ASTM D8545-23e1

• Abstract:

  SIGNIFICANCE AND USE; 5.1 Specification D1655 provides a maximum permissible concentration (5.7 mg/L) of MDA in aviation turbine fuel. This test method will allow the quantification of MDA in aviation turbine fuels. The MDA additive is used for fuel thermal stability control and to reduce fuel degradation caused by the presence of trace metals (copper in particular) in aviation fuels.; SCOPE; 1.1 This test method covers the determination of the metal deactivator additive (MDA) content of aviation turbine fuels. The specific MDA determined and used to develop this test method is N,N′-disalicylidene-1,2-propanediamine. Other MDAs have not been tested by this test method. ; 1.1.1 This test method specifically covers the determination of uncomplexed MDA content in aviation turbine fuel. MDA is a chelator of divalent metal ions, and the MDA-metal ion complexed species content of aviation turbine fuel will not be accounted for by this test method. ; 1.2 This test method is divided into two procedures: (1) Procedure A uses a semi-portable capillary-liquid chromatography system (Capillary-HPLC) that may be used in the field or laboratory; (2) Procedure B uses a standard laboratory version of liquid chromatography (Conventional-HPLC). Procedures A and B have separate precisions. ; 1.3 The test method has an interim repeatability determined in accordance with Practice D6300. Based on the mean values of the samples used in the interim repeatability study, Procedure A is applicable in the range of 0.50 mg/mL to 10.0 mg/mL; the range for Procedure B is 0.60 mg/mL to 9.6 mg/mL. Higher concentrations can be determined by dilution, but the precision of the test method has not been determined. ; 1.3.1 An extended interlaboratory study (ILS) will be conducted in the future to determine the full repeatability and reproducibility and the final applicable concentration ranges. ; 1.3.2 The test method applies to MDA in petroleum-based aviation fuels and Synthetic Aviation Fuels (SAF). However, for the interim precision, a petroleum-based aviation fuel was used. Future ILS will include petroleum-based and SAFs. The test method is applicable to aviation fuels conforming to Specification D1655. ; 1.4 Appendix X2 indicates other additives that have been verified to not interfere with the analysis of this test method. ; 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-Nov-2023
• Technical Committee: D02 - Petroleum Products, Liquid Fuels, and Lubricants
• Drafting Committee: D02.04.0C - Liquid Chromatography

• Replaces: ASTM D8545-23 - Standard Test Method for Determination of the Metal Deactivator Additive (MDA) (N,N′-disalicylidene-1,2-propanediamine) Content in Aviation Turbine Fuel by High Performance Liquid Chromatography (HPLC)
• Effective Date: 01-Dec-2023
• Refers: ASTM D1655-24 - Standard Specification for Aviation Turbine Fuels
• Effective Date: 15-Mar-2024
• 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 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 D1655-23a - Standard Specification for Aviation Turbine Fuels
• Effective Date: 01-Oct-2023

Overview

ASTM D8545-23e1 is the standard test method developed by ASTM International for determining the content of the metal deactivator additive (MDA), specifically N,N′-disalicylidene-1,2-propanediamine, in aviation turbine fuel using High Performance Liquid Chromatography (HPLC). This method is essential for ensuring fuel quality and compliance with aviation fuel specifications, such as ASTM D1655, which limits the allowable MDA concentration in jet fuels to prevent negative impacts on fuel stability and degradation.

Key Topics

• MDA Significance: MDA is used in aviation turbine fuels to improve thermal stability and inhibit fuel degradation triggered by trace metals, particularly copper, which can catalyze oxidation reactions in fuel.
• Test Method Scope: This method quantifies uncomplexed MDA in petroleum-based and synthetic aviation turbine fuels but does not measure the MDA bound to metal ions.
• Procedures:
  • Procedure A: Uses a semi-portable capillary-HPLC system for field or laboratory analysis, suitable for concentration ranges from 0.50 mg/L to 10.0 mg/L.
  • Procedure B: Employs a conventional laboratory HPLC for ranges from 0.60 mg/L to 9.6 mg/L.
• Sample Handling: The test involves precise sample preparation, including the use of PTFE syringe filters and glass containers to avoid adsorption losses and maintain sample integrity.

Applications

• Aviation Fuel Quality Assurance: The method helps ensure that aviation turbine fuels comply with specification limits, thus protecting engines from deposit formation and performance loss.
• Thermal Stability Management: By accurately determining MDA levels, fuel producers and users can optimize additive dosing to counteract trace metal effects, minimizing risks of oxidation and polymerization.
• Laboratory and Field Use: The two outlined procedures support flexibility, allowing for both on-site (field deployable, capillary-HPLC) and laboratory-based (conventional HPLC) applications in refineries, airports, and quality control labs.
• Synthetic and Conventional Fuels: Applicable to fuels conforming to ASTM D1655, including both traditional petroleum and emerging synthetic aviation fuels (SAFs), supporting evolving industry trends.

Related Standards

• ASTM D1655: Specification for Aviation Turbine Fuels sets limits for additives like MDA.
• ASTM D4052: Method for measuring density and API gravity of liquids using digital density meters; relevant for preparing calibration standards.
• ASTM D4057 & D4177: Practices for manual and automatic fuel sampling, ensuring representative and uncontaminated samples.
• ASTM D4175: Terminology standard for petroleum products and fuels, providing key definitions in the context of this test method.
• ASTM D6299: Practice for statistical quality assurance, supporting implementation of control charts and monitoring analytical performance.
• ASTM D6300: Practice for determination of precision and bias in test methods, referenced for establishing repeatability.

Practical Value

Implementing ASTM D8545-23e1 safeguards aviation fuel system integrity by providing a precise, standardized protocol to monitor and control MDA additive concentrations. Compliance ensures reduced risk of fuel degradation, engine fouling, and operational disruptions. This standard is vital for jet fuel suppliers, refiners, and aviation quality assurance professionals seeking to meet stringent fuel specifications, maintain regulatory compliance, and support safe, reliable aircraft operations.

Keywords: ASTM D8545-23e1, metal deactivator additive, MDA, aviation turbine fuel, high performance liquid chromatography, HPLC, jet fuel additives, fuel quality control, ASTM D1655, fuel thermal stability

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.
´1
Designation: D8545 − 23
Standard Test Method for
Determination of the Metal Deactivator Additive (MDA) (N,N'-
disalicylidene-1,2-propanediamine) Content in Aviation
Turbine Fuel by High Performance Liquid Chromatography
(HPLC)
This standard is issued under the fixed designation D8545; 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.
ε NOTE—Editorially corrected 5.1 in February 2024.
1. Scope used. Future ILS will include petroleum-based and SAFs. The
test method is applicable to aviation fuels conforming to
1.1 This test method covers the determination of the metal
Specification D1655.
deactivator additive (MDA) content of aviation turbine fuels.
The specific MDA determined and used to develop this test 1.4 Appendix X2 indicates other additives that have been
method is N,N'-disalicylidene-1,2-propanediamine. Other verified to not interfere with the analysis of this test method.
MDAs have not been tested by this test method.
1.5 The values stated in SI units are to be regarded as
1.1.1 This test method specifically covers the determination
standard. No other units of measurement are included in this
of uncomplexed MDA content in aviation turbine fuel. MDA is
standard.
a chelator of divalent metal ions, and the MDA-metal ion
1.6 This standard does not purport to address all of the
complexed species content of aviation turbine fuel will not be
safety concerns, if any, associated with its use. It is the
accounted for by this test method.
responsibility of the user of this standard to establish appro-
1.2 This test method is divided into two procedures: (1)
priate safety, health, and environmental practices and deter-
Procedure A uses a semi-portable capillary-liquid chromatog-
mine the applicability of regulatory limitations prior to use.
raphy system (Capillary-HPLC) that may be used in the field or
1.7 This international standard was developed in accor-
laboratory; (2) Procedure B uses a standard laboratory version
dance with internationally recognized principles on standard-
of liquid chromatography (Conventional-HPLC). Procedures A
ization established in the Decision on Principles for the
and B have separate precisions.
Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical
1.3 The test method has an interim repeatability determined
in accordance with Practice D6300. Based on the mean values Barriers to Trade (TBT) Committee.
of the samples used in the interim repeatability study, Proce-
dure A is applicable in the range of 0.50 mg ⁄mL to 2. Referenced Documents
10.0 mg ⁄mL; the range for Procedure B is 0.60 mg ⁄mL to
2.1 ASTM Standards:
9.6 mg ⁄mL. Higher concentrations can be determined by
D1655 Specification for Aviation Turbine Fuels
dilution, but the precision of the test method has not been
D4052 Test Method for Density, Relative Density, and API
determined.
Gravity of Liquids by Digital Density Meter
1.3.1 An extended interlaboratory study (ILS) will be con-
D4057 Practice for Manual Sampling of Petroleum and
ducted in the future to determine the full repeatability and
Petroleum Products
reproducibility and the final applicable concentration ranges.
D4175 Terminology Relating to Petroleum Products, Liquid
1.3.2 The test method applies to MDA in petroleum-based
Fuels, and Lubricants
aviation fuels and Synthetic Aviation Fuels (SAF). However,
D4177 Practice for Automatic Sampling of Petroleum and
for the interim precision, a petroleum-based aviation fuel was
Petroleum Products
D6299 Practice for Applying Statistical Quality Assurance
and Control Charting Techniques to Evaluate Analytical
This test method is under the jurisdiction of ASTM Committee D02 on
Measurement System Performance
Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of
D6300 Practice for Determination of Precision and Bias
Subcommittee D02.04.0C on Liquid Chromatography.
Data for Use in Test Methods for Petroleum Products,
Current edition approved Dec. 1, 2023. Published January 2024. DOI: 10.1520/
D8545-23E01. Liquid Fuels, and Lubricants
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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D8545 − 23
3. Terminology usually is used with a laboratory apparatus and may not be
portable (Procedure B).
3.1 Definitions:
3.1.1 For definitions of terms used in this test method, refer
4. Summary of Test Method
to Terminology D4175.
3.1.2 aviation turbine fuel, n—refined petroleum distillate,
4.1 A fuel sample is filtered to remove small particulates. A
generally used as a fuel for aviation turbines. fixed volume of the filtered test sample is injected into a
3.1.2.1 Discussion—In this test method, aviation turbine
calibrated high performance liquid chromatograph. An analyti-
fuel refers to petroleum-based aviation fuels and synthetic cal column is used to separate the sample components of the
aviation fuels.
test sample by polarity.
3.1.3 metal deactivator additive (MDA), n—a fuel additive
4.2 The analytical column is interfaced to a liquid chroma-
that counteracts the effect of trace metals in the bulk fuel.
tography detector where the MDA is detected by UV absorp-
3.1.3.1 Discussion—Trace metals such as copper, cadmium,
tion as it elutes from the column. Uncomplexed MDA absorbs
iron, cobalt and zinc may have an adverse effect on fuel
light at a maximum of approximately 315 nm. The electronic
thermal and storage stability as those metals can catalyze
signal from the liquid chromatography detector is monitored
oxidation reactions that lead to degradation of the fuel.
continuously by a chromatography data system. The ampli-
3.1.3.2 Discussion—In this test method it refers to N,N'-
tudes of the signal (peak area) from the MDA are compared
disalicylidene-1,2-propanediamine; other commercially used
with peak areas obtained from previously measured external
MDAs have not been tested.
calibration standards in order to calculate the concentration of
mg/L MDA present in the sample.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 capillary-HPLC, n—high performance liquid chroma-
5. Significance and Use
tography using a capillary separation column with typical
1 mm or less internal diameter.
5.1 Specification D1655 provides a maximum permissible
3.2.1.1 Discussion—In this test method capillary-HPLC is
concentration (5.7 mg ⁄L) of MDA in aviation turbine fuel. This
used in a semi-portable field applicable apparatus (Procedure
test method will allow the quantification of MDA in aviation
A).
turbine fuels. The MDA additive is used for fuel thermal
3.2.2 conventional-HPLC, n—high performance liquid stability control and to reduce fuel degradation caused by the
chromatography with separation column with >1 mm internal presence of trace metals (copper in particular) in aviation fuels.
diameter.
3.2.2.1 Discussion—In this test method such application
PROCEDURE A: CAPILLARY-HIGH PERFORMANCE LIQUID CHROMATOGRAPHIC SYSTEMS (SEMI-
PORTABLE CAPILLARY-HPLC)
6. Apparatus
6.1 High Performance Liquid Chromatograph (HPLC) — 6.4 Chromatography Data System—Any data system can be
Any HPLC capable of column temperature control at 55 °C 6
used, provided it is compatible with the liquid chromatography
1 °C and pumping an isocratic mobile phase at flow rates
detector, has a minimum sampling rate of at least 8 Hz, and is
between 1 μL ⁄min and 10 μL ⁄min, with a precision better than
able to measure peak areas and retention times and perform
0.5 % and a pulsation of <1 % full scale deflection under the
post-run data processing such as baseline correction,
test method conditions.
integration, calibration, and quantitation.
6.2 Ultraviolet Photometric Detector or Photometric Diode
6.5 Analytical Column—GL Sciences Inertsil Diol Cat. No.
Array Detector (DAD)—Capable of operation at 315 nm 6
5020-11523, 3 μm particle size, 50 mm by 0.3 mm ID or
5 nm.
equivalent. Other columns that resolve MDA from other fuel
components as shown in Fig. 1 and meet all other quantitative
6.3 Manual or Automatic Sample Injection Valve—Capable
and quality control requirements described in this method may
of injecting 2 μL to 3 μL, using either partial or full loop mode,
be used.
with a repeatability 61 %.
6.3.1 Both manual and automatic sample injection systems
6.6 HPLC Column Oven—Any suitable HPLC column oven
will, when used correctly, meet the repeatability requirements
(block heating or air circulating) capable of maintaining a
specified in 6.3.
constant temperature of 55 °C 61 °C.
6.7 Analytical Balance—Accurate to 60.00001 g
(0.01 mg).
The sole source of supply of the turnkey apparatus known to the committee at
this time is Axcend Corp. 5252 N. Edgewood Dr., #185, Provo, UT 84604. If you
6.8 Syringes—100 μL or 25 μL such as Hamilton’s 81075
are aware of alternative suppliers, please provide this information to ASTM
and 80275 (gas tight syringes with 2 in. 22-gauge needles and
International Headquarters. Your comments will receive careful consideration at a
meeting of the responsible technical committee, which you may attend. blunt tips) or equivalent.
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D8545 − 23
7.11 Syringe Filters—0.2 μm or 0.22 μm PTFE syringe
filters. MilliporeSigma Millex Syringe Filter SLLG033NB
was found adequate for this test method; equivalent filter(s)
that do not adsorb MDA may be used.
7.12 Disposable Syringe—1 mL to 5 mL polypropylene sy-
ringe with polypropylene piston for use with syringe filters
(7.11) to filter samples. Disposable needles to use with the
syringe for drawing samples are also useful.
7.13 Calibration Stock Standards and Calibration
Standards—All standards are prepared in kerosene. This test
method requires at least three calibration standards prepared in
kerosene at approximately concentrations of 0.5 mg ⁄L,
NOTE 1—The absorbance wavelength used in 315 nm.
6.0 mg ⁄L, and 10.0 mg ⁄L. Recommended procedure to prepare
FIG. 1 Typical Semi-portable Capillary-HPLC Chromatogram of
the Calibration Standards and the Calibration Check Standard
5.7 mg ⁄L MDA Calibration Standard in Kerosene
is given in Appendix X1. Ensure that MDA is well mixed by
sonication or vortex in the preparation of the stock solutions.
Accurately weigh, to the nearest 0.01 mg. For kerosene a
density of 0.80 g ⁄mL at 20 °C is used to convert masses to
6.9 Appropriately sized glass containers or vials that can be
volumes in the preparation of the standards. If the density of
sealed to avoid evaporation for the preparation of standards.
the kerosene is different than 0.77 g ⁄mL to 0.83 g ⁄mL, obtain
its density by Test Method D4052 and use its value in the
7. Reagents and Materials
conversion of mass to volume to prepare the calibration
7.1 N,N'-disalicylidene-1,2-propanediamine (MDA)—98 %
standards (see Appendix X1).
or greater purity. (Warning—Combustible liquid, keep away 7.13.1 For capping the standard containers or vials, PTFE
from open flames, hot surfaces and sources of ignition; wear
lined cap are recommended.
personal protective equipment; may cause irritation by 7.13.2 Calibration Check Standard—Prepare a separate
inhalation, ingestion or skin contact. CAS# 94-91-7). 5.7 mg ⁄L MDA in kerosene (see Appendix X1 for recom-
mended preparation).
7.2 Heptane—HPLC grade. (Warning—Heptane is highly
7.13.3 Commercially prepared NIST traceable standards
flammable, and may cause irritation by inhalation, ingestion, or
using reagents that meet or exceed the purity requirements of
skin contact. CAS# 142-82-5).
this test method may be used as an alternative to the in-house
prepared standards. Such standards must be prepared and
7.3 Kerosene—Reagent grade (Warning—Kerosene is
stored in glass and may be glass sealed for stability and to
highly flammable, and may cause irritation by inhalation,
prevent evaporation.
ingestion, or skin contact. CAS# 8008-20-6). Available from
several suppliers.
8. Sampling
7.4 n-Propanol—HPLC grade. (Warning—n-Propanol is
8.1 Use only representative samples obtained as described
highly flammable and toxic by inhalation, ingestion, or skin
in Practices D4057 or D4177, unless otherwise specified. MDA
contact. CAS# 71-23-8).
may adsorb readily on container surfaces, etc. It is recom-
7.5 Acetonitrile—HPLC grade. (Warning—Acetonitrile is
mended that containers made of glass be used. Do not use
highly flammable and toxic by inhalation, ingestion, or skin metal containers to avoid possible reaction and/or loss of
contact. CAS# 75-05-8). MDA.
7.6 N,N,N',N'',N''-Pentamethyldiethylenetriamine (PM-
9. Sample Preparation
DETA)—98 % or greater purity. (Warning—Combustible liq-
9.1 Draw 1 mL to 5 mL of a representative well-mixed
uid; harmful if ingested; causes severe skin burns and eye
aviation fuel sample into a disposable syringe. Place a syringe
damage; may cause respiratory irritation. CAS# 3030-47-5).
filter (7.11) on the outlet of the syringe, filter approximately
7.7 Ethanol—HPLC grade. (Warning—Ethanol is highly
0.5 mL or more to waste, and collect the next 1 mL or more
flammable and toxic by inhalation, ingestion, or skin contact,
into a vial for subsequent HPLC analysis.
CAS# 64-17-5).
10. Preparation of Apparatus
7.8 Mobile Phase A—Heptane with 2.0 % (vol/vol) acetoni-
trile. 10.1 Set up the pump, injector, detector, and data system
according to the manufacturer’s instructions. Set the UV
7.9 Mobile Phase B—Heptane with 8 % (vol/vol)
detector to 315 nm if a variable wavelength option is present.
n-Propanol and 2.0 % (vol/vol) acetonitrile.
7.10 Wash Solution—Ethanol with 1.0 % (vol/vol) PM-
DETA. MilliporeSigma is a registered trademark of Merck KGAA.
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D8545 − 23
TABLE 2 Example Capillary-HPLC Operating Conditions
10.2 Install the HPLC column and set the operating condi-
tions according to Table 1 and Table 2. Mobile Phase B:
Mobile Phase A:
Heptane with 8 %
Time (min) Heptane with 2.0 %
10.3 After the column temperature has stabilized, analyze
n-Propanol, and 2.0 %
Acetonitrile (Percent)
acetonitrile (Percent)
the middle calibration standard (for example, 6 mg ⁄L) by
0.00 97 3
flushing the injector loop first with 100 μL of the standard and
0.5 97 3
then starting the analysis. The excess volume flushes the
4 3 97
7 3 97
system’s valve loop of 2 μL to 3 μL used in the capillary-
HPLC. A typical chromatogram, retention time and peak shape
of MDA in shown in Fig. 1. A low intensity impurity
component from certain petroleum derived fuels may be
present and elute near the MDA, but is not integrated for the
analysis.
10.4 Peak Asymmetry Factor—Using the middle calibration
standard chromatogram from 10.3, determine the peak asym-
metry factor (A ) as described below and in Fig. 2:
s
A 5 T⁄F (1)
s
FIG. 2 Peak Asymmetry Determination
where:
T = distance from the peak midpoint (perpendicular from the
a signal to noise ratio (S/N) greater than 10 for the lowest
peak highest point) to the trailing edge of the peak
concentration 0.5 mg ⁄L calibration standard, as indicated in
measured at 10 % of peak height, and
Fig. 3.
F = distance from the leading edge of the peak to the peak
10.8 Inject the calibration check standard five times to
midpoint (perpendicular from the peak highest point)
confirm system repeatability, calculate the area relative stan-
measured at 10 % of peak height.
dard deviation and confirm it to be less than 1 %.
Ensure that A is < 1.5.
s
10.9 After completing the steps in this section, the system is
10.5 Cleaning the Injection System—Flush the injection
ready for calibration (Section 11).
loop with at least 100 μL of the wash solution. The amount of
the wash solution used to flush may be increased if blanks
11. Calibration
indicate potential carryover of MDA.
11.1 To determine the concentration of MDA in the fuel
10.5.1 The syringe and injection loop should be well rinsed
samples by external standardization, similar and constant
with sample before running each sample. It is a good practice
volumes of the calibration standards and the fuel samples are
to run a single injection of a sample to make sure the wash
injected into the liquid chromatograph. For the calibration,
solution is completely rinsed out before analyzing a sample.
analyze the set of the three calibration standards (7.13) and
10.6 Analysis of a Blank—Inject heptane and ensure that
establish the standard linear regression line by plotting the peak
MDA is detected at <0.1 mg ⁄L.
area of the MDA versus the corresponding known concentra-
10.6.1 The required number and frequency of blanks nec-
tions of each standard. An example of the calibration line is
essary to ensure a carryover of <0.1 mg ⁄L for standards and
given in Fig. 4.
samples may need to be determined for a given system to
11.2 The correlation r value for the calibration line ob-
ensure quality of data. Once the number and frequency are
tained shall be at least 0.997 or better. See Fig. 4 for an
determined it may be implemented as part of the routine
example.
analysis protocol. It may be helpful also to use the wash
11.3 The value of the absolute term intercept/slope (b/m)
solution before analysis of blanks, standards and samples. See
shall be equal to or less than 0.20 where b is the y-intercept and
10.5 for precautions after using the wash solution.
m is the slope of the linear fit line. The calculated b/m value is
10.7 Determination of System Detectability—After ensuring
based on plotting Y = area, and X = concentration. For example,
that analysis of a blank sample yields <0.1 mg ⁄L MDA,
analyze the lowest concentration calibration standard
(0.5 mg ⁄L) to check system sensitivity. The detector shall have
TABLE 1 Example Capillary-HPLC Operating Conditions
Column Temperature 45 °C
Flow Rate 6 μL ⁄min
Target Pressure 6205 kPa (900 psi)
Wavelength 315 nm
Equilibration Time 1 min
Injection size μL 2
FIG. 3 Determination of Signal to Noise Ratio (S/N)
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D8545 − 23
or troubleshoot system and repeat this check again before
proceeding with the analysis of fuel samples.
12.2 Analysis of Samples:
12.2.1 Before analysis of a new sample, flush the injection
loop with wash solution.
12.2.2 Perform a blank analysis by flushing the injector and
injecting heptane and ensure that the MDA concentration is
<0.1 mg ⁄L.
12.2.3 Inject a filtered jet fuel sample, and measure the peak
area and determine its concentration using the calibration
regression line. Check that the sample chromatogram is ap-
proximately similar to the chromatogram Fig. 5.
12.2.4 At least after every five aviation fuel samples, inject
the same volume of heptane as a blank and verify that MDA
carryover is <0.1 mg ⁄L. If necessary, increase the frequency of
blanks and washes.
FIG. 4 MDA Capillary-HPLC Calibration using Kerosene
12.2.5 At least every ten samples, analyze the Calibration
Check Standard. The Calibration Check Standard result should
be within 5 % of the expected concentration.
using the equation in Fig. 4 for the given slope and y-intercept
the calculated value is 0.14.
13. Quality Control
NOTE 1—The actual specification for the b/m value will be confirmed
during a planned ILS and will be updated if necessary.
13.1 In addition to the performance procedures outlined in
this test method, it is recommended that regular analysis testing
11.4 After injecting the highest concentration calibration
of quality control (QC) sample(s), such as aviation fuel
standard, inject the wash solution (2 μL by 25 μL) and analyze
reference material(s) containing MDA or inhouse generated
heptane blank(s) to ensure that MDA concentration is
MDA in fuel check standard(s) be used (see Practice D6299).
<0.1 mg ⁄L.
13.2 It is recommended to record QC sample test results and
12. Procedure and Analysis of Fuel Samples
confirm the statistical control status for the execution of the
complete test method using control charts (see Practice
12.1 Calibration Check:
12.1.1 After the calibration is completed (Section 11) and D6299).
before analysis of fuel samples, analyze the Calibration Check 13.2.1 Investigate any out-of-control result for root
Standard and measure its MDA peak area. cause(s). Generally, a QC aviation fuel check standard sample
should be analyzed each testing day with routine samples. The
12.1.2 Calculate the concentration of the Calibration Check
Standard in mg/L based on the most recent calibration regres- QC frequency should be increased if many samples are
sion line. The result should match the known value within 5 % routinely analyzed. However, when it is demonstrated that the
relative. If the result differs by more than 5 %, then recalibrate testing is under statistical control, the QC testing frequency
NOTE 1—The sample absorbance wavelength is 315 nm.
FIG. 5 Example Chromatogram of MDA in Aviation Fuel obtained on the Axcend Focus Analyzer
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D8545 − 23
may be reduced. A sufficient supply of QC aviation fuel sample 16.1.1 Interim repeatability (r_interim)—The repeatability
material(s) should be available for the intended period of use standard deviation and associated repeatability limits from a
and must be homogenous and stable under the anticipated single operator for different average property values has been
storage conditions. Such materials stored in sealed ampoules is determined in accordance with Practice D6300 and are listed in
recommended for greater stability and ease of use. Table 3 where r_interim is the value of the difference between
two independent results obtained by the same operator in a
14. Calculation
given laboratory applying the same test method with the same
apparatus under constant operating conditions on identical test
14.1 The aviation fuel sample results are calculated from the
material within short interval
...