ASTM D7524-20

• Abstract:

  SIGNIFICANCE AND USE; 5.1 This test method will allow the determination of static dissipater additive in jet and middle distillate. These additives reduce the hazardous effects of static electricity generated by transfer and movement of jet and middle distillate fuels.; SCOPE; 1.1 This test method covers the determination of static dissipater additive (SDA) content of aviation turbine fuel and middle distillate fuels. ; 1.2 The precision of this test method has been established for aviation turbine fuel over the concentration range of 1 mg/L to 12 mg/L. Higher concentrations can be determined by dilution, but the precision of the test method will not apply. ; Note 1: The SDA used to develop this test method was STADIS 4502 for aviation fuels and STADIS 450 and 4252 for middle distillates. ; 1.3 The test method includes a procedure to concentrate the sulfonic acid component in the SDA prior to analysis. ; 1.4 The test method only applies to SDAs that contain alkyl substituted sulfonic acid. ; 1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. ; 1.6 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. ; 1.7 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.

• Status: Published
• Publication Date: 30-Sep-2020
• ICS: 75.160.20 - Liquid fuels
• Technical Committee: D02 - Petroleum Products, Liquid Fuels, and Lubricants
• Drafting Committee: D02.04.0C - Liquid Chromatography

• Refers: ASTM D4057-06(2011) - Standard Practice for Manual Sampling of Petroleum and Petroleum Products
• Effective Date: 01-Jun-2011
• Refers: ASTM D4057-95(2000) - Standard Practice for Manual Sampling of Petroleum and Petroleum Products
• Effective Date: 10-Apr-2000

Overview

ASTM D7524-20 is a standard test method developed by ASTM International for the determination of static dissipater additive (SDA) content in aviation turbine fuel and middle distillate fuels. The method utilizes high performance liquid chromatography (HPLC) to quantify specific SDAs that contain alkyl substituted sulfonic acids, helping ensure fuel safety and regulatory compliance. Static dissipater additives are critical for minimizing hazardous static electricity generated during the handling, transfer, and movement of jet and diesel fuels.

Key Topics

• Scope of Application:

  • Determination of SDA in aviation turbine fuels and middle distillates.
  • Applicable to SDAs containing alkyl substituted sulfonic acids.
  • Precision is established for aviation turbine fuel in the concentration range of 1 mg/L to 12 mg/L.

• Test Method Summary:

  • Samples are processed using solid phase extraction to concentrate the relevant sulfonic acid component.
  • The concentrate is analyzed by HPLC, employing a UV detector to measure peak areas that correspond to SDA levels.
  • Comparison to calibration standards enables quantification and reporting in mg/L.

• Significance and Use:

  • Ensures effective antistatic protection by verifying SDA content.
  • Supports safe fuel handling operations in the aviation and transport sectors.
  • Assures compliance with industry and regulatory requirements.

• Precision and Reliability:

  • Developed through interlaboratory studies for robust repeatability and reproducibility.
  • Results are reported in SI units, in line with international standardization practices.

Applications

ASTM D7524-20 is primarily applied in the following contexts:

• Fuel Quality Control:

  • Used by refineries, fuel suppliers, and independent laboratories to verify that aviation turbine fuels and diesel products contain appropriate SDA levels.
  • Ensures fuels meet industry safety standards, preventing incidents caused by static discharge.

• Aviation and Transport Safety:

  • Critical for the management of jet fuels (such as Jet A and Jet A-1) and other middle distillate fuels.
  • Maintains safe operational standards for airports, airlines, and military aviation.

• Regulatory Compliance:

  • Required documentation for regulatory bodies and fuel purchasers, confirming adherence to safety and quality specifications.
  • Supports recordkeeping and traceability in fuel supply chains.

• Research and Development:

  • Utilized in the formulation and testing of new or alternative static dissipater additives.

Related Standards

Several standards and practices complement or are referenced by ASTM D7524-20, enhancing its implementation and ensuring comprehensive fuel analysis:

• ASTM D4057: Practice for Manual Sampling of Petroleum and Petroleum Products
• ASTM D4177: Practice for Automatic Sampling of Petroleum and Petroleum Products
• EN ISO 3696: Water for Analytical Laboratory Use - Specifications and Test Methods
• IP 568/08: Determination of Static Dissipater Additives in Aviation Turbine Fuel and Middle Distillate Fuels – HPLC Method

Practical Value

Implementing ASTM D7524-20 provides the following practical benefits:

• Safety Assurance: Reduces risks inherent in fuel handling and transfer by ensuring adequate SDA presence.
• Reproducibility: Enables consistent, reliable test results across laboratories and fuel batches.
• Regulatory Alignment: Satisfies international requirements, including those established by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
• Operational Efficiency: Streamlines fuel quality control procedures with a standardized, HPLC-based analytical approach.

Keywords: static dissipater additive, SDA, aviation turbine fuel, middle distillate, HPLC, fuel safety, ASTM D7524-20, antistatic additive, fuel testing, regulatory compliance.

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: D7524 − 20
IP 568/08
Standard Test Method for
Determination of Static Dissipater Additives (SDA) in
Aviation Turbine Fuel and Middle Distillate Fuels—High
Performance Liquid Chromatograph (HPLC) Method
This standard is issued under the fixed designation D7524; 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* 2. Referenced Documents
2.1 ASTM Standards:
1.1 This test method covers the determination of static
D4057Practice for Manual Sampling of Petroleum and
dissipater additive (SDA) content of aviation turbine fuel and
Petroleum Products
middle distillate fuels.
D4177Practice for Automatic Sampling of Petroleum and
1.2 The precision of this test method has been established
Petroleum Products
for aviation turbine fuel over the concentration range of
2.2 ISO Standards:
1mg⁄L to 12mg⁄L. Higher concentrations can be determined
EN ISO 3696 Water for Analytical Laboratory Use—
by dilution, but the precision of the test method will not apply.
Specifications and Test Methods
NOTE 1—The SDAused to develop this test method was STADIS 450
2.3 Energy Institute Standards:
for aviation fuels and STADIS 450 and 425 for middle distillates.
IP 568/08Determination of the Static Dissipater Additives
1.3 The test method includes a procedure to concentrate the
(SDA) in Aviation Turbine Fuel and Middle Distillate
sulfonic acid component in the SDA prior to analysis.
Fuels—HPLC Method
1.4 ThetestmethodonlyappliestoSDAsthatcontainalkyl
3. Terminology
substituted sulfonic acid.
3.1 Definitions:
1.5 The values stated in SI units are to be regarded as
3.1.1 middle distillate fuels, n—generic refinery/supplier
standard. No other units of measurement are included in this
term that usually denotes a fuel primarily intended for use in
standard.
compression ignition/diesel engine applications, and also in
1.6 This standard does not purport to address all of the
non-aviation gas turbine engines and other non-automotive
safety concerns, if any, associated with its use. It is the
applications such as a burner fuel.
responsibility of the user of this standard to establish appro-
3.2 Definitions of Terms Specific to This Standard:
priate safety, health, and environmental practices and deter-
3.2.1 aviation turbine fuel, n—fuel used for powering jet
mine the applicability of regulatory limitations prior to use.
and turbo-prop engine aircraft.
1.7 This international standard was developed in accor-
3.2.2 conductivity improver additive, n—materialaddedtoa
dance with internationally recognized principles on standard-
fuel in very small amounts to increase its electrical conductiv-
ization established in the Decision on Principles for the
ity and thereby reduce relaxation time.
Development of International Standards, Guides and Recom-
3.2.2.1 Discussion—Conductivity improver additives are
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee. also known as static dissipater additives (SDAs) or antistatic
additives.
1 3
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 [e-mail]. For Annual Book of ASTM
Subcommittee D02.04.0C on Liquid Chromatography. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved Oct. 1, 2020. Published December 2020. Originally the ASTM website.
approved in 2010. Last previous edition approved in 2015 as D7524–10 (2015). Available from International Organization for Standardization (ISO), 1, ch. de
DOI:10.1520/D7524-20. la Voie-Creuse, Case postale 56, CH-1211, Geneva 20, Switzerland, http://
Stadis 450 and 425 are registered trademarks marketed by Innospec, Inc., www.iso.ch.
Innospec Manufacturing Park, Oil Sites Road, Ellesmere Port, Cheshire Ch65 4EY, Available from Energy Institute, 61 New Cavendish St., London, WIG 7AR,
UK. U.K., http://www.energyinst.org.uk.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7524 − 20
4. Summary of Test Method 6.5 Analytical Column —Any stainless steel HPLC column
packed with C alkyl-bonded reversed-phase, 5 µm particle
4.1 A solid phase extraction procedure is used to concen-
size, 250 mm × 4.6 mm ID is suitable, provided that it meets
tratethesulfonicacidcomponentofSDApresentinanaviation
the resolution requirements specified in 9.3.
turbinefuelormiddledistillatefuelsamplepriortoanalysis.A
6.6 HPLC Column Oven—Any suitable HPC column oven
fixed volume of the concentrated test fraction is injected into a
block heating or air circulating) capable of maintaining a
calibrated high performance liquid chromatograph.An analyti-
constant temperature of 61 °C within the range from 20 °C to
cal column is used to separate the sample components of the
40 °C.
test fraction by polarity.
NOTE 3—Alternative forms of temperature control are permitted, for
4.2 The analytical column is attached to a liquid chroma-
example, temperature-controlled laboratories.
tography detector where the sulfonic acid components are
6.7 Analytical Balance—Accurate to 60.0001 g.
readily detected by UV absorption as they elute from the
6.8 Solid Phase Extraction (SPE) Columns Reservoirs —
column. The electronic signal from the liquid chromatography
Amino bonded silica, 500 mg (A) or 100 mg (B) capacity.
detector is continually monitored by a chromatography data
6.8.1 Reservoirs with Connectors—Approximately 60 mL
system. The amplitudes of the signal (peak area) from the
capacity and connectors.
sulfonic acids are compared with those obtained from previ-
ously measured calibration standards in order to calculate the
6.9 Solid Phase Extraction Vacuum Manifold—Optional.
percent m/V SDA present in the sample.
6.10 Volumetric Flasks—Class A, of 2mL, 5mL, 10mL,
25mL, and 100mL capacity.
4.3 ThetestmethodonlyappliestoSDAsthatcontainalkyl
substituted sulfonic acids.
6.11 Graduated Pipette—Class A, of 1 mL, 2 mL, 10 mL,
and 50 mL capacity. Capable of delivering volumes of the
5. Significance and Use
range 0.5 mL to 4.0 mL with an accuracy of 60.0005 mL.
6.12 Measuring Cylinder—50 mL and 500 mL capacity.
5.1 This test method will allow the determination of static
dissipater additive in jet and middle distillate. These additives
6.13 pH meter.
reduce the hazardous effects of static electricity generated by
transfer and movement of jet and middle distillate fuels.
7. Reagents and Materials
7.1 Dinonylnaphthalene Sulfonic Acid (DINNSA)—50%
6. Apparatus
(m/m) solution in heptane.
6.1 High Performance Liquid Chromatograph (HPLC)—
7.2 Dodecylbenzene Sulfonic Acid (DDBSA)—70% (m/m)
Any HPLC capable of pumping an isocratic mobile phase at
solution in 2-propanol.
flow rates between 0.1mL⁄min and 1.5mL⁄min, with a preci-
7.3 Tetrahydrofuran—HPLC grade. (Warning—HPLC
sion better than 0.5% and a pulsation of < 1% full scale
grade tetrahydrofuran does not contain inhibitor, hence explo-
deflection under the test method conditions.
sive peroxides may form. Highly flammable and may cause
6.2 Variable Wavelength Ultraviolet Photometric Detector
irritation by inhalation, ingestion or skin contact.)
or Photometric DiodeArray Detector—Capableofoperationat
7.4 Hydrochloric Acid—37 %.
225nm and 234nm.
7.5 Methanol—HPLC grade. (Warning—Methanol is
6.3 Manual or Automatic Sample Injection Valve—Capable
highly flammable and toxic by inhalation, ingestion or skin
of injecting 10 µL to 25 µL, using either partial or full loop
contact.)
mode, with a repeatability 61%.
7.6 Orthophosphoric Acid.
6.3.1 An equal and constant volume of the calibration and
7.7 Sodium Hydroxide Pellets.
sample solutions is injected into the chromatograph. Both
manual and automatic sample injection systems (using either
7.8 Sodium Hydroxide Solution—Approximately 1 M. Dis-
complete or partial filling of the sample loop) will, when used
solve approximately4gof sodium hydroxide (see 7.7)in
correctly, meet the repeatability requirements specified in 6.3. approximately 100 mL of water.
7.9 Buffered Phosphoric Acid—Add approximately 2 mLof
NOTE 2—When using the partial loop-filling mode, it is recommended
orthophosphoric acid (see 7.6) to approximately 1 L of water
that the injection volume should be less than half the total loop volume.
Forcompletefillingoftheloop,bestresultsareobtainedbyoverfillingthe andbufferto2.5pHusingsodiumhydroxidesolution(see7.8).
loop at least six times.
6.4 Chromatography Data System—Anydatasystemcanbe
used,provideditiscompatiblewiththeliquidchromatography The sole source of supply of the apparatus known to the committee at this time
is Waters Corp. 34 Maple St., Milford, MA 01757. If you are aware of alternative
detector, has a minimum sampling rate of 1 Hz, and is able to
suppliers, please provide this information to ASTM International Headquarters.
measure peak areas and retention times and perform post-run
Your comments will receive careful consideration at a meeting of the responsible
data processing such as baseline correction and re-integration. technical committee, which you may attend.
D7524 − 20
TABLE 1 SPE Sample, Wash, and Elution Volumes
7.10 Isohexane—HPLC grade. (Warning—Isohexane is
highly flammable, and may cause irritation by inhalation, 500 mg 100 mg
SPE Column SPE Column
ingestion or skin contact.)
Sample volume 50 mL 10 mL
7.11 Solid Phase Extraction (SPE) Columns and
Isohexane/heptane wash 2 mL × 5 mL 2 mL × 2 mL
Methanol wash 5 mL 2 mL
Cartridges—Amino-bonded silica, 500 mg and 100 mg.
DINNSA/DDBSA eluate 5 mL 2 mL
7.12 Mobile Phase—Mix approximately 400 mL methanol
(see 7.5), approximately 400 mL THF (see 7.3), and approxi-
mately 50 mL of buffered phosphoric acid (see 7.9).
7.13 Nitrogen—Optional.
the500mgSPEcolumn(6.8(A))usingaconnector(6.8.1);the
NOTE 4—It is recommended practice to degas HPLC mobile phase
100mg SPE column has an integral reservoir.
before use; this can be done conveniently, on-line or off-line, by helium
9.2 Withapipette,transferthetestspecimen(seeTable1)to
sparging,vacuumdegassing,orultrasonicagitation.Afailuretodegasthe
mobile phase may lead to negative peaks. the SPE reservoir and allow the fuel to percolate through the
column under gravity or vacuum at a flow rate of 2mL⁄min or
7.14 Calibration Stock Solutions—Accurately weigh, to the
less. Discard the eluate.
nearest 0.0001 g, between 0.078 g and 0.082 g of DINNSA
solution (7.1) into a 100 mL volumetric flask and make up to 9.3 After all the fuel has eluted from the SPE column, rinse
the mark with heptane or mobile phase (7.12). Accurately thereservoirandSPEadsorbentwithportionsofisohexane(or
weigh, to the nearest 0.0001 g, between 0.028 g to 0.032 g of heptane) and then methanol, discarding the eluate (see Table
DDBSA solution (7.2) into a 100 mL volumetric flask and 1).
make up to the mark with heptane or mobile phase (7.12).
9.4 Elute the sulfonic acid (DINNSAor DDBSA) from the
7.15 Calibration Standards—From the calibration stock 100mg or 500mg SPE column using approximately 2mL or
solutions (7.14), prepare a set of five calibration standards in 5mL of mobile phase (7.12), respectively, and collect the
the mobile phase (7.12) to cover the concentration ranges eluate in a 2mLor 5mLvolumetric flask (6.10), making up to
indicated in the table: the mark with mobile phase (7.12) if necessary. Replace
stopper in volumetric flask and shake well.
SPE Column Size DINNSA DDBSA
500 mg 0.8 mg/L to 16 mg/L 0.7 mg ⁄L to 8.5 mg/L
9.5 Sample and eluent volumes are summarized in Table 1.
100 mg 0.32 mg/L to 9 mg/L 0.35 mg ⁄L to 4.5 mg ⁄L
NOTE 5—Asuggested procedure to prepare these standards is given in
10. Preparation of Apparatus
Annex A1.
10.1 Set up the pump, injector, detector, and data system
7.16 Calibration Check Solutions—2.0mg⁄L DINNSA and
according to the manufacturer’s instructions. Set the UV
2.8mg⁄L DBSA.
detector to 234nm for DINNSA and 225nm for DDBSA.
7.16.1 Prepare a 500mg⁄LDINNSAsolution by accurately
10.2 InstalltheHPLCcolumnandsetthemobilephaseflow
weighing, to the nearest 0.0001g, about 0.05g DINNSA(7.1)
into a 50mLvolumetric flask and making up to the mark with rate to 0.5mL⁄min.
heptane. Pipette 1mLof this solution into a 25mLvolumetric
NOTE 6—Set the temperature of the column oven, if used, to at least
flask and make up to the mark with heptane (20mg⁄L
10°C above ambient, for example, 40°C.
DINNSA solution). Pipette 1mL of the 20mg⁄L DINNSA
10.3 When operating conditions are steady, inject a fixed
solution into a 10mLvolumetric flask and make up to volume
volume (10µL to 25µL) of the middle calibration standard
with mobile phase (7.12) to give a 2.0mg⁄L check solution.
(7.15),andensurethechromatogramresemblesthoseshownin
7.16.2 Prepare a 700mg⁄L DDBSA solution by accurately
Fig. 1 (DINNSA) or Fig. 2 (DDBSA).
weighing, to the nearest 0.0001g, 0.05g DDBSA (7.2) into a
NOTE 7—The sulfonic acid peak around 4min may exhibit some
50mL volumetric flask and making up to the mark with
broadening due to the presence of isomers but no fine structure.
heptane. Pipette 1mLof this solution into a 25mLvolumetric
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D7524 − 10 (Reapproved 2015) D7524 − 20
IP 568/08
Standard Test Method for
Determination of Static Dissipater Additives (SDA) in
Aviation Turbine Fuel and Middle Distillate Fuels—High
Performance Liquid Chromatograph (HPLC) Method
This standard is issued under the fixed designation D7524; 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 Scope*
1.1 This test method covers the determination of static dissipater additive (SDA) content of aviation turbine fuel and middle
distillate fuels.
1.2 The precision of this test method has been established for aviation turbine fuel over the concentration range of 1 mg ⁄L to
12 mg ⁄L. Higher concentrations can be determined by dilution, but the precision of the test method will not apply.
2 2
NOTE 1—The SDA used to develop this test method was STADIS 450 for aviation fuels and STADIS 450 and 425 for middle distillates.
1.3 The test method includes a procedure to concentrate the sulfonic acid component in the SDA prior to analysis.
1.4 The test method only applies to SDAs that contain alkyl substituted sulfonic acid.
1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.6 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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
1.7 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.
2. Referenced Documents
2.1 ASTM Standards:
D4057 Practice for Manual Sampling of Petroleum and Petroleum Products
D4177 Practice for Automatic Sampling of Petroleum and Petroleum Products
This test method is under the jurisdiction of ASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of Subcommittee
D02.04.0C on Liquid Chromatography.
Current edition approved April 1, 2015Oct. 1, 2020. Published May 2015December 2020. Originally approved in 2010. Last previous edition approved in 20102015 as
D7524 – 10.D7524 – 10 (2015). DOI:10.1520/D7524-10R15.DOI:10.1520/D7524-20.
Stadis 450 and 425 are registered trademarks marketed by Innospec, Inc., Innospec Manufacturing Park, Oil Sites Road, Ellesmere Port, Cheshire Ch65 4EY, UK.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7524 − 20
2.2 ISO Standards:
EN ISO 3696 Water for Analytical Laboratory Use—Specifications and Test Methods
2.3 Energy Institute Standards:
IP 568/08 Determination of the Static Dissipater Additives (SDA) in Aviation Turbine Fuel and Middle Distillate Fuels—HPLC
Method
3. Terminology
3.1 Definitions:
3.1.1 middle distillate fuels, n—generic refinery/supplier term that usually denotes a fuel primarily intended for use in compression
ignition/diesel engine applications, and also in non-aviation gas turbine engines and other non-automotive applications such as a
burner fuel.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 aviation turbine fuel, n—fuel used for powering jet and turbo-prop engine aircraft.
3.2.2 conductivity improver additive, n—material added to a fuel in very small amounts to increase its electrical conductivity and
thereby reduce relaxation time.
3.2.2.1 Discussion—
Conductivity improver additives are also known as static dissipater additives (SDAs) or antistatic additives.
4. Summary of Test Method
4.1 A solid phase extraction procedure is used to concentrate the sulfonic acid component of SDA present in an aviation turbine
fuel or middle distillate fuel sample prior to analysis. A fixed volume of the concentrated test fraction is injected into a calibrated
high performance liquid chromatograph. An analytical column is used to separate the sample components of the test fraction by
polarity.
4.2 The analytical column is attached to a liquid chromatography detector where the sulfonic acid components are readily detected
by UV absorption as they elute from the column. The electronic signal from the liquid chromatography detector is continually
monitored by a chromatography data system. The amplitudes of the signal (peak area) from the sulfonic acids are compared with
those obtained from previously measured calibration standards in order to calculate the percent m/V SDA present in the sample.
4.3 The test method only applies to SDAs that contain alkyl substituted sulfonic acids.
5. Significance and Use
5.1 This test method will allow the determination of static dissipater additive in jet and middle distillate. These additives reduce
the hazardous effects of static electricity generated by transfer and movement of jet and middle distillate fuels.
6. Apparatus
6.1 High Performance Liquid Chromatograph (HPLC)—Any HPLC capable of pumping an isocratic mobile phase at flow rates
between 0.1 mL ⁄min and 1.5 mL ⁄min, with a precision better than 0.5 % and a pulsation of < 1 % full scale deflection under the
test method conditions.
6.2 Variable Wavelength Ultraviolet Photometric Detector or Photometric Diode Array Detector—Capable of operation at 225 nm
and 234 nm.
6.3 Manual or Automatic Sample Injection Valve—Capable of injecting 10 μL to 25 μL, using either partial or full loop mode, with
a repeatability 61 %.
Available from International Organization for Standardization (ISO), 1, ch. de la Voie-Creuse, Case postale 56, CH-1211, Geneva 20, Switzerland, http://www.iso.ch.
Available from Energy Institute, 61 New Cavendish St., London, WIG 7AR, U.K., http://www.energyinst.org.uk.
D7524 − 20
6.3.1 An equal and constant volume of the calibration and sample solutions is injected into the chromatograph. Both manual and
automatic sample injection systems (using either complete or partial filling of the sample loop) will, when used correctly, meet the
repeatability requirements specified in 6.3.
NOTE 2—When using the partial loop-filling mode, it is recommended that the injection volume should be less than half the total loop volume. For
complete filling of the loop, best results are obtained by overfilling the loop at least six times.
6.4 Chromatography Data System—Any data system can be used, provided it is compatible with the liquid chromatography
detector, has a minimum sampling rate of 1 Hz, and is able to measure peak areas and retention times and perform post-run data
processing such as baseline correction and re-integration.
6.5 Analytical Column —Any stainless steel HPLC column packed with C alkyl-bonded reversed-phase, 5 μm particle size, 250
mm × 4.6 mm ID is suitable, provided that it meets the resolution requirements specified in 9.3.
6.6 HPLC Column Oven—Any suitable HPC column oven block heating or air circulating) capable of maintaining a constant
temperature of 61 °C within the range from 20 °C to 40 °C.
NOTE 3—Alternative forms of temperature control are permitted, for example, temperature-controlled laboratories.
6.7 Analytical Balance—Accurate to 60.0001 g.
6.8 Solid Phase Extraction (SPE) Columns Reservoirs —Amino bonded silica, 6500500 mg (A) or 100 mg (B) capacity.
6.8.1 Reservoirs with Connectors—Approximately 60 mL capacity and connectors.
6.9 Solid Phase Extraction Vacuum Manifold—Optional.
6.10 Volumetric Flasks—Class A, of 2 mL, 5 mL, 10 mL, 25 mL, and 100 mL 2 mL, 5 mL, 10 mL, 25 mL, and 100 mL capacity.
6.11 Graduated Pipette—Class A, of 1 mL, 2 mL, 10 mL, and 50 mL capacity. Capable of delivering volumes of the range 0.5
mL to 4.0 mL with an accuracy of 60.0005 mL.
6.12 Measuring Cylinder—50 mL and 500 mL capacity.
6.13 pH meter.
7. Reagents and Materials
7.1 Dinonylnaphthalene Sulfonic Acid (DINNSA)—50 % (m/m) solution in heptane.
7.2 Dodecylbenzene Sulfonic Acid (DDBSA)—70 % (m/m) solution in 2-propanol.
7.3 Tetrahydrofuran—HPLC grade. (Warning—HPLC grade tetrahydrofuran does not contain inhibitor, hence explosive
peroxides may form. Highly flammable and may cause irritation by inhalation, ingestion or skin contact.)
7.4 Hydrochloric Acid—37 %.
7.5 Methanol—HPLC grade. (Warning—Methanol is highly flammable and toxic by inhalation, ingestion or skin contact.)
The sole source of supply of the apparatus known to the committee at this time is Waters Corp. 34 Maple St., Milford, MA 01757. If you are aware of alternative suppliers,
please provide this information to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of the responsible technical committee,
which you may attend.
D7524 − 20
7.6 Methanolic Hydrochloric Acid—Mix approximately 1 mL of hydrochloric acid (see 7.4) with approximately 9 mL of methanol
(see 7.5).
7.6 Orthophosphoric Acid.
7.7 Sodium Hydroxide Pellets.
7.8 Sodium Hydroxide Solution—Approximately 1 M. Dissolve approximately 4 g of sodium hydroxide (see 7.87.7) in
approximately 100 mL of water.
7.9 Buffered Phosphoric Acid—Add approximately 2 mL of orthophosphoric acid (see 7.77.6) to approximately 1l mL1 L of water
and buffer to 2.5 pH using sodium hydroxide solution (see 7.97.8).
7.10 Isohexane—HPLC grade. (Warning—Isohexane is highly flammable, and may cause irritation by inhalation, ingestion or
skin contact.)
7.11 Solid Phase Extraction (SPE) Columns and Cartridges—Amino-bonded silica, 500 mg and 100 mg.
7.12 Mobile Phase—Mix approximately 400 mL methanol (see 7.5), approximately 400 mL THF (see 7.3), and approximately 50
mL of buffered phosphoric acid (see 7.107.9).
7.13 Nitrogen—Optional.
NOTE 4—It is recommended practice to degas HPLC mobile phase before use; this can be done conveniently, on-line or off-line, by helium sparging,
vacuum degassing, or ultrasonic agitation. A failure to degas the mobile phase may lead to negative peaks.
7.14 Calibration Stock Solutions—Accurately weigh, to the nearest 0.0001 g, between 0.078 g and 0.082 g of DINNSA solution
(7.1) into a 100 mL volumetric flask and make up to the mark with heptane or mobile phase (7.137.12). Accurately weigh, to the
nearest 0.0001 g, between 0.028 g to 0.032 g of DDBSA solution (7.2) into a 100 mL volumetric flask and make up to the mark
with heptane or mobile phase (7.137.12).
7.15 Calibration Standards—From the calibration stock solutions (7.157.14), prepare a set of five calibration standards in the
mobile phase (7.137.12) to cover the concentration ranges indicated in the table:
SPE Column Size DINNSA DDBSA
500 mg 0.8 mg/mL to 16 0.7 mg ⁄mL to 8.5
mg/mL mg/mL
500 mg 0.8 mg/L to 16 mg/L 0.7 mg ⁄L to 8.5 mg/L
100 mg 0.32 mg/mL to 9 0.35 mg ⁄mL to
mg/mL 4.5 mg ⁄mL
100 mg 0.32 mg/L to 9 mg/L 0.35 mg ⁄L to 4.5 mg ⁄L
NOTE 5—A suggested procedure to prepare these standards is given in Annex A1.
7.16 Calibration Check Solutions—2.0 mg ⁄L DINNSA and 2.8 mg ⁄L DBSA.
7.16.1 Prepare a 500 mg ⁄L DINNSA solution by accurately weighing, to the nearest 0.0001 g, about 0.05 g DINNSA (7.1) into
a 50 mL volumetric flask and making up to the mark with heptane. Pipette 1 mL of this solution into a 25 mL volumetric flask and
make up to the mark with heptane (20 mg ⁄L DINNSA solution). Pipette 1 mL of the 20 mg ⁄L DINNSA solution into a 10 mL
volumetric flask and make up to volume with mobile phase (7.137.12) to give a 2.0 mg ⁄L check solution.
7.16.2 Prepare a 700 mg ⁄L DDBSA solution by accurately weighing, to the nearest 0.0001 g, 0.05 g DDBSA (7.2) into a 50 mL
volumetric flask and making up to the mark with heptane. Pipette 1 mL of this solution into a 25 mL volumetric flask and make
D7524 − 20
TABLE 1 SPE Sample, Wash, and Elution Volumes
500 mg 100 mg
SPE Column SPE Column
Sample volume 50 mL 10 mL
Isohexane/heptane wash 2 mL × 5 mL 2 mL × 2 mL
Methanol wash 5 mL 2 mL
DINNSA/DDBSA eluate 5 mL 2 mL
up to the mark with heptane (28 mg ⁄L DDBSA solution). Pipette 1 mL of the 28 mg/L DDBSA solution into a 10 mL volumetric
flask and make up to volume with mobile phase (7.137.12) to give a 2.8 mg ⁄L check solution.
7.17 Water—Grade 3 of EN ISO 3696.
8. Sampling
8.1 Use only representative samples obtained as described in Practice D4057 or D4177, unless otherwise specified.
9. Sample Preparation
9.1 Clamp the SPE column, 6.8(A) or 6.8(B), vertically or attach to a vacuum manifold if used. Add a 60 mL reservoir to the
500 mg SPE column (6.8(A)) using a connector (6.8.1); the 100 mg SPE column has an integral reservoir.
9.2 With a pipette, transfer the test specimen (see Table 1) to the SPE reservoir and allow the fuel to percolate through the column
under gravity or vacuum at a flow rate of 2 mL ⁄min or less. Discard the eluate.
9.3 After all the fuel has eluted from the SPE column, rinse the reservoir and SPE adsorbent with portions of isohexane (or
heptane) and then methanol, discarding the eluate (see Table 1).
9.4 Elute the sulfonic acid (DINNSA or DDBSA) from the 100 mg or 500 mg SPE column using approximately 2 mL or 5 mL
of mobile phase (7.137.12), respectively, and collect the eluate in a 2 mL or 5 mL volumetric flask (6.10), making up to the mark
with mobile phase (7.137.12) if necessary. Replace stopper in volumetric flask and shake well.
9.5 Sample and eluent volumes are summarized in Table 1.
10. Preparation of Apparatus
10.1 Set up the pump, injector, detector, and data system according to the manufacturer’s instruction
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