ASTM D5808-09a(2014)
(Test Method)Standard Test Method for Determining Chloride in Aromatic Hydrocarbons and Related Chemicals by Microcoulometry
Standard Test Method for Determining Chloride in Aromatic Hydrocarbons and Related Chemicals by Microcoulometry
SIGNIFICANCE AND USE
5.1 Organic as well as inorganic chlorine compounds can prove harmful to equipment and reactions in processes involving hydrocarbons.
5.2 Maximum chloride levels are often specified for process streams and for hydrocarbon products.
5.3 Organic chloride species are potentially damaging to refinery processes. Hydrochloric acid can be produced in hydrotreating or reforming reactors and this acid accumulates in condensing regions of the refinery.
SCOPE
1.1 This test method covers the organic chlorides in aromatic hydrocarbons, their derivatives, and related chemicals.
1.2 This test method is applicable to samples with chloride concentrations from 1 to 25 mg/kg.
1.3 This test method is preferred over Test Method D5194 for products, such as styrene, that are polymerized by the sodium biphenyl reagent.
1.4 In determining the conformance of the test results using this method to applicable specifications, results shall be rounded off in accordance with the rounding-off method of Practice E29.
1.5 Organic chloride values of samples containing inorganic chlorides will be biased high due to partial recovery of inorganic species during combustion. Interference from inorganic species can be reduced by water washing the sample before analysis. This does not apply to water soluble samples.
1.6 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.7 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 hazard statements, see 7.3 and Section 9.
General Information
Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: D5808 − 09a (Reapproved 2014)
Standard Test Method for
Determining Chloride in Aromatic Hydrocarbons and
Related Chemicals by Microcoulometry
This standard is issued under the fixed designation D5808; 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 D1555M TestMethodforCalculationofVolumeandWeight
of Industrial Aromatic Hydrocarbons and Cyclohexane
1.1 This test method covers the organic chlorides in aro-
[Metric]
matic hydrocarbons, their derivatives, and related chemicals.
D3437 Practice for Sampling and Handling Liquid Cyclic
1.2 This test method is applicable to samples with chloride
Products
concentrations from 1 to 25 mg/kg.
D5194 Test Method for Trace Chloride in Liquid Aromatic
1.3 This test method is preferred over Test Method D5194 Hydrocarbons
D6809 Guide for Quality Control and Quality Assurance
for products, such as styrene, that are polymerized by the
sodium biphenyl reagent. Procedures for Aromatic Hydrocarbons and Related Ma-
terials
1.4 In determining the conformance of the test results using
E29 Practice for Using Significant Digits in Test Data to
this method to applicable specifications, results shall be
Determine Conformance with Specifications
rounded off in accordance with the rounding-off method of
E691 Practice for Conducting an Interlaboratory Study to
Practice E29.
Determine the Precision of a Test Method
1.5 Organic chloride values of samples containing inorganic
2.2 Other Document:
chlorides will be biased high due to partial recovery of
OSHA Regulations, 29CFR paragraphs 1910.1000 and
inorganic species during combustion. Interference from inor- 3
1910.1200
ganic species can be reduced by water washing the sample
before analysis. This does not apply to water soluble samples.
3. Terminology
1.6 The values stated in SI units are to be regarded as
3.1 Definitions:
standard. No other units of measurement are included in this
3.1.1 dehydration tube, n—chamber containing concen-
standard.
trated sulfuric acid that scrubs the effluent gases from combus-
1.7 This standard does not purport to address all of the tion to remove water vapor.
safety concerns, if any, associated with its use. It is the
3.1.2 oxidative pyrolysis, n—a process in which a sample is
responsibility of the user of this standard to establish appro-
combusted in an oxygen-rich atmosphere at high temperature
priate safety and health practices and determine the applica-
to break down the components of the sample into elemental
bility of regulatory limitations prior to use. For specific hazard
oxides.
statements, see 7.3 and Section 9.
3.1.3 recovery factor, n—an indication of the efficiency of
the measurement computed by dividing the measured value of
2. Referenced Documents
a standard by its theoretical value.
2.1 ASTM Standards:
3.1.4 reference sensor pair, n—detects changes in silver ion
D1193 Specification for Reagent Water
concentration.
3.1.5 test titration, n—a process that allows the coulometer
to set the endpoint and gain values to be used for sample
This test method is under the jurisdiction of ASTM Committee D16 on
analysis.
Aromatic Hydrocarbons and Related Chemicals is the direct responsibility of
Subcommittee D16.04 on Instrumental Analysis.
3.1.6 titration parameters, n—various instrumental condi-
Current edition approved Feb. 1, 2014. Published February 2014. Originally
tions that can be changed for different types of analysis.
approved in 1995. Last previous edition approved in 2009 as D5808 – 09a. DOI:
10.1520/D5808-09AR14.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM AvailablefromU.S.GovernmentPrintingOfficeSuperintendentofDocuments,
Standards volume information, refer to the standard’s Document Summary page on 732 N. Capitol St., NW, Mail Stop: SDE, Washington, DC 20401, http://
the ASTM website. www.access.gpo.gov.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D5808 − 09a (2014)
3.1.7 working electrode (generator electrode), n—an elec- (Warning—Excessive stirring speed will decouple the stirring
trode consisting of an anode and a cathode separated by a salt bar and cause it to rise in the titration cell and possibly damage
bridge; maintains a constant silver ion concentration. the electrodes. A slight vortex in the cell will be adequate.)
7.4 Microcoulometer, capable of measuring the potential of
4. Summary of Test Method
the sensing-reference electrode pair, and comparing this poten-
4.1 A liquid specimen is injected into a combustion tube
tial with a bias potential, and amplifying the difference to the
maintained at 900°C having a flowing stream of oxygen and
working electrode pair to generate a current. The microcou-
argon carrier gas. Oxidative pyrolysis converts the organic
lometer output voltage signal should be proportional to the
halides to hydrogen halides that then flow into a titration cell
generating current.
where it reacts with silver ions present in the electrolyte. The
7.5 Automatic Boat Drive, having variable stops, such that
silver ion thus consumed is coulometrically replaced and the
the sample boat may be driven into the furnace, and stopped at
total electrical work to replace it is a measure of the organic
various points as it enters the furnace.
halides in the specimen injected (see Annex A1).
7.6 Controller, with connections for the reference, working,
5. Significance and Use
and sensor electrodes. The controller is used for setting of
operating parameters and integration of data.
5.1 Organic as well as inorganic chlorine compounds can
prove harmful to equipment and reactions in processes involv-
7.7 Dehydration Tube, positioned at the end of the pyrolysis
ing hydrocarbons.
tube so that effluent gases are bubbled through a sulfuric acid
solution, and water vapor is subsequently trapped, while all
5.2 Maximum chloride levels are often specified for process
other gases are allowed to flow into the titration cell.
streams and for hydrocarbon products.
7.8 Gas-Tight Sampling Syringe, having a 50 µl capacity,
5.3 Organic chloride species are potentially damaging to
capable of accurately delivering 10 to 40 µl of sample.
refinery processes. Hydrochloric acid can be produced in
hydrotreating or reforming reactors and this acid accumulates
7.9 Quartz Boats.
in condensing regions of the refinery.
8. Reagents and Materials
6. Interferences
8.1 Purity of Reagents—Reagent grade chemicals shall be
6.1 Both nitrogen and sulfur interfere at concentrations
used in all tests. Unless otherwise indicated, it is intended that
greater than approximately 0.1 %.
all reagents shall conform to the specifications of the Commit-
tee onAnalytical Reagents of theAmerican Chemical Society,
NOTE 1—To ensure reliable detectability, all sources of chloride
contamination must be eliminated. where such specifications are available. Other grades may be
used, provided that the reagent is of sufficiently high purity to
6.2 Bromides and iodides, if present, will be calculated as
permit its use without lessening the accuracy of the determi-
chlorides. However, fluorides are not detected by this test
nation.
method.
8.2 Purity of Water—Unless otherwise indicated, references
6.3 Organic chloride values of samples containing inorganic
to water shall be understood to mean reagent water conforming
chlorides will be biased high due to partial recovery of
to Specification D1193, Type II or III.
inorganic species during combustion. Interference from inor-
ganic species can be reduced by water washing the sample
8.3 Acetic Acid—Glacial acetic acid (CH COOH).
before analysis. This does not apply to water soluble samples.
8.4 Argon or Helium, 99.9 % minimum purity required as
carrier gas.
7. Apparatus
8.5 Amidosulfonic Acid (H NSO H), minimum purity 99.3-
2 3
7.1 Pyrolysis Furnace, which can maintain a temperature
100.3 %.
sufficient to pyrolyze the organic matrix and convert all
chlorine present in the sample to hydrogen chloride. 8.6 SodiumAcetate, anhydrous, (NaCH CO ), fine granular.
3 2
7.2 Pyrolysis Tube, made of quartz and constructed so that 8.7 Cell Electrolyte Solution—Dissolve 1.35 g sodium ac-
when a sample is volatilized in the front of the furnace, it is etate (NaCH CO ) in 850 mL of acetic acid (CH COOH), and
3 2 3
swept into the pyrolysis zone by an inert gas, where it dilute to 1000 mL with water or follow manufacturer’s
combusts when in the presence of oxygen. The inlet end of the recommendations.
tube must have a sample inlet port with a septum through
NOTE 2—Bulk quantities of the electrolyte should be stored in a dark
which the sample can be injected by syringe. The inlet end
bottle or in a dark place and be prepared fresh at least every two weeks.
must also have side arms for the introduction of oxygen and
inert carrier gas. The pyrolysis tube must be of ample volume,
so that complete pyrolysis of the sample is ensured.
Reagent Chemicals, American Chemical Society Specifications, American
Chemical Society, Washington, DC. For suggestions on the testing of reagents not
7.3 Titration Cell, containing a reference and sensor pair of
listed by the American Chemical Society, see Analar Standards for Laboratory
electrodes and a generator anode/cathode pair of electrodes to
Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
maintain constant chloride ion concentration.An inlet from the
and National Formulary, U.S. Pharmaceutical Convention, Inc. (USPC), Rockville,
pyrolysis tube and magnetic stirring is also required. MD.
D5808 − 09a (2014)
8.8 Oxygen, 99.6 % minimum purity is required as the 11.4 Prebake the sample boats to be used for the determi-
reactant gas. nation.
8.9 Gas Regulators, two-stage gas r
...
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