ASTM D6313-99
(Test Method)Test Method for Total Sulfur in Aromatic Compounds by Hydrogenolysis and Sulfur Specific Difference Photometry (Withdrawn 2008)
Test Method for Total Sulfur in Aromatic Compounds by Hydrogenolysis and Sulfur Specific Difference Photometry (Withdrawn 2008)
SIGNIFICANCE AND USE
Sulfur can be a catalyst poison in the aromatic chemical manufacturing process. This test method can be used to monitor the amount of sulfur in aromatic hydrocarbons. This test method may also be used as a quality control tool and in setting specifications for sulfur determination in finished products.
SCOPE
1.1 This test method covers the determination of sulfur in aromatic hydrocarbons, their derivatives and related chemical having typical sulfur concentrations from 0.005 to 10 mg/kg.
1.2 This test method may be extended to higher concentrations by dilution.
1.3 This test method is applicable to aromatic hydrocarbons such as benzene, toluene, cumene, p-xylene, o-xylene, cyclohexane, phenol, cresols, xylenols, and other aromatic or oxygenated aromatic compounds.
1.4 The following applies to all specified limits in this test method: for purposes of determining conformance with this standard, an observed value or a calculated value shall be rounded off to the nearest unit in the last right-hand digit used for expressing the specification limit in accordance with the rounding-off method of Practice E 29.
1.5 This standard does not purport to address all of the safety problems, 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. specific precautionary statements are given in 7./5, 76. 8, 11.4.
WITHDRAWN RATIONALE
This test method covers the determination of sulfur in aromatic hydrocarbons, their derivatives and related chemicals having typical sulfur concentrations from 0.005 to 10 mg/kg.
Formerly under the jurisdiction of Committee D16 on Aromatic Hydrocarbons and Related Chemicals, this test method was withdrawn in August 2008 in accordance with section 10.5.3.1 of the Regulations Governing ASTM Technical Committees, which requires that standards shall be updated by the end of the eighth year since the last approval date.
General Information
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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: D 6313 – 99
Test Method for
Total Sulfur in Aromatic Compounds by Hydrogenolysis and
Sulfur Specific Difference Photometry
This standard is issued under the fixed designation D 6313; 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.
1. Scope Determine Conformance with Specifications
2.2 Other Documents:
1.1 This test method covers the determination of sulfur in
OSHA Regulations, 29 CFR, paragraphs 1910.1000 and
aromatic hydrocarbons, their derivatives and related chemicals
1910.12000
having typical sulfur concentrations from 0.005 to 10 mg/kg.
1.2 This test method may be extended to higher concentra-
3. Terminology
tions by dilution.
3.1 Definitions:
1.3 This test method is applicable to aromatic hydrocarbons
3.1.1 difference photometry, n—an analytical method where
such as benzene, toluene, cumene, p-xylene, o-xylene, cyclo-
a photometric property of a colorimetric reactant (such as
hexane, phenol, cresols, xylenols, and other aromatic or
reflectivity) is first measured as a baseline reading, the reactant
oxygenated aromatic compounds.
exposed to the material in question, then a second reading
1.4 The following applies to all specified limits in this test
taken.
method: for purposes of determining conformance with this
3.1.1.1 Discussion—The difference between the post expo-
standard, an observed value or a calculated value shall be
sure reading and the baseline reading constitute the measure-
rounded off to the nearest unit in the last right-hand digit used
ment of the reaction between the material in question and the
for expressing the specification limit in accordance with the
reactant,thatis,ifthereactantchangesitsphotometricproperty
rounding-off method of Practice E 29.
proportionally to the concentration of the material in question,
1.5 This standard does not purport to address all of the
the method could be used to measure concentration.
safety concerns, if any, associated with its use. It is the
3.1.2 oxyhydropyrolysis, v—The act of first burning a ma-
responsibility of the user of this standard to establish appro-
terial within an inner chamber in a pyrolysis furnace to change
priate safety and health practices and determine the applica-
that material to combustion products, and then to release those
bility of regulatory limitations prior to use. Specific precau-
products into a hydrogen rich atmosphere to then reduce those
tionary statements are given in 7.5, 7.6, 8, 11.4.
combustion products.
2. Referenced Documents 3.2 See Terminology D 4790 for definitions of other terms
used in this test method.
2.1 ASTM Standards:
D 1193 Specification for Reagent Water
4. Summary of Test Method
D 3437 Practice for Sampling and Handling Liquid Cyclic
3 4.1 Reductive Configuration—A specific amount of sample
Products
is injected at a uniform rate into an air stream and introduced
D 3852 Practice for Sampling and Handling Phenol and
3 into a sample dispersing mechanism where the liquid sample is
Cresylic Acid
evaporated and thoroughly mixed with the hydrogen. This
D 4052 Test Method for Density and Relative Density of
4 mixture is then introduced into a pyrolysis furnace. Within this
Liquids for Digital Density Meter
apparatus the sample is pyrolyzed at temperatures of 1200° to
D 4790 Terminology of Aromatic Hydrocarbons and Re-
1300°C and in the presence of excess hydrogen. The sulfur
lated Chemicals
compounds are broken down and reduced to H S. Analysis is
E 29 Practice for Using Significant Digits in Test Data to
by difference photometry of the colorimetric reaction of H S
with lead acetate.
4.2 OxyhydroPyrolysis Configuration—A specific amount
This test method is under the jurisdiction of ASTM Committee D16 on
Aromatic Hydrocarbons and Related Chemicals and is the direct responsibility of of sample is injected at a uniform rate into an air stream and
Subcommittee D016.04 on Instrumental Analysis.
Current edition approved April 10, 1999. Published June 1999. Originally
published as D 6313 – 98. Last previous edition D 6313 – 98.
2 5
Annual Book of ASTM Standards, Vol 11.01. Annual Book of ASTM Standards, Vol 14.02.
3 6
Annual Book of ASTM Standards, Vol 06.04. AvailablefromSuperintendentofDocuments,U.S.GovernmentPrintingoffice,
Annual Book of ASTM Standards, Vol 05.02. Washington, DC 20402.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D 6313
introduced into a sample dispersing mechanism where the
liquid sample is evaporated and thoroughly mixed with the air.
This mixture is then introduced into a pyrolysis furnace. The
sample flows through an inner tube within the furnace where it
combusts with the oxygen in the air carrier. SO and SO are
2 3
formed from the sulfur compounds in the sample. The sample
then leaves the inner tube within the pyrolyzer and is mixed
with hydrogen within the main reaction tube and is pyrolyzed
at temperatures of 1200° to 1300°C. The SO and SO formed
2 3
within the inner tube are then reduced to H S. Analysis is by
difference photometry of the colorimetric reaction of H S with
lead acetate.
5. Significance and Use
5.1 Sulfur can be a catalyst poison in the aromatic chemical
manufacturing process. This test method can be used to
monitor the amount of sulfur in aromatic hydrocarbons. This
test method may also be used as a quality control tool and in
setting specifications for sulfur determination in finished prod-
ucts.
6. Apparatus
6.1 The apparatus of this test method can be set up in two
different configurations that will be described herein as the
“reductive pyrolysis” configuration, and the “oxyhydropyroly-
sis” configuration. The oxyhydropyrolysis configuration is a
modification of the reductive pyrolysis configuration, which
minimizes the formation of coke within the pyrolysis furnace
when running aromatic samples. Both setups can be used to
measure sulfur in aromatic compounds as outlined in this test
method.
6.2 Pyrolysis Furnace—A tube furnace that can provide an
adjustable temperature of 900 to 1300° C. An 8-mm or larger
inner diameter is required in the furnace to fit reaction tubes of
sufficient size to pyrolyze the sample.
6.2.1 Oxyhydrogen Furnace Adapter—An apparatus, used
in the oxyhydropyrolysis set up, that fits to the front of the
reaction tube and adds an injection tube that extends partially
FIG. 1 Oxyhydrogen Furnace Adapter Detail
within the main reaction tube to about ⁄2 way into the furnace
(see Fig. 1). The oxidative process occurs in the injection tube,
6.3 Sample Injector—Asyringe drive, autosampler or other
then the combustion products of the sample are injected into
suitable injection system that can inject the sample into the
the flow of hydrogen at the hot zone.
pyrolysisfurnaceatauniforminjectionrateadjustablebetween
6.2.2 Water Removal Apparatus—A device that attaches
1 to 50 µL/min.
close to the outlet of the pyrolysis furnace, used in the
6.4 Sample Dispersion Apparatus —A tube filled with
oxyhydropyrolysis set up to remove excess moisture from the
quartzwoolorotherporousmaterialisplacedattheinletofthe
sample stream. Both membrane counter flow driers or coalesc-
pyrolysis furnace to disperse and mix liquid samples into the
ing filters held at sub-ambient temperatures have been found to
gas carrier before entry into the pyrolyzer. This tube is
be suitable.
surrounded by a small heater for the purpose of controlling the
The sample dispersion apparatus is covered by a patent held by HoustonAtlas
Inc. Interested parties are invited to submit information regarding the identification
of acceptable alternatives to this patented item to the Committee on Standards,
ASTM International Headquarters, 100 Barr Harbor Dr., West Conshohocken, Pa.
19428–2959 USA. Your comments will receive careful consideration at a meeting
of the responsible technical committee, which you may attend.
D 6313
evaporation rate of the liquid sample being injected. Higher 7.6 Instrument Air—Use dry, sulfur free air. Nitrogen/
boilingpointliquidsrequirehigherinlettemperaturestoensure oxygen, or helium/oxygen bottled gas blends containing no
proper evaporation and dispersion. The inlet heater should be more than 30 % oxygen by volume can be used where air
able to be set from room temperature to 350° C. utilitiesarenotavailable.Warning:Donotusepureoxygenas
6.5 Flow System—The flow system to and from the pyroly- a substitute for instrument air.
sis furnace is to be a fluorocarbon, 316 stainless steel, nylon or 7.7 Toluene, sulfur free.
other material inert to H S and other sulfur compounds. Gas 7.8 Thiophene—99 + % purity.
flowshouldbecontrolledbymassfloworpressuredifferential-
8. Hazards
type flow controllers that have a range of 0 to 500 mL/min.
8.1 Consult current OSHA regulations, suppliers Material
6.6 Lead Acetate Difference Photometer—A device that
consists of a paper tape transport mechanism, a sample Safety Date Sheets, and local regulations for all materials used
in this test method.
chamber with a window opening to the surface of lead acetate
treated paper tape, a photometer to read the reflectivity of the
9. Sampling
lead acetate treated tape, and sufficient electronics to control
9.1 Sample the material in accordance with Practice
the transport of tape, to do system timing, to take the
photometric readings, and to control the sample injector. The D 3437.
9.2 Sample phenol and cresylic acid in accordance with
photometer should have sufficient sensitivity to detect 0.005
mg/kg. Practice D 3852.
NOTE 1—The difference photometer works as follows: The paper tape
10. Calibration Standards
is advanced to a new spot. The paper tape is exposed to carrier gas for a
10.1 Prepare a reference standard solution or solutions of
predetermined amount of time (usually 60 s).Azero reading is taken and
strength greater than that expected in the unknown, by first
then sample injection is started and the photometer starts timing its run.
(The run time has been predetermined by trial runs of a specific sample. preparing a stock solution of thiophene in toluene and volu-
The time is set so that all of the sulfur in the sample has had the chance
metrically diluting the stock to prepare low level standards.
to flow through the system and no more change in reflectivity is seen.) A
10.2 Preparation of the Stock Standard Solution:To prepare
final reading is then taken. The zero reading and final reading in
a sulfur standard with a sulfur concentration of 1000 mg/L,
conjunction with a calibration curve is used to determine the sulfur
obtainaclean100-mLvolumetricflask.Pourapproximately90
concentration in the sample. Some computerized difference photometers
mL of toluene (sulfur free), kept at a room temperature of
can generate the calibration curve internally during calibration.
25°C. into the flask.Weigh approximately 0.2625g (250 µL) of
6.7 Recorder—A suitable chart recorder may be used for a
thiophene directly into the flask and record the exact weight
permanentrecordofanalysis.Asuitableprintermaybeusedby
added to a precision of 60.1 mg. Add additional toluene to
computerized photometric analyzers, or data can be read to
make 100.0 mL.
magnetic media for storage or further analysis.
10.3 Calculate the sulfur concentration of the stock solution
as follows:
7. Reagents and Materials
B
7.1 Purity of Chemicals—Reagent grade chemicals shall be
A 5 D (1)
0.1C
used in all tests. Unless otherwise indicated, it is intended that
all reagents shall conform to the specifications of the Commit-
where:
tee onAnalytical Reagents of theAmerican Chemical Society,
A = concentration of sulfur in mg/L,
where such specifications are available. Other grades may be
B = molecular weight of sulfur: 32.6,
used, provided it is first ascertained that the reagent is of
C = molecular weight of thiophene: 84.14,
sufficiently high purity to permit its use without lessening the
D = exact weight of the sulfur compound used in milli-
accuracy of the determination.
grams, and
7.2 Purity of Water—Unless otherwise indicated, reference
0.1 = volume of standard in litres.
to water shall be understood to mean Type IV, reagent grade
10.4 Preparation of Working Standards: The preparation of
water, conforming to Specification D 1193.
working standards is accomplished by volumetric dilution of
7.3 Sensing Tape—Lead-acetate-impregnated analytical-
the stock solution. As an example, to prepare a 1.00-mg/L
quality filter paper shall be used.
standard, dilute 0.10 mL of the 1000-mg/L stock solution into
7.4 Acetic Acid, 5 %—Mix 1 part by volume reagent grade
100 mL of toluene (sulfur free). Note: keep containers closed
glacial acetic acid with 19 parts water to prepare 5 % acetic
as much as possible. Do not open containers of pure sulfur
acid solution.
compounds in the vicinity of low level calibration standards.
7.5 Hydrogen Gas—Use sulfur-free hydrogen of laboratory
NOTE 2—The use of standard samples made to mg/L units have the
grade. Warning: Hydrogen has wide explosive limits when
advantage of delivering a specific number of milligrams of sulfur into the
mixed with air.
analyzer for a specific sample size regardless of the sample compound
used. A standard of one type of compound could be used to calibrate the
analyzer, with an unknown of another type sample compound run. To
Reagent Chemicals, American Chemical Society Specifications, American
determine the sulfur content of the unknown in mg/kg simply divide the
Chemical Society, Washington, DC. For suggestions on the testing of reagents not
mg/L answer by the density (expressed in g/mL) of the unknown sample.
listed by the American Chemical Society, see Analar Standards for Laboratory
Some analyzers complying with this method have provision to enter the
ChemicalsBDHLtd.,Poole,Dorset,U.K.,andthe United States Pharmacopeia and
National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, MD. densities of both the calibration standard and the unknown. In these cases
D 6313
the analyzer will make the appropriate density corrections between the
11.5 Adjust the zero of the difference photometer (and
standard samples and the unknowns being analyzed. The reported mea-
recorder if used) to its desired position with no flow. This
surement units of the answer can be set by the operator.
should be performed with span at maximum. Skip this step if
the difference photometer is computerized and automatically
11. Preparation of Apparatus
sets its own zero l
...
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