ASTM D2710-09(2013)
(Test Method)Standard Test Method for Bromine Index of Petroleum Hydrocarbons by Electrometric Titration
Standard Test Method for Bromine Index of Petroleum Hydrocarbons by Electrometric Titration
SIGNIFICANCE AND USE
5.1 This test method provides a measure of trace amounts of unsaturated hydrocarbons in petroleum distillates boiling up to 288°C (550°F). An estimate of the quantity of these materials is useful in assessing the suitability of the lighter fractions for use as reaction solvents.
SCOPE
1.1 This test method covers the determination of the amount of bromine-reactive material in petroleum hydrocarbons and is thus a measure of trace amounts of unsaturates in these materials. It is applicable to materials having bromine indexes below 1000.
1.2 This test method is applicable only to essentially olefin-free hydrocarbons or mixtures that are substantially free from material lighter than isobutane and have a distillation end point under 288°C (550°F). Note 1—This procedure has been cooperatively tested on materials with bromine indexes in the range from 100 to 1000. These materials include petroleum distillates such as straight-run and hydrocracked naphtha, reformer feed, kerosine, and aviation turbine fuel.Note 2—Materials with bromine index greater than 1000 should be tested for bromine number using Test Method D1159/IP 130. Note 3—Bromine index of industrial aromatic hydrocarbons should be determined using Test Method D1492 or D5776. The subcommittee is currently examining ways to achieve more consistent end point values.
1.3 The values stated in SI units are to be regarded as standard. The values stated in inch-pound units are for information only.
1.4 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.
General Information
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Standards Content (Sample)
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Designation: D2710 − 09 (Reapproved 2013)
Designation: 299/92 (98)
Standard Test Method for
Bromine Index of Petroleum Hydrocarbons by Electrometric
Titration
This standard is issued under the fixed designation D2710; 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 2. Referenced Documents
1.1 This test method covers the determination of the amount 2.1 ASTM Standards:
of bromine-reactive material in petroleum hydrocarbons and is D1159 Test Method for Bromine Numbers of Petroleum
thus a measure of trace amounts of unsaturates in these Distillates and Commercial Aliphatic Olefins by Electro-
materials. It is applicable to materials having bromine indexes metric Titration
below 1000. D1492 Test Method for Bromine Index of Aromatic Hydro-
carbons by Coulometric Titration
1.2 This test method is applicable only to essentially olefin-
D5776 Test Method for Bromine Index of Aromatic Hydro-
free hydrocarbons or mixtures that are substantially free from
carbons by Electrometric Titration
material lighter than isobutane and have a distillation end point
under 288°C (550°F).
3. Terminology
NOTE 1—This procedure has been cooperatively tested on materials
with bromine indexes in the range from 100 to 1000. These materials
3.1 Definitions:
include petroleum distillates such as straight-run and hydrocracked
3.1.1 bromine index, n—the number of milligrams of bro-
naphtha, reformer feed, kerosine, and aviation turbine fuel.
mine that will react with 100 g of sample under the conditions
NOTE 2—Materials with bromine index greater than 1000 should be
of the test.
tested for bromine number using Test Method D1159/IP 130.
NOTE 3—Bromine index of industrial aromatic hydrocarbons should be
determined using Test Method D1492 or D5776. The subcommittee is
4. Summary of Test Method
currently examining ways to achieve more consistent end point values.
4.1 A known mass of the sample dissolved in a specified
1.3 The values stated in SI units are to be regarded as
solvent is titrated with standard bromide-bromate solution.The
standard. The values stated in inch-pound units are for infor-
end point is indicated by a dead stop electrometric titration
mation only.
apparatus when the presence of free bromine causes a sudden
1.4 This standard does not purport to address all of the
change in the electrical conductivity of the system.
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
5. Significance and Use
priate safety and health practices and determine the applica-
5.1 This test method provides a measure of trace amounts of
bility of regulatory limitations prior to use.
unsaturated hydrocarbons in petroleum distillates boiling up to
288°C (550°F). An estimate of the quantity of these materials
is useful in assessing the suitability of the lighter fractions for
use as reaction solvents.
6. Apparatus
6.1 Electrometric End Point Titration Apparatus—Any ap-
paratus designed to perform titrations to pre-set end points (see
Note 4) may be used in conjunction with a high-resistance
This test method is under the jurisdiction of ASTM Committee D02 on
Petroleum Products, Liquid Fuels, and Lubricantsand is the direct responsibility of
Subcommittee D02.06 on Analysis of Liquid Fuels and Lubricants.
Current edition approved Oct. 1, 2013. Published October 2013. Originally
approved in 1968. Last previous edition approved in 2009 as D2710 – 09. DOI: For referenced ASTM standards, visit the ASTM website, www.astm.org, or
10.1520/D2710-09R13. contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
In the IP, this test method is under the jurisdiction of the Standardization Standards volume information, refer to the standard’s Document Summary page on
Committee. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D2710 − 09 (2013)
polarizing current supply capable of maintaining approxi- manner as to rinse the stopper, lip, and walls of the flask, and
mately 0.8 V across two platinum electrodes and with a titrate promptly with the standard sodium thiosulfate
sensitivity such that a voltage change of approximately 50 mV (Na S O ) solution. Near the end of the titration, add 1 mL of
2 2 3
at these electrodes is sufficient to indicate the end point. Other starch indicator solution and titrate slowly to the disappearance
types of commercially available electric titrimeters, including of the blue color. Calculate the normality of the bromide-
certain pH meters, have also been found to be suitable. bromate solution as follows:
NOTE 4—Pre-set end point indicated with polarized electrodes provides
N 5 A N /A (1)
1 2 2 1
a detection technique similar to the dead stop technique specified in
previous versions of this test method.
where:
6.2 Titration Vessel—A jacketed glass vessel of approxi-
N = normality of the bromide-bromate solution,
mately 150-mL capacity of such a form that can be conve-
A = millilitres of the bromide-bromate solution,
niently maintained at 0 to 5°C (32 to 41°F).Apair of platinum N = normality of the Na S O solution, and
2 2 2 3
electrodes spaced not more than 5 mm apart shall be mounted A = millilitres of the Na S O solution required for titration
2 2 2 3
of the bromide-bromate solution.
to extend well below the liquid level. Stirring shall be by a
mechanical or electromagnetic stirrer and shall be rapid, but
7.3.2 Potassium Iodide Solution (150 g/L)—Dissolve 150 g
not so vigorous as to draw air bubbles down to the electrodes.
of KI in water and dilute to 1 L.
6.3 Burets, 10 and 50-mL capacity.
7.3.3 Sodium Thiosulfate, Standard Solution (0.05 N)—
Dissolve 12.5 g of sodium thiosulfate pentahydrate (Na S O ·
2 2 3
6.4 Iodine Number Flasks, glass-stoppered, 500-mL capac-
5H O) in water and add 0.01 g of sodium carbonate (Na CO )
2 2 3
ity.
to stabilize the solution. Dilute to 1 L and mix thoroughly by
shaking. Standardize by any accepted procedure that deter-
7. Reagents
mines the normality with an error not greater than 60.0002.
7.1 Purity of Reagents—Reagent grade chemicals shall be
Restandardizeatintervalsfrequentenoughtodetectchangesof
used in all tests. Unless otherwise indicated, it is intended that
0.0005 in normality.
all reagents shall conform to the specifications of theAmerican
3 7.3.4 Starch Indicator Solution—Mix5gof soluble starch
Chemical Society where such specifications are available.
with approximately 3 to 5 mL of water. If desired, add about
Other grades may be used, providing it is first ascertained that
0.65 g salicylic acid as preservative.Add the slurry to 500 mL
the reagent is of sufficiently high purity to permit its use
of boiling water and continue boiling for 5 to 10 min.Allow to
without lessening the accuracy of the determination.
cool and decant the supernatant liquid into glass bottles and
7.2 Purity of Water—Unless otherwise indicated, references
seal well. Starch solutions (some preserved with salicylic acid)
to water shall be understood to mean distilled water, or water
are also commercially available and may be substituted.
of equivalent purity.
7.3.5 Sulfuric Acid (1+5)—Carefully add 1 volume of
7.3 Preparation and Standardization : concentrated sulfuric acid (H SO , sp gr 1.84) to 5 volumes of
2 4
water and thoroughly mix. (Warning —Poison. Corrosive.
7.3.1 Bromide-Bromate Standard Solution (0.05 N)—
Dissolve 5.1 g of potassium bromide (KBr) and 1.4 g potas- Strong oxidizer. Contact with organic material may cause fire.
May be fatal if swallowed.)
sium bromate (KBrO ) in water and dilute to 1 L. Standardize
to four significant figures as follows: Place 50 mL of glacial 7.3.6 Titration Solvent—Prepare 1 L of titration solvent by
acetic acid (Warning —Poison. Combustible. May be fatal if mixing the following volumes of materials: 714 mL of glacial
swallowed. Causes severe burns. Harmful if inhaled) and 1 mL acetic acid, 134 mL of 1,1,1-trichloroethane or
of concentrated hydrochloric acid (HCl, sp gr 1.19) dichloromethane, 134 mL of methanol, and 18 mL of H SO
2 4
(Warning—Poison. Corrosive. May be fatal if swallowed. (1+5) (see 7.3.5).
Liquid and vapor cause severe
...
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