1.1 This test method covers the quantitative determination of total n-paraffins, total i-paraffins, total naphthenes (cycloparaffins), total one ring (1R) and total two ring plus (2R+) aromatic hydrocarbons in hydrocarbon liquids having a boiling point between 36 °C and 343 °C by GCxGC (flow modulated comprehensive two-dimensional gas chromatography). The method has been applied to aviation turbine fuels and is applicable to other low olefinic fuels in the stated boiling point range.  
1.2 This test method has an interim precision. An expanded full interlaboratory study is to be completed in    
Hydrocarbon Type  
Lower limit
(mass percent)  
Upper limit
(mass percent)  
Total i-paraffins  
22.0  
24.3  
Total n-paraffins  
19.0  
21.9  
Total naphthenes (cycloparaffins)  
34.3  
36.7  
Total one ring aromatics  
18.7  
21.8  
Total two ring plus aromatics  
0.5  
1.9  
1.3 This test method is applicable to other group type concentration ranges, to other hydrocarbon types such as selected individual components, for example, benzene, toluene, or n-paraffins by carbon number, or to other hydrocarbon streams; however, precision has not been determined at this time. A future ILS will include a variety of sample types and extend the reporting.  
1.4 This test method is not intended to determine unsaturated hydrocarbons, such as olefins, content which may interfere with the cycloparaffins; this test method is applicable to samples with D1319.  
1.5 This test method is not intended to determine FAME (fatty acid methyl esters). For such applications, Test Method D7797, IP 585, or equivalent test methods are available.  
1.6 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.7 This standard test method does not mandate or describe a specific software package for data processing and display. Any commercially available GCxGC software used for data processing and display shall meet the requirements for the calculation of the results. Appendix X1 provides some guidelines.  
1.8 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.9 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.

General Information

• Status: Published
• Publication Date: 31-Mar-2022
• ICS: 75.160.20 - Liquid fuels
• Technical Committee: D02 - Petroleum Products, Liquid Fuels, and Lubricants
• Drafting Committee: D02.04.0L - Gas Chromatography Methods

Relations

• Refers: ASTM D6300-24 - Standard Practice for Determination of Precision and Bias Data for Use in Test Methods for Petroleum Products, Liquid Fuels, and Lubricants
• Effective Date: 01-Mar-2024
• Refers: ASTM D4175-23a - Standard Terminology Relating to Petroleum Products, Liquid Fuels, and Lubricants
• Effective Date: 15-Dec-2023
• Refers: ASTM D6299-23a - Standard Practice for Applying Statistical Quality Assurance and Control Charting Techniques to Evaluate Analytical Measurement System Performance
• Effective Date: 01-Dec-2023
• Refers: ASTM D6300-23a - Standard Practice for Determination of Precision and Bias Data for Use in Test Methods for Petroleum Products, Liquid Fuels, and Lubricants
• Effective Date: 01-Dec-2023
• Refers: ASTM D4175-23e1 - Standard Terminology Relating to Petroleum Products, Liquid Fuels, and Lubricants
• Effective Date: 01-Jul-2023
• Refers: ASTM D6300-19a - Standard Practice for Determination of Precision and Bias Data for Use in Test Methods for Petroleum Products and Lubricants
• Effective Date: 01-Dec-2019
• Refers: ASTM E594-96(2019) - Standard Practice for Testing Flame Ionization Detectors Used in Gas or Supercritical Fluid Chromatography
• Effective Date: 01-Sep-2019
• Refers: ASTM D6299-17b - Standard Practice for Applying Statistical Quality Assurance and Control Charting Techniques to Evaluate Analytical Measurement System Performance
• Effective Date: 15-Dec-2017
• Refers: ASTM D6299-17a - Standard Practice for Applying Statistical Quality Assurance and Control Charting Techniques to Evaluate Analytical Measurement System Performance
• Effective Date: 15-Nov-2017
• Refers: ASTM D7797-17 - Standard Test Method for Determination of the Fatty Acid Methyl Esters Content of Aviation Turbine Fuel Using Flow Analysis by Fourier Transform Infrared Spectroscopy—Rapid Screening Method
• Effective Date: 01-May-2017
• Refers: ASTM D6299-17 - Standard Practice for Applying Statistical Quality Assurance and Control Charting Techniques to Evaluate Analytical Measurement System Performance
• Effective Date: 01-Jan-2017
• Refers: ASTM D7797-16a - Standard Test Method for Determination of the Fatty Acid Methyl Esters Content of Aviation Turbine Fuel Using Flow Analysis by Fourier Transform Infrared Spectroscopy—Rapid Screening Method
• Effective Date: 01-Oct-2016
• Refers: ASTM D7797-16 - Standard Test Method for Determination of the Fatty Acid Methyl Esters Content of Aviation Turbine Fuel Using Flow Analysis by Fourier Transform Infrared Spectroscopy—Rapid Screening Method
• Effective Date: 15-May-2016
• Refers: ASTM D6300-16 - Standard Practice for Determination of Precision and Bias Data for Use in Test Methods for Petroleum Products and Lubricants
• Effective Date: 01-Apr-2016
• Refers: ASTM D4307-99(2015) - Standard Practice for Preparation of Liquid Blends for Use as Analytical Standards
• Effective Date: 01-Oct-2015

Overview

ASTM D8396-22 is the international standard test method that provides a quantitative approach for determining hydrocarbon group types in liquid hydrocarbons using flow modulated comprehensive two-dimensional gas chromatography with flame ionization detection (GCxGC-FID). This method is specifically applicable to hydrocarbon liquids with boiling points between 36°C and 343°C, including but not limited to aviation turbine fuels and other low olefinic fuels. Accurate identification and quantification of hydrocarbon types-such as n-paraffins, i-paraffins, naphthenes (cycloparaffins), and aromatic hydrocarbons-are essential for both fuel quality control and process optimization in fuel production.

Key Topics

• Hydrocarbon Group Type Quantification: The standard outlines a test method to determine total n-paraffins, total i-paraffins, total naphthenes (cycloparaffins), one-ring (1R), and two-ring plus (2R+) aromatic hydrocarbons.
• Applicable Range: Effective for hydrocarbon liquids with less than 1% by mass total olefins and within the boiling point range of 36°C to 343°C.
• Precision and Repeatability: Although the standard provides interim precision based on single-laboratory data, expanded interlaboratory studies are planned for broader validation. The method delivers reliable quantification for group types within defined mass percent ranges.
• Interference and Limitations: The method is not intended for samples containing significant olefin content or for measuring fatty acid methyl esters (FAME). For such analyses, other referenced standards should be used.
• Software Flexibility: The standard does not require specific data processing software, allowing any commercially available GCxGC software that meets result calculation requirements.
• Health, Safety, and Environmental Considerations: Users are responsible for ensuring compliance with applicable safety and regulatory practices.

Applications

ASTM D8396-22 is highly relevant for:

• Fuel Quality Assessment: Determining the group composition of fuels, especially for finished products like aviation turbine fuels and mid-distillates, to evaluate combustion properties and meet regulatory requirements.
• Process Optimization: Tracking hydrocarbon type concentrations helps producers optimize refining and blending processes for improved fuel performance.
• Research and Development: Useful in laboratories and R&D settings for precise compositional analysis of hydrocarbon liquids.
• Statistical Quality Control: Supports ongoing fuel quality monitoring programs by providing data needed for statistical process control and assurance.

Typical uses include:

• Aviation turbine fuel group type analysis
• Quality control of refined or blended hydrocarbon liquids in the appropriate boiling range
• Supporting regulatory compliance and certification in petroleum products

Related Standards

For a comprehensive approach to hydrocarbon analysis and to address test objects outside the current scope of ASTM D8396-22, consider these referenced ASTM standard methods:

• ASTM D1319: Test Method for Hydrocarbon Types in Liquid Petroleum Products by Fluorescent Indicator Adsorption (useful for olefin content determination)
• ASTM D7797: Test Method for Determination of the Fatty Acid Methyl Esters Content of Aviation Turbine Fuel, applicable when FAME presence needs assessment
• ASTM D4175: Terminology Relating to Petroleum Products, Liquid Fuels, and Lubricants
• ASTM D4307: Practice for Preparation of Liquid Blends for Use as Analytical Standards
• ASTM D6299: Practice for Applying Statistical Quality Assurance and Control Charting Techniques
• ASTM D6730: Test Method for Determination of Individual Components in Spark Ignition Engine Fuels

Practical Value

Implementing ASTM D8396-22 equips laboratories and fuel producers with a standardized, repeatable method for precise group type quantification in hydrocarbon liquids. This enhances process control, supports compliance with industry regulations, and improves fuel quality assurance by delivering critical data on the detailed composition of fuel hydrocarbons. For sectors where hydrocarbon profiling is vital-such as aviation, refining, and transportation-this standard fosters confidence in product quality and supports informed decision-making.

Standards Content (Sample)

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:D8396 −22
Standard Test Method for
Group Types Quantification of Hydrocarbons in
Hydrocarbon Liquids with a Boiling Point between 36°C
and 343°C by Flow Modulated GCxGC–FID
This standard is issued under the fixed designation D8396; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 1.5 This test method is not intended to determine FAME
(fatty acid methyl esters). For such applications, Test Method
1.1 This test method covers the quantitative determination
D7797, IP 585, or equivalent test methods are available.
of total n-paraffins, total i-paraffins, total naphthenes
(cycloparaffins), total one ring (1R) and total two ring plus
1.6 The values stated in SI units are to be regarded as
(2R+) aromatic hydrocarbons in hydrocarbon liquids having a standard. No other units of measurement are included in this
boiling point between 36°C and 343°C by GCxGC (flow
standard.
modulated comprehensive two-dimensional gas chromatogra-
1.7 This standard test method does not mandate or describe
phy).Themethodhasbeenappliedtoaviationturbinefuelsand
a specific software package for data processing and display.
is applicable to other low olefinic fuels in the stated boiling
Any commercially available GCxGC software used for data
point range.
processing and display shall meet the requirements for the
1.2 This test method has an interim precision.An expanded
calculation of the results. Appendix X1 provides some guide-
full interlaboratory study is to be completed in <5 years. The
lines.
test method working concentration ranges in mass percent for
1.8 This standard does not purport to address all of the
which the interim precision has been determined are as
safety concerns, if any, associated with its use. It is the
follows:
responsibility of the user of this standard to establish appro-
Lower limit Upper limit
priate safety, health, and environmental practices and deter-
Hydrocarbon Type (mass percent) (mass percent)
mine the applicability of regulatory limitations prior to use.
Total i-paraffins 22.0 24.3
1.9 This international standard was developed in accor-
Total n-paraffins 19.0 21.9
Total naphthenes 34.3 36.7 dance with internationally recognized principles on standard-
(cycloparaffins)
ization established in the Decision on Principles for the
Total one ring aromatics 18.7 21.8
Development of International Standards, Guides and Recom-
Total two ring plus 0.5 1.9
aromatics
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
1.3 This test method is applicable to other group type
concentration ranges, to other hydrocarbon types such as
2. Referenced Documents
selectedindividualcomponents,forexample,benzene,toluene,
or n-paraffins by carbon number, or to other hydrocarbon
2.1 ASTM Standards:
streams; however, precision has not been determined at this
D1319Test Method for HydrocarbonTypes in Liquid Petro-
time. A future ILS will include a variety of sample types and
leum Products by Fluorescent Indicator Adsorption
extend the reporting.
D4175Terminology Relating to Petroleum Products, Liquid
Fuels, and Lubricants
1.4 This test method is not intended to determine unsatu-
D4307Practice for Preparation of Liquid Blends for Use as
rated hydrocarbons, such as olefins, content which may inter-
Analytical Standards
fere with the cycloparaffins; this test method is applicable to
D6299Practice for Applying Statistical Quality Assurance
samples with < 1% by mass total olefins as determined by
and Control Charting Techniques to Evaluate Analytical
D1319.
Measurement System Performance
D6300Practice for Determination of Precision and Bias
This test method is under the jurisdiction of ASTM Committee D02 on
Data for Use in Test Methods for Petroleum Products,
Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of
Liquid Fuels, and Lubricants
Subcommittee D02.04.0L on Gas Chromatography Methods.
D6730Test Method for Determination of Individual Com-
Current edition approved April 1, 2022. Published April 2022. DOI: 10.1520/
D8396-22. ponents in Spark Ignition Engine Fuels by 100-Metre
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D8396−22
Capillary (with Precolumn) High-Resolution Gas Chro- 3.2.7 modulation, n—the process of continuously collecting
matography and reinjecting per modulation period onto the second-
dimension column each fraction eluting from the first-
D7797Test Method for Determination of the Fatty Acid
dimension column.
Methyl Esters Content of Aviation Turbine Fuel Using
Flow Analysis by Fourier Transform Infrared
3.2.8 modulation delay, n—the time between the start of the
Spectroscopy—Rapid Screening Method
analysis and the first modulation.
E355PracticeforGasChromatographyTermsandRelation-
3.2.9 modulation period, n—the duration of a complete
ships
cycle of modulation, i.e., the time between two successive
E594Practice for Testing Flame Ionization Detectors Used
injections into the second column.
in Gas or Supercritical Fluid Chromatography
3.2.10 modulator, n—interface device between the two col-
umns in a comprehensive two-dimensional separation system
3. Terminology
that accumulates eluate of the first column for a brief period,
3.1 Definitions:
typically on the order of seconds, for fast reinjection into the
second column.
3.1.1 For definitions of terms used in this test method, refer
to Terminology D4175 and Practice E355.
3.2.11 monitor column, n—acolumnallowingrecordingthe
3.2 Definitions of Terms Specific to This Standard:
chromatogram from the first-dimension column.
3.2.1 comprehensive two-dimensional gas chromatography
3.2.12 peak or blob, n—a graphical representation in the
(GCxGC), n—an analytical technique which utilizes two dif-
two-dimensional chromatogram of a component eluting from
ferent columns with two distinct orthogonal polarity stationary
the GCxGC system; it is the sum of all the individual
phases that separate target components.
modulated cycles for that component.
3.2.1.1 Discussion—The effluent from the first-dimension
3.2.13 second-dimension column or secondary column,
column is collected, focused, and injected into the second-
n—inthistestmethod,anon-polar“boilingpoint”columnused
dimension column via a flow modulator. The effluent from the
to acquire the second-dimension separation data based upon
second-dimension is then directed into an FID. Using the two
differences in boiling point of the components.
columns of different polarity allows the separation of the
3.2.14 separation space, n—the plane region within the
specified compounds into compound classes and several indi-
two-dimensionalGCxGCplotinwhichcompoundsare,ormay
vidual compounds.
be, distributed.
3.2.2 first-dimension column, n—in this test method, a polar
3.2.15 template, n—a graphical object applied to a two-
column used to separate components based on differences in
dimensional GCxGC image that is used to identify the bound-
polarity of the compounds being separated. aries between different hydrocarbon types.
3.2.16 wrap-around, n—the occurrence or appearance of
3.2.3 flow modulator, n—GCxGC system in which the
second dimension peaks in consecutive modulation cycles,
interface device operates by a flow switching mechanism.
caused by second-dimension retention times that exceed the
3.2.4 GCxGC orthogonality, n—two chromatographic di-
modulation period.
mensions that employ different separation mechanisms to
determine elution times for the purpose of component identi-
4. Summary of Test Method
fication and in which each dimension can be treated as
4.1 Arepresentative sample is injected into a gas chromato-
statistically independent; in this test method, orthogonality is
graphthatisequippedwithatwo-stageflowmodulatorsystem,
achieved by using two column phases that are different in
first-dimension and second-dimension capillary GC columns,
polarity, such as a polar and non-polar column, to attain the
and a flame ionization detector (FID). The flow modulator
required resolution of the components.
serves as an interface between the two GC columns. The
3.2.5 hydrocarbon liquids, n—in this test method, fuels or
first-dimension column in the series is a high-resolution
process streams primarily composed of hydrogen and carbon,
capillary GC column coated with a polar stationary phase.The
with a boiling point in the range of approximately 36°C to
second-dimension GC column is a non-polar capillary. The
343°C and containing <1% by volume total olefins, such as
modulator repetitively accumulates and re-injects fractions
aviation fuels and kerosenes.
eluting off the first-dimension column onto the second-
dimension column, which is connected to the FID. The
3.2.5.1 Discussion—Applicablefuelsandprocessedstreams
outcome is a series of high-speed two-dimensional chromato-
may contain compounds of oxygen, nitrogen, or sulfur, or
grams from the second-dimension column from which peak
combinations thereof; however, these compounds, if present,
data are collected, and then transformed into two-dimensional
usually are spread over a wide range of boiling point and in
output by GCxGC software.
very low concentrations (for example, mg/kg) that cannot be
detected and do not interfere with this test method. More
NOTE 1—This test method uses flow modulation and intermediate
specialized techniques may be required for their detection. precision is based on such modulation. Precision and bias compared to
other modulators, such as thermal modulation, has not been determined.
3.2.6 injectiontime,n—thetimethatthevalveisswitchedto
Such other modulations may be tested in a future ILS to determine bias
the second-dimension column. and precision.
D8396−22
TABLE 1 Typical Chromatographic Operating Parameters Used in
4.1.1 The GCxGC software is used to identify the bound-
Developing the Test Method
aries between the different hydrocarbon types or the separated
Description
components, or both. The mass percent composition of the
Front S/SL Inlet
sample is obtained by using FID response factors and normal-
Heater 325 °C
ization. Inlets
Carrier Gas Helium
Split ratio 1:200
4.2 Tuning of the modulator is essential for proper opera-
st
1 dimension polar column
tion. To facilitate the system’s optimization, the chromato-
30 m x 250 µm polar column (e.g., polyethylene glycol)
Flow 1 mL/min
graphic system may be equipped with a monitor column and a
nd
2 dimension non-polar column
second FID. This monitor column allows recording the chro-
Columns 10 m x 320 µm non-polar column (e.g., polydimethylsiloxane)
matogram from the first-dimension column and aids in deter-
Flow 35 mL/min
Monitor column
mining the optimum modulation period. The apparatus prepa-
Deactivated Fused Silica
ration (Section 9) is based on a configuration including a
Flow 1 mL/min
monitorcolumn.Forconfigurationswithoutamonitorcolumn,
Temperature 40 °C
Equilibration time 1 min
we refer to the instrument manufacturer’s guidelines.
°C/min Next °C Hold
4.3 The application is validated by compliance with known
min
40 7.5
QC standards and samples.
Oven 3.2 45 0
Oven Ramp
4.2 120 0
5. Significance and Use
4.7 165 0
5.2 200 0
5.1 Accurate quantitative compositional information on hy-
5.7 270 3
drocarbon types can be useful in determining the effects of
Total run time 57.5
Front Front FID Back FID
processesintheproductionofvariousfinishedfuels.Producers
Heater 325 °C 325 °C
may require additional determinations such as n-paraffins,
Detector H2 flow 35.0 mL/min 35.0 mL/min
i-paraffins,naphthenes,andaromaticsforprocessoptimization.
Air flow 350.0 mL/min 350.0 mL/min
Make-up flow 20.0 mL/min 20.0 mL/min
This information also may be useful for indicating the quality
Valve Idle State Off
of fuels and for assessing the relative combustion properties of
Flow Modulation delay 0.1 min
finished fuels. This test method can be used to make such
Modulator Modulation period 3.5 s
Inject time 0.1 s
determinations.
6. Interferences
6.1 Olefins(forexample,alkenes,cycloalkenes,anddienes)
7.3.1 An injection volume of 0.1 µL has been found
are known interferences that can be misidentified as naph-
satisfactory.
thenes by this test method. Test method is limited to total
7.4 Electronic Data Acquisition System, shall meet or ex-
olefins content of <1% by volume as determined by Test
ceed the specifications required by the GC×GC software. X1.2
Method D1319.
contains information as guidelines.
7. Apparatus
7.5 GC×GC Flow Modulator—A device which precisely
transfers effluent from the first column to the second column
7.1 Gas Chromatograph, capable of operating at the condi-
withhighrepeatability.Precisionforthistestmethodusesflow
tions given in Table 1.
modulation; other modulation types have not been tested.
7.1.1 The typical system configuration includes a flow
modulator, a first-dimension column and a second-dimension
7.6 Gas Purifiers, to remove moisture and oxygen from
column (Fig. 1).
helium, moisture and hydrocarbons from hydrogen, and mois-
7.1.2 To achieve optimum separation for the different group
ture and hydrocarbons from air.
types, column dimensions and polarity must be selected such
8. Reagents and Materials
that sufficient orthogonality is achieved. Various column con-
figurations have been found satisfactory. Suitable non-polar
8.1 Air, compressed, <10 mg/kg each of total hydrocarbons
column phases are dimethylpolysiloxane or similar phases.
and water. (Warning—Compressed gas under high pressure
Polyethylene glycol, cyanopropyl/cyanopropyl phenyl, or
that supports combustion.)
equivalents are examples of suitable polar column phases.
8.2 CarrierGas,Helium,99.995%pure,<0.1mg/kgwater.
7.2 Gas Flow and Pressure Controllers, with adequate
(Warning—Compressed gas under high pressure.)
precision to provide reproducible flow and pressure of the
8.3 Make-up Gas, Nitrogen, 99.995 % pure.
carrier gas to the chromatographic system and meet quality
control requirements of the test method. 8.4 Hydrogen, 99.995 % pure, <0.1 mg⁄kg water.
(Warning—Extremely flammable gas under high pressure.)
7.3 Sample Introduction System—Using an automatic liquid
injector, the injection volume shall be chosen in a way such 8.5 Blank Run—An instrument blank under same operating
that the capacity of the column is not exceeded, and that the conditionsasusedfortheanalysisofthesamples,excepteither
linearity of the detector is valid and meets quality control usinganemptyGCvialorsettheautosamplerto“noinjection”
requirements of the test method. mode if software allows it.
D8396−22
FIG. 1Typical Instrument Configuration for a Flow Modulator used in this Test Method
2 TABLE 2 Typical Content of a Gravimetric Blend
8.6 Gravimetric Blend —A quantitative blend containing
Component Name Type Mass Percent
paraffins, naphthenes, and aromatic hydrocarbons prepared
n-Pentane C5 nP 0.50
gravimetrically in accordance with Practice D4307. Each
n-Hexane C6 nP 1.00
component used in the test mixture preparations shall have a
n-Heptane C7 nP 2.00
minimum purity of 99%. The actual concentration levels are n-Octane C8 nP 2.50
n-Nonane C9 nP 3.50
not critical, but the accepted reference values (ARV) shall be
n-Decane C10 nP 4.00
computed as per Practice D4307. A typical blend is shown in
n-Undecane C11 nP 4.75
Table 2 and Fig. 2. n-Dodecane C12 nP 5.25
n-Tridecane C13 nP 5.50
8.7 Reference Check Sample(s) , a known commercial or
n-Tetradecane C14 nP 5.00
n-Pentadecane C15 nP 4.25
equivalent sample(s) for which the accepted average values
n-Hexadecane C16 nP 3.50
(ARV) have been determined. Example is shown in Fig. 3 and
n-Heptadecane C17 nP 2.75
Table 3.
n-Octadecane C18 nP 2.00
n-Nonadecane C19 nP 1.00
NOTE2—TheblobsorpeaksinFig.2andFig.3withadotindicatorare
n-Eicosane C20 nP 0.50
the blobs or peaks counted. Appendix X2 gives more information on the
data acquisition and rejection of blobs or peaks. Benzene C6 A 0.50
Toluene C7 A 1.05
Ethylbenzene C8 A 2.00
9. Preparation of Apparatus
o-Xylene C8 A 2.75
9.1 Install and place the system in service in accordance 2-ethyltoluene C9 A 3.00
n-Propylbenzene C9 A 4.00
with the manufacturer’s instructions.
1.2.4-Trimethylbenzene C9 A 3.50
1.2.4.5- C10 A 2.75
9.2 Impurities in the carrier gas, hydrogen, or air will have
Tetramethylbenzene
a detrimental effect on the performance of the columns.
Pentamethylbenzene C11 A 2.00
Therefore, it is important to install efficient gas purifiers in the
Hexamethylbenzene C12 A 0.50
Naphthalene C10 2-ring A 0.55
gas lines as close to the system as possible and to use good
2-Ethylnaphthalene C12 2-ring A 0.55
quality gases. The carrier gas and hydrogen gas connection
lines shall be made of metal. Check that all gas connections,
Methylcyclohexane C7 N 1.25
Ethylcyclohexane C8 N 2.00
both exterior and interior to the system, are leak tight.
Propylcyclohexane C9 N 2.75
9.3 System Conditioning—Whengasconnectionshavebeen Butylcyclohexane C10 N 3.50
Pentylcyclohexane C11 N 4.00
disconnected or the flow turned off, as on initial start-up,
Hexylcyclohexane C12 N 1.50
condition the system by permitting carrier gas to flow through
Cyclohexane C6 N 1.25
the system for at least 30 min while the system is at ambient Cycloheptane C7 N 2.00
Cyclooctane C8 N 2.75
temperature.
Cyclododecane C12 N 1.25
Cyclopentadecane C15 N 0.75
9.4 Set the flow and temperatures. Table 1 contains typical
trans- C10 2-ring N 2.75
settings.
Decahydronaphthalene
Cyclopentylcyclohexane C11 2-ring N 0.75
9.5 Tuning the modulator to ensure full transfer of all
Bicyclohexyl C12N 2-ring N 2.35
analytes.
9.5.1 Using a monitor column: Total paraffins 48.00
Total naphthenes 28.85
(cycloparaffins or
2 cycloalkanes)
The sole source of supply of the commercial gravimetric blend and reference
Total aromatics 23.15
materials used in the development of this method known to the committee at this
Totals 100.00
time is PAC, 8824 Fallbrook Drive, Houston, TX, 77064. PAClp.com. If you are
aware of alternative suppliers, please provide this information to ASTM Interna-
tional Headquarters.Your comments will receive careful consideration at a meeting
of the responsible technical committee which you may attend.
D8396−22
FIG. 2Gravimetric Blend for Analysis by GCxGC–FID
FIG. 3GCxGC Chromatogram of Reference Check Sample by GCxGC-FID
TABLE 3 Typical Content of a Reference Check Sample
9.5.1.1 Tune the length of the monitor column such that all
A
Hydrocarbon Type ARV (mass percent)
components in the gravimetric blend (8.6) elute from the
Total i-paraffins 24.04
monitor column when the modulator is directing the flow from
Total n-paraffins 21.50
the first-dimension column to the monitor column.
Total naphthenes (cycloparaffins) 34.47
Total 1R aromatics 18.26
NOTE3—Whentheinstrumentisequippedwithonedetector,thetuning
Total 2R+ aromatics 1.74
of the modulator requires changing the column connected to the FID.
A
The ARV’s of the reference material are based on the results of six instruments.
During the tuning of first-dimension column the monitor column is
Reference material according to Practice D6299 will be developed during the pilot
connected to the FID, during all other operations, including sample
study or ILS, or both.
analysis, the second-dimension column is connected to the FID. 9.5.2 is
carried out with the monitor connected to the FID, 9.6 is carried out with
the second-dimension column connected to the FID, and 9.6.1 shall be
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carried out twice, first with the monitor column connected, and then a
too-fastoventemperatureprogram,andFig.9isanexampleof
second time with the second-dimension column connected. The require-
a too-slow oven temperature program.
ments for the output as described in these sections remains equal.
NOTE4—Wrap-aroundisexplainedwiththeredarrowinFig.7andFig.
9.5.2 Analyze the gravimetric blend (8.6) to confirm a
9.Atoo-slow oven temperature program causes too-late elution from the
correct length of the monitor column. Fig. 4 shows the correct
second-dimension column, and the peaks elute in the next modulation
monitor column length.All components appear in the monitor
period. The red arrow in Fig. 7 shows the position where the band of
n-paraffin peaks should appear with a correct oven temperature program.
column chromatogram under normal operating conditions.
The arrow in Fig. 9 illustrates a too-slow oven temperature program, the
9.5.3 Fig. 5 shows a too-long monitor column, some of the
band of n-paraffins elutes in the next modulation period.
componentsarealsodirectedtothesecond-dimensioncolumn.
9.7.1 Use the gravimetric blend (8.6) and the reference
The components are visible in both chromatograms. Shorten
check sample (8.7) to check the temperature program. Fig. 2
the column until all components elute from the first-dimension
and Fig. 3 are examples of a correct temperature program.
column.
9.7.2 Verify the isothermal time. The isothermal time is set
9.6 Tuning the modulation period. Set the modulation delay
at the elution time of the first component.
to a time period in which all components elute from the
9.8 SetthetemplatesintheGCxGCsoftwareusingvendor’s
first-dimension column to the second-dimension column.
recommendations. Fig. 3 shows the boundaries and fingerprint
9.6.1 Use the known gravimetric blend (8.6) to test the
obtained. This method allows the use of any combination of
modulation setting. When using a monitor column, no compo-
data handling and/or instrument control software capable of
nentsshallelutefromthemonitorcolumnthusensuringthatall
generating the necessary data and data handling to present
modulatedfractionsareretainedpriortobeinginjectedintothe
results in the GCxGC format (Appendix X1).
second-dimension column; if the modulation period is too
short, fractions may enter into the monitor column and be
detected. Fig. 6 shows a correct modulation period; the upper 10. Standardization
chromatogram is from the second-dimension column and
10.1 UsingtheprocedureoutlinedinSection11,analyzethe
shows all components from the gravimetric blend. The lower
gravimetric blend (8.6). Each individual component should be
chromatogramisfromthemonitorcolumnandshowsnopeaks
presentedasasingle(blob)peakbytheGCxGCsoftware(Fig.
from the gravimetric blend.
2).
9.7 Optimizing the oven temperature program: The opti- 10.1.1 Using the relative response factors in Table 4 or
mum temperature program uses all separation space while calculated from Eq 1, compare the reported values with the
avoiding wrap-around (Fig. 7). Fig. 8 is an example of a accepted reference values (ARV). The maximum acceptable
FIG. 4All Gravimetric Standard Components Elute from the Monitor Column, Peaks are only Appearing in 1-Dimension Chromatogram
(Red)
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FIG. 5Incorrect Monitor Column Length, Components Elute from both, the Monitor Column and the Second-Dimension Column
FIG. 6Chromatogram Example of a Correct Modulation Period: All Components
...