ASTM D2710-99(2004)e1
(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
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 288oC (550oF).
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.
1.1 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.
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 D 1159/IP 130.
Note 3 -- Bromine index of industrial aromatic hydrocarbons should be determined using Test Method D 1492 or D 5776.
General Information
Relations
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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
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Designation:D2710–99 (Reapproved 2004)
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.
´ NOTE—Warning notes were editorially moved into the standard text in May 2004.
1. Scope D1159 Test Method for Bromine Numbers of Petroleum
Distillates and Commercial Aliphatic Olefins by Electro-
1.1 This test method covers the determination of the amount
metric Titration
of bromine-reactive material in petroleum hydrocarbons and is
D1492 Test Method for Bromine Index ofAromatic Hydro-
thus a measure of trace amounts of unsaturates in these
carbons by Coulometric Titration
materials. It is applicable to materials having bromine indexes
D5776 Test Method for Bromine Index ofAromatic Hydro-
below 1000.
carbons by Electrometric Titration
1.2 This test method is applicable only to essentially olefin-
free hydrocarbons or mixtures that are substantially free from
3. Terminology
material lighter than isobutane and have a distillation end point
3.1 Definition:
under 288°C (550°F).
3.1.1 bromine index—the number of milligrams of bromine
1.3 The values stated in SI units are to be regarded as
that will react with 100 g of sample under the conditions of the
standard. The values stated in inch-pound units are for infor-
test.
mation only.
1.4 This standard does not purport to address all of the
4. Summary of Test Method
safety concerns, if any, associated with its use. It is the
4.1 A known mass of the sample dissolved in a specified
responsibility of the user of this standard to establish appro-
solvent is titrated with standard bromide-bromate solution.The
priate safety and health practices and determine the applica-
end point is indicated by a dead stop electrometric titration
bility of regulatory limitations prior to use.
apparatus when the presence of free bromine causes a sudden
NOTE 1—This procedure has been cooperatively tested on materials
change in the electrical conductivity of the system.
with bromine indexes in the range from 100 to 1000. These materials
include petroleum distillates such as straight-run and hydrocracked
5. Significance and Use
naphtha, reformer feed, kerosine, and aviation turbine fuel.
5.1 This test method provides a measure of trace amounts of
NOTE 2—Materials with bromine index greater than 1000 should be
unsaturated hydrocarbons in petroleum distillates boiling up to
tested for bromine number using Test Method D1159/IP 130.
288°C (550°F). An estimate of the quantity of these materials
NOTE 3—Bromine index of industrial aromatic hydrocarbons should be
determined using Test Method D1492 or D5776.
is useful in assessing the suitability of the lighter fractions for
use as reaction solvents.
2. Referenced Documents
6. Apparatus
2.1 ASTM Standards:
6.1 Electrometric End Point Titration Apparatus—Any ap-
paratus designed to perform titrations to pre-set end points (see
This test method is under the jurisdiction of ASTM Committee D02 on
Note 4) may be used in conjunction with a high-resistance
Petroleum Products and Lubricants and is the direct responsibility of Subcommittee
D02.04 on Hydrocarbon Analysis.
polarizing current supply capable of maintaining approxi-
Current edition approved May 1, 2004. Published May 2004. Originally
mately 0.8 V across two platinum electrodes and with a
approved in 1968. Last previous edition approved in 1999 as D2710 – 99.
sensitivity such that a voltage change of approximately 50 mV
In the IP, this test method is under the jurisdiction of the Standardization
at these electrodes is sufficient to indicate the end point. Other
Committee. DOI: 10.1520/D2710-99R04E01.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
types of commercially available electric titrimeters, including
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
certain pH meters, have also been found to be suitable.
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
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D2710–99 (2004)
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 titra-
2 2 2 3
to extend well below the liquid level. Stirring shall be by a
tion of the bromide-bromate solution.
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)—
6.4 Iodine Number Flasks, glass-stoppered, 500-mL capac-
Dissolve 12.5 g of sodium thiosulfate pentahydrate (Na S O ·
2 2 3
ity.
5H O) in water and add 0.01 g of sodium carbonate (Na CO )
2 2 3
to stabilize the solution. Dilute to 1 L and mix thoroughly by
7. Reagents
shaking. Standardize by any accepted procedure that deter-
7.1 Purity of Reagents—Reagent grade chemicals shall be mines the normality with an error not greater than 60.0002.
used in all tests. Unless otherwise indicated, it is intended that
Restandardize at intervals frequent enough to detect changes of
all reagents shall conform to the specifications of theAmerican 0.0005 in normality.
Chemical Society where such specifications are available.
7.3.4 Starch Indicator Solution—Mix5gof soluble starch
Other grades may be used, providing it is first ascertained that
with approximately 3 to 5 mL of water. If desired, add about
the reagent is of sufficiently high purity to permit its use
0.65 g salicylic acid as preservative.Add the slurry to 500 mL
without lessening the accuracy of the determination.
of boiling water and continue boiling for 5 to 10 min.Allow to
7.2 Purity of Water—Unless otherwise indicated, references
cool and decant the supernatant liquid into glass bottles and
to water shall be understood to mean distilled water, or water
seal well. Starch solutions (some preserved with salicylic acid)
of equivalent purity.
are also commercially available and may be substituted.
7.3 Preparation and Standardization:
7.3.5 Sulfuric Acid (1+5)—Carefully add 1 volume of
7.3.1 Bromide-Bromate Standard Solution (0.05 N)—
concentrated sulfuric acid (H SO , sp gr 1.84) to 5 volumes of
2 4
Dissolve 5.1 g of potassium bromide (KBr) and 1.4 g potas-
water and thoroughly mix. (Warning—Poison. Corrosive.
sium bromate (KBrO ) in water and dilute to 1 L. Standardize
Strong oxidizer. Contact with organic material may cause fire.
to four significant figures as follows: Place 50 mL of glacial
May be fatal if swallowed.)
acetic acid (Warning—Poison. Combustible. May be fatal if
7.3.6 Titration Solvent—Prepare 1 L of titration solvent by
swallowed. Causes severe burns. Harmful if inhaled) and 1 mL
mixing the following volumes of materials: 714 mL of glacial
of concentrated hydrochloric acid (HCl, sp gr 1.19)
acetic acid, 134 mL of 1,1,1-trichloroethane or dichlo-
(Warning—Poison. Corrosive. May be fatal if swallowed.
romethane, 134 mL of methanol, and 18 mL of H SO (1+5)
2 4
Liquid and vapor cause severe burns. Harmful if inhaled.) in a
(see 7.3.5).
500-mL iodine number flask. Chill the solution in an ice bath
7.4 Solvents:
for approximately 10 min, and with constant swirling of the
7.4.1 Acetic Acid, glacial. (Warning—Poison. Combus-
flask, add from a 50-mLburet 40 to 45 mLof bromide-bromate
tible. May be fatal if swallowed. Causes severe burns. Harmful
solution, estimated to the near
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