ASTM D1840-07(2013)

Standard Test Method for Naphthalene Hydrocarbons in Aviation Turbine Fuels by Ultraviolet Spectrophotometry

SIGNIFICANCE AND USE
5.1 This test method for naphthalene hydrocarbons is one of a group of tests used to assess the combustion characteristics of aviation turbine fuels of the kerosene boiling range. The naphthalene hydrocarbon content is determined because naphthalenes, when burned, tend to have a relatively larger contribution to a sooty flame, smoke, and thermal radiation than single ring aromatics.
SCOPE
1.1 This test method covers the determination, by ultraviolet spectrophotometry, of the total concentration of naphthalene, acenaphthene, and alkylated derivatives of these hydrocarbons in jet fuels. This test method is designed to analyze fuels containing not more than 5 % of such components and having end points below 315°C (600°F); however, the range of concentrations used in the interlaboratory test programs which established the precision statements for this test method were 0.03 to 4.25 volume % for Procedure A, and 0.08 to 5.6 volume % for Procedure B. This test method determines the maximum amount of naphthalenes that could be present.  
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.3 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 and health practices and determine the applicability of regulatory limitations prior to use. For specific warning statements, see 8.1 and 8.2.

General Information

• Status: Historical
• Publication Date: 30-Sep-2013
• ICS: 75.160.20 - Liquid fuels
• Technical Committee: D02 - Petroleum Products, Liquid Fuels, and Lubricants
• Drafting Committee: D02.04.0F - Absorption Spectroscopic Methods

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: D1840 − 07 (Reapproved 2013)
Standard Test Method for
Naphthalene Hydrocarbons in Aviation Turbine Fuels by
Ultraviolet Spectrophotometry
This standard is issued under the fixed designation D1840; 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.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope 3.1.1 Definitions of terms and symbols relating to absorp-
tion spectroscopy in this test method shall conform to Termi-
1.1 Thistestmethodcoversthedetermination,byultraviolet
nology E131. Terms of particular significance are the follow-
spectrophotometry, of the total concentration of naphthalene,
ing:
acenaphthene, and alkylated derivatives of these hydrocarbons
3.1.2 radiant energy, n—energy transmitted as electromag-
in jet fuels. This test method is designed to analyze fuels
netic waves.
containing not more than 5 % of such components and having
end points below 315°C (600°F); however, the range of
3.1.3 radiant power, P, n—rate at which energy is trans-
concentrations used in the interlaboratory test programs which
ported in a beam of radiant energy.
established the precision statements for this test method were
3.2 Definitions of Terms Specific to This Standard:
0.03to4.25volume%forProcedureA,and0.08to5.6volume
3.2.1 absorbance, A, n—the molecular property of a sub-
% for Procedure B. This test method determines the maximum
stance that determines its ability to take up radiant power,
amount of naphthalenes that could be present.
expressed by
1.2 The values stated in SI units are to be regarded as
A 5 log 1/T 52log T (1)
~ !
10 10
standard. No other units of measurement are included in this
standard.
where:
1.3 This standard does not purport to address all of the
T = transmittance as defined in 3.2.5.
safety concerns, if any, associated with its use. It is the
3.2.1.1 Discussion—It may be necessary to correct the
responsibility of the user of this standard to establish appro-
observed transmittance (indicated by the spectrophotometer)
priate safety and health practices and determine the applica-
by compensating for reflectance losses, solvent absorption
bility of regulatory limitations prior to use. For specific
losses, or refraction effects.
warning statements, see 8.1 and 8.2.
3.2.2 absorptivity, a, n—the specific property of a substance
2. Referenced Documents
to absorb radiant power per unit sample concentration and path
2.1 ASTM Standards:
length, expressed by
E131 Terminology Relating to Molecular Spectroscopy
a 5 A/bc (2)
E169 PracticesforGeneralTechniquesofUltraviolet-Visible
Quantitative Analysis
where:
E275 Practice for Describing and Measuring Performance of
A = absorbance defined in 3.2.1,
Ultraviolet and Visible Spectrophotometers
b = sample cell path length, and
c = quantity of absorbing substance contained in a unit
3. Terminology
volume of solvent.
3.1 Definitions:
3.2.2.1 Discussion—Quantitative ultraviolet analyses are
This test method is under the jurisdiction of ASTM Committee D02 on
based upon the absorption law, known as Beer’s law. The law
Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of
statesthattheabsorbanceofahomogeneoussamplecontaining
Subcommittee D02.04.0F on Absorption Spectroscopic Methods.
an absorbing substance is directly proportional to the concen-
Current edition approved Oct. 1, 2013. Published October 2013. Originally
approved in 1961. Last previous edition approved in 2007 as D1840 – 07. DOI:
tration of the absorbing substance at a single wavelength,
10.1520/D1840-07R13.
expressed by
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
A 5 abc (3)
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. where:
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D1840 − 07 (2013)
7. Apparatus
A = absorbance as defined in 3.2.1,
a = absorptivity as defined in 3.2.2,
7.1 Spectrophotometer, equipped to measure the absorbance
b = sample cell path length, and
ofsolutionsinthespectralregion240to300nmwithaspectral
c = quantity of absorbing substance contained in a unit
slit width of 1 nm or less. Wavelength measurements shall be
volume of solvent.
repeatable and known to be accurate within 0.1 nm or less as
3.2.3 concentration, c, n—the quantity of naphthalene hy- measured by mercury emission line at 253.65 nm or the
drocarbons in grams per litre of isooctane. absorptionspectrumofeitherholmiumoxideglassat287.5nm
or holmium oxide solution at 287.1 nm.At the 0.4 absorbance
3.2.4 sample cell path length, b, n—the distance, in
level in the spectral region between 240 and 300 nm, absor-
centimetres, measured in the direction of propagation of the
bance measurements shall be repeatable within 60.5 % or
beam of radiant energy, between the surfaces of the specimen
better. In the absorbance range encompassing 0.2 to 0.8, the
on which the radiant energy is incident and the surface of the
photometric accuracy shall not differ by more than 60.5 % of
specimen from which it is emergent.
samples whose absorbance has been established by a standard-
3.2.4.1 Discussion—This distance does not include the
izing laboratory.
thickness of the cell in which the specimen is contained.
7.1.1 Discussion—Many manufacturers provide secondary
3.2.5 transmittance, T, n—the molecular property of a sub-
standards, traceable to NIST primary standards, for checking
stance that determines its transportability of radiant power
the wavelength accuracy and photometric accuracy of spectro-
expressed by
photometers. These materials may be used to verify spectro-
T 5 P/P (4)
o photometer performance provided that they have been recali-
brated periodically as recommended by the manufacturer.
where:
7.2 It shall be initially and thereafter periodically demon-
P = radiant power passing through the sample, and
strated that an instrument can be operated in a manner to give
P = radiant power incident upon the sample.
o
test results equivalent to those described in 7.1.
4. Summary of Test Method
NOTE 1—For recommended methods of testing spectrophotometers to
be used in this test method, refer to Practice E275. Other preferred
4.1 The total concentration of naphthalenes in jet fuels is
alternatives to those in 7.1 are potassium dichromate in perchloric acid
determined by measurement of the absorbance at 285 nm of a
(NIST SRM 935 series as described in Practice E275) for photometric
solution of the fuel at known concentration.
accuracy and a 20 mg/Lhigh (>99 %) purity naphthalene in spectroscopic
grade isooctaneforwavelengthaccuracy.Thelatterhasaminormaximum
5. Significance and Use
at 285.7 nm. The naphthalene solution shall not be used for photometric
accuracy.
5.1 This test method for naphthalene hydrocarbons is one of
7.3 Vitreous Silica Cells,two,havingpathlengthsof1.00 6
agroupoftestsusedtoassessthecombustioncharacteristicsof
0.005 cm.
aviation turbine fuels of the kerosene boiling range. The
naphthalene hydrocarbon content is determined because 7.4 Pipets, Class A.
naphthalenes, when burned, tend to have a relatively larger
7.5 Lens Paper.
contribution to a sooty flame, smoke, and thermal radiation
7.6 Balance, capable of taring or weighing 100 g to the
than single ring aromatics.
nearest 0.0001 g. The balance shall be accurate to 60.0002 g
at a 100-g load.
6. Interferences
8. Solvents
6.1 Interferences add to the apparent naphthalene content.
Phenanthrenes, dibenzothiophenes, biphenyls,
8.1 Spectroscopic 2,2,4 Trimethylpentane (Isooctane).
benzothiophenes, and anthracenes interfere if present. The end
(Warning—Isooctane is extremely flammable, harmful if in-
point limitation of 315°C will minimize this interference
haled.)
except for benzothiophenes and biphenyls. The contribution to
NOTE 2—Spectroscopic-grade isooctane is available commercially.
measured naphthalene content by the presence of 1 % of such
Technical-grade isooctane is a satisfactory base stock for the preparation
interfering compounds can be estimated from Table 1.
of spectroscopic solvent.Allow about 4 or 5 Lof this material to percolate
through a column of activated silica gel (74 µm) 50.8 to 76.2 mm in
6.2 Saturated hydrocarbons, olefins, thiophenes, and alkyl
diameter and 0.6 to 0.9 m in depth. Collect only the portion of the solvent
or cycloalkyl derivatives of benzene will not interfere.
that has a transmission compared to distilled water greater than 90 % over
the entire spectral range from 240 to 300 nm. Store in scrupulously clean
glass-stoppered bottles and always keep covered. In general it will be best
to use a fresh portion of silica gel in preparing a new batch of solvent.
TABLE 1 Interfering Compounds
Howeverthegelcanbereactivatedbypouring500mLofacetonethrough
Error in Percentage of
the column, draining, drying by suction, and heating the gel in thin layers
Type of Interfering Compound Naphthalenes Caused by 1 %
in an oven at 400°C until white color is restored. Activated silica gel is
Interfering Compound
stored in closed containers.
Phenanthrenes 2
Dibenzothiophenes 2 8.2 Solvents for Cleaning Cells—Acetone or ethyl alcohol
Biphenyls 1
(Warning—Acetone and ethyl alcohol are extremely flam-
Benzothiophenes 0.6
mable and can be harmful if inhaled), with residue after
Anthracenes 0.1
evaporation no greater than 10 mg/kg.
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