ASTM D1840-96

NOTICE: This standard has either been superseded and replaced by a new version or
withdrawn.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: D 1840 – 96 An American National Standard
AMERICAN SOCIETY FOR TESTING AND MATERIALS
100 Barr Harbor Dr., West Conshohocken, PA 19428
Reprinted from the Annual Book of ASTM Standards. Copyright ASTM
Standard Test Method for
Naphthalene Hydrocarbons in Aviation Turbine Fuels by
1
Ultraviolet Spectrophotometry
This standard is issued under the fixed designation D 1840; 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 (e) indicates an editorial change since the last revision or reapproval.
This test method has been adopted for use by government agencies to replace Method 3704 of Federal Test Method Standard No. 791b.
1. Scope transported in a beam of radiant energy.
3.2 Definitions of Terms Specific to This Standard:
1.1 This test method covers the determination, by ultraviolet
3.2.1 transmittance, T, n—the molecular property of a
spectrophotometry, of the total concentration of naphthalene,
substance that determines its transportability of radiant power
acenaphthene, and alkylated derivatives of these hydrocarbons
expressed by
in straight-run jet fuels containing not more than 5 % of such
components and having end points below 315°C (600°F). This T 5 P/P (1)
o
test method determines the maximum amount of naphthalenes
where:
that could be present.
P 5 radiant power passing through the sample, and
1.2 The values stated in SI units are to be regarded as the
P 5 radiant power incident upon the sample.
o
standard. The values stated in inch-pound units are for infor-
3.2.2 absorbance, A, n—the molecular property of a
mation only.
substance that determines its ability to take up radiant power,
1.3 This standard does not purport to address all of the
expressed by
safety concerns, if any, associated with its use. It is the
A 5 log ~1/T!52log T (2)
responsibility of the user of this standard to establish appro-
10 10
priate safety and health practices and determine the applica-
where:
bility of regulatory limitations prior to use. For specific
T 5 transmittance as defined in 3.2.1.
precautionary statements see 8.1 and 8.2.
3.2.2.1 Discussion—It may be necessary to correct the
observed transmittance (indicated by the spectrophotometer)
2. Referenced Documents
by compensating for reflectance losses, solvent absorption
2.1 ASTM Standards:
losses, or refraction effects.
2
E 131 Terminology Relating to Molecular Spectroscopy
3.2.3 absorptivity, a, n—the specific property of a substance
E 169 Practices for General Techniques of Ultraviolet-
2 to absorb radiant power per unit sample concentration and
Visible Quantitative Analysis
pathlength, expressed by
E 275 Practice for Describing and Measuring Performance
a 5 A/bc (3)
of Ultraviolet, Visible, and Near Infrared Spectrophotom-
2
eters
where:
A 5 absorbance defined in 3.2.2,
3. Terminology
b 5 sample cell path length, and
3.1 Definitions:
c 5 quantity of absorbing substance contained in a unit
3.1.1 Definitions of terms and symbols relating to absorp-
volume of solvent.
tion spectroscopy in this test method shall conform to Termi-
3.2.3.1 Discussion—Quantitative ultraviolet analyses are
nology E 131. Terms of particular significance are the follow-
based upon the absorption law, known as Beer’s law. The law
ing:
states that the absorbance of a homogeneous sample containing
3.1.1.1 radiant energy, n—energy transmitted as electro-
an absorbing substance is directly proportional to the
magnetic waves.
concentration of the absorbing substance at a single
3.1.1.2 radiant power, P, n—the rate at which energy is
wavelength, expressed by
A 5 abc (4)
1
This test method is under the jurisdiction of ASTM Committee D-2 on
where:
Petroleum Products and Lubricants and is the direct responsibility of Subcommittee
D02.04 on Hydrocarbon Analysis.
A 5 absorbance as defined in 3.2.2,
Current edition approved Apr. 10, 1996. Published June 1996. Originally
a 5 absorptivity as defined in 3.2.3,
published as D 1840 – 61 T. Last previous edition D 1840 – 92.
b 5 sample cell pathlength, and
2
Annual Book of ASTM Standards, Vol 03.06.
1

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D 1840
samples whose absorbance has been established by a
c 5 quantity of absorbing substance contained in a unit
standardizing laboratory.
volume of solvent.
7.2 It shall be initially and thereafter periodically
3.2.4 sample cell pathlength, b, n—the distance, in
demonstrated that an instrument can be operated in a manner to
centimetres, measured in the direction of propagation of the
give test results equivalent to those described in 7.1.
beam of radiant energy, between the surfaces of the specimen
on which the radiant energy is incident and the surface of the
NOTE 1—Fo
...