ASTM D5917-15(2019)
(Test Method)Standard Test Method for Trace Impurities in Monocyclic Aromatic Hydrocarbons by Gas Chromatography and External Calibration
Standard Test Method for Trace Impurities in Monocyclic Aromatic Hydrocarbons by Gas Chromatography and External Calibration
SIGNIFICANCE AND USE
5.1 Determining the type and amount of hydrocarbon impurities remaining from the manufacture of toluene, mixed xylenes, and p-xylenes used as chemical intermediates and solvents is often required. This test method is suitable for setting specifications and for use as an internal quality control tool where these products are produced or are used. Typical impurities are: alkanes containing 1 to 10 carbons atoms, benzene, toluene, ethylbenzene (EB), xylenes, and aromatic hydrocarbons containing nine carbon atoms.
5.2 Purity is commonly reported by subtracting the determined expected impurities from 100.00. However, a gas chromatographic analysis cannot determine absolute purity if unknown or undetected components are contained within the material being examined.
5.3 This test method is similar to Test Method D2360, however, interlaboratory testing has indicated a bias may exist between the two methods. Therefore the user is cautioned that the two methods may not give comparable results.
SCOPE
1.1 This test method covers the determination of the total nonaromatic hydrocarbons and trace monocyclic aromatic hydrocarbons in toluene, mixed xylenes, and p-xylene by gas chromatography. The purity of toluene, mixed xylenes, or p-xylene can also be calculated. Calibration of the gas chromatographic system is done by the external standard calibration technique. A similar test method, using the internal standard calibration technique, is Test Method D2360.
1.2 Total aliphatic hydrocarbons containing 1 through 10 carbon atoms (methane through decanes) can be detected by this test method at concentrations ranging from 0.001 to 2.500 weight %.
1.2.1 A small amount of benzene in mixed xylenes or p-xylenes may not be distinguished from the nonaromatics and the concentrations are determined as a composite (see 6.1).
1.3 Monocyclic aromatic hydrocarbon impurities containing 6 through 10 carbon atoms (benzene through C10 aromatics) can be detected by this test method at individual concentrations ranging from 0.001 to 1.000 weight %.
1.4 In determining the conformance of the test results to applicable specifications, results shall be rounded off in accordance with the rounding-off method of Practice E29.
1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.6 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use. For specific hazard statement, see Section 9.
1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
General Information
Relations
Standards Content (Sample)
This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D5917 − 15 (Reapproved 2019)
Standard Test Method for
Trace Impurities in Monocyclic Aromatic Hydrocarbons by
Gas Chromatography and External Calibration
This standard is issued under the fixed designation D5917; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom-
1.1 This test method covers the determination of the total
mendations issued by the World Trade Organization Technical
nonaromatic hydrocarbons and trace monocyclic aromatic
Barriers to Trade (TBT) Committee.
hydrocarbons in toluene, mixed xylenes, and p-xylene by gas
chromatography. The purity of toluene, mixed xylenes, or
2. Referenced Documents
p-xylene can also be calculated. Calibration of the gas chro-
2.1 ASTM Standards:
matographic system is done by the external standard calibra-
D841Specification for Nitration Grade Toluene
tion technique. A similar test method, using the internal
D2360Test Method for Trace Impurities in Monocyclic
standard calibration technique, is Test Method D2360.
Aromatic Hydrocarbons by Gas Chromatography (With-
1.2 Total aliphatic hydrocarbons containing 1 through 10
drawn 2016)
carbon atoms (methane through decanes) can be detected by
D3437Practice for Sampling and Handling Liquid Cyclic
this test method at concentrations ranging from 0.001 to 2.500
Products
weight %.
D4052Test Method for Density, Relative Density, and API
1.2.1 A small amount of benzene in mixed xylenes or
Gravity of Liquids by Digital Density Meter
p-xylenesmaynotbedistinguishedfromthenonaromaticsand
D4307Practice for Preparation of Liquid Blends for Use as
the concentrations are determined as a composite (see 6.1).
Analytical Standards
1.3 Monocyclicaromatichydrocarbonimpuritiescontaining
D4790Terminology ofAromatic Hydrocarbons and Related
6 through 10 carbon atoms (benzene through C aromatics)
10 Chemicals
canbedetectedbythistestmethodatindividualconcentrations
D5136Specification for High Purity p-Xylene
ranging from 0.001 to 1.000 weight %.
D5211Specification for Xylenes for p-Xylene Feedstock
D6526Test Method for Analysis of Toluene by Capillary
1.4 In determining the conformance of the test results to
Column Gas Chromatography (Withdrawn 2018)
applicable specifications, results shall be rounded off in accor-
D6563Test Method for Benzene, Toluene, Xylene (BTX)
dance with the rounding-off method of Practice E29.
Concentrates Analysis by Gas Chromatography (With-
1.5 The values stated in SI units are to be regarded as
drawn 2018)
standard. No other units of measurement are included in this
D6809Guide for Quality Control and Quality Assurance
standard.
Procedures for Aromatic Hydrocarbons and Related Ma-
1.6 This standard does not purport to address all of the
terials
safety concerns, if any, associated with its use. It is the
E29Practice for Using Significant Digits in Test Data to
responsibility of the user of this standard to establish appro-
Determine Conformance with Specifications
priate safety, health, and environmental practices and deter-
E260Practice for Packed Column Gas Chromatography
mine the applicability of regulatory limitations prior to use.
E355PracticeforGasChromatographyTermsand Relation-
For specific hazard statement, see Section 9.
ships
1.7 This international standard was developed in accor-
E691Practice for Conducting an Interlaboratory Study to
dance with internationally recognized principles on standard-
Determine the Precision of a Test Method
This test method is under the jurisdiction of ASTM Committee D16 on
Aromatic, Industrial, Specialty and Related Chemicals and is the direct responsi- For referenced ASTM standards, visit the ASTM website, www.astm.org, or
bility of Subcommittee D16.01 on Benzene, Toluene, Xylenes, Cyclohexane and contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Their Derivatives. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved June 1, 2019. Published June 2019. Originally the ASTM website.
ɛ1 3
approved in 1996. Last previous edition approved in 2015 as D5917–15 . DOI: The last approved version of this historical standard is referenced on
10.1520/D5917-15R19. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D5917 − 15 (2019)
E1510Practice for Installing Fused Silica Open Tubular bons. Therefore the concentrations are determined as a com-
Capillary Columns in Gas Chromatographs posite. In the event that the benzene concentration must be
2.2 Other Document: determined, an alternate method such as Test Method D6526
OSHA Regulations, 29 CFRparagraphs 1910.1000 and must be selected to ensure an accurate assessment of the
1910.1200 benzene concentration.
6.2 Complete separation of ethylbenzene and m-xylene
3. Terminology
from p-xyleneisdifficultandcanbeconsideredadequateifthe
3.1 SeeTerminology D4790 for definitions of terms used in
distance from baseline to valley between peaks is not greater
this test method.
than 50% of the peak height of the impurity.
3.2 Mixed xylenes are a mixture of C aromatics including
7. Apparatus
m-xylene, o-xylene, and p-xylene. Industry convention in-
cludes ethylbenzene as a ‘mixed xylene’though ethylbenzene
7.1 Gas Chromatograph—Any instrument having a flame
is not technically a xylene. Styrene is excluded.
ionization detector that can be operated at the conditions given
inTable1.Thesystemshallhavesufficientsensitivitytoobtain
4. Summary of Test Method
a minimum peak height response for 0.001 weight % impurity
4.1 A repeatable volume of the specimen to be analyzed is
of twice the height of the background noise.
precisely injected into a gas chromatograph equipped with a
7.2 Columns—The choice of column is based on resolution
flameionizationdetector(FID).Thepeakareaofeachimpurity
requirements. Any column may be used that is capable of
is measured. Concentration of each impurity is determined
resolving all significant impurities from the major component.
from the linear calibration curve of peak area versus concen-
The column and conditions described in Table 1 have been
tration. Purity by gas chromatography (GC) is calculated by
used successfully and shall be used as a referee in cases of
subtracting the sum of the impurities found from 100.00.
dispute.
Results are reported in weight percent.
7.3 Recorder—Electronic integration is recommended.
5. Significance and Use
7.4 Injector—The specimen must be precisely and repeat-
5.1 Determining the type and amount of hydrocarbon im-
ablyinjectedintothegaschromatograph.Anautomaticsample
purities remaining from the manufacture of toluene, mixed
injection device is highly recommended although manual
xylenes, and p-xylenes used as chemical intermediates and
injection can be employed if the criteria in 12.7 can be
solvents is often required. This test method is suitable for
satisfied.
setting specifications and for use as an internal quality control
7.5 Volumetric Flask, 100-mL capacity.
tool where these products are produced or are used. Typical
impurities are: alkanes containing 1 to 10 carbons atoms,
7.6 Syringe, 100 µL.
benzene, toluene, ethylbenzene (EB), xylenes, and aromatic
hydrocarbons containing nine carbon atoms.
TABLE 1 Recommended Operating Conditions
5.2 Purity is commonly reported by subtracting the deter-
Inlet Split
mined expected impurities from 100.00. However, a gas Temperature, °C 270
Column:
chromatographic analysis cannot determine absolute purity if
Tubing fused silica
unknown or undetected components are contained within the
Length, m 60
Internal diameter, mm 0.32
material being examined.
Stationary phase crosslinked polyethylene glycol
5.3 This test method is similar to Test Method D2360,
Film thickness, µm 0.25
Column temperature program
however, interlaboratory testing has indicated a bias may exist
Initial temperature, °C 60
between the two methods. Therefore the user is cautioned that
Initial time, min 10
the two methods may not give comparable results.
Programming rate, °C/min 5
Final, °C 150
6. Interferences Time 2, min 10
Carrier gas Helium or Hydrogen
6.1 Insomecasesformixedxylenesand p-xylene,itmaybe
Linear velocity, cm/s at 145°C 20 Helium or 45 Hydrogen
Split ratio 100:1
difficult to resolve benzene from the nonaromatic hydrocar-
Sample size, µL 1.0
Detector: flame ionization
AvailablefromU.S.GovernmentPrintingOfficeSuperintendentofDocuments,
Temperature, °C 300
732 N. Capitol St., NW, Mail Stop: SDE, Washington, DC 20401, http://
Analysis time, min 30
www.access.gpo.gov.
D5917 − 15 (2019)
8. Reagents 9. Hazards
8.1 Purity of Reagent—Reagent grade chemicals shall be 9.1 Consult current OSHA regulations, supplier’s Safety
used in all tests. Unless otherwise indicated, it is intended that Data Sheets, and local regulations for all materials used in this
all reagents shall conform to the specifications of the Commit- test method.
teeonAnalyticalReagentsoftheAmericanChemicalSociety,
10. Sampling
where such specifications are available.
10.1 Sample the material in accordance with Practice
8.2 Carrier Gas—Chromatographic grade helium or
D3437.
hydrogen, 99.999% is recommended. Purify carrier, fuel and
makeup gases by adding traps to reduce the concentration of
11. Preparation of Apparatus
any remaining oxygen, water, and hydrocarbons. Purify air by
adding traps to reduce the concentration of any remaining
11.1 Follow manufacturer’s instructions for mounting and
hydrocarbons and water.
conditioning the column into the chromatograph and adjusting
the instrument to the conditions described in Table 1, allowing
8.3 Air, Chromatographic grade, containing less than 0.1
sufficient time for the equipment to reach equilibrium. See
ppm THC.
PracticesE260,E355,andE1510foradditionalinformationon
8.4 High Purity p-Xylene, 99.999 weight % or greater
gas chromatography practices and terminology.
purity.
8.4.1 Most p-xylene is available commercially at a purity
12. Calibration
less than 99.9% and can be purified by recrystallization. To
12.1 Prepare a synthetic mixture of high purity p-xylene
prepare 1.9 L of high purity p-xylene, begin with approxi-
containing impurities at concentrations representative of those
mately 3.8 L of material and cool in a flammable storage
expected in the samples to be analyzed. The volume of each
1 3
freezer at −10 6 5°C until approximately ⁄2 to ⁄4 of the
hydrocarbon impurity must be measured to the nearest 1 µL
p-xylenehasfrozen.Thisshouldrequireabout5h.Removethe
and all liquid reference compounds must be brought to the
sample and decant the liquid portion. The solid portion is the
same temperature before mixing. Refer to Table 2 for an
purified p-xylene. Allow the p-xylene to thaw and repeat the
example of a calibration blend. n-Nonane will represent the
crystallization procedure on the remaining sample until the
nonaromatic fraction, o-xylene the o-xylene fraction, m-xylene
p-xylene is free of contamination as indicated by gas chroma-
the m-xylene fraction. Cumene will represent the aromatic
tography.
hydrocarbons containing nine carbon atoms or greater, with
8.5 Pure compounds for calibration, shall include n-nonane,
exception of PDEB. If PDEB is included in the calibration,
benzene, toluene, ethylbenzene, o-xylene, m-xylene, and
PDEB will represent PDEB.
cumene. If applicable, the calibration may include paradieth-
12.1.1 Prior to preparing the calibration standard, all refer-
ylbenzene (PDEB). The purity of all reagents should be >99
ence compounds and any samples to be analyzed must be
weight%.Ifthepurityislessthan99%,theconcentrationand
brought to the same temperature, preferably ambient or 20°C.
identification of impurities must be known so that the compo-
12.2 Using the exact volumes and densities in Table 2,
sition of the standard can be adjusted for the presence of the
calculate the weight % concentration for each impurity in the
impurities.
calibration blend as follows:
C 5 100 D V /~V D ! (1)
i i i t p
where:
Reagent Chemicals, American Chemical Society Specifications, American
D = density of impurity i from Table 2,
i
Chemical Society, Washington, DC. For suggestions on the testing of reagents not
V = volume of impurity i, mL,
i
listed by the American Chemical Society, see Analar Standards for Laboratory
D = density of p-xylene from Table 2,
p
Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,
MD.
TABLE 2 Preparation of Calibration Blend
Resulting Concentration (including Resulting Concentration (excluding
Recommended
A
PDEB) PDEB)
Compound Density
Vol, µL
Volume % Weight % Volume % Weight %
p-Xylene 0.861 99.60-99.62 ml 99.60 99.60 99.62 99.62
Benzene 0.879 20 0.020 0.020 0.020 0.020
Toluene 0.867 20 0.020 0.020 0.020 0.020
Ethylbenzene 0.867 100 0.100 0.100 0.100 0.100
o-Xylene 0.880 100 0.100 0.102 0.100 0.102
Cumene 0.862 20 0.020 0.020 0.020 0.020
n-Nonane 0.718 20 0.020 0.017 0.020 0.017
m-Xylene 0.864 100 0.100 0.101 0.100 0.101
PDEB 0.866 20 0.020 0.020 n/a n/a
A
Density at 20°C. Values obtained from “Physical Constants of Hydrocarbons C to C ;” ASTM Publication DS 4A, 1971.
1 10
D5917 − 15 (2019)
where:
V = total volume of standard blend, mL, and
t
C = concentration of impurity i, weight %.
CV = coefficient of variation for RF,
i
i i
SD = standard deviation for RF, and
i i
12.2.1 Alternatively, calibration standards may be used that
Avg = average RF of impurity i.
i
havebeengravimetricallypreparedinaccordancewithPractice
12.7 The coefficient of variation for the response factor of
D4307.
any impurity, as calculated from a minimum of three succes-
12.3 Inject the resulting solution from 12.1 into the
sive analyses of the standard, shall not exceed 10%.
chromatograph, collect and process the data. A typical chro-
matogram is illustrated in Fig. 1.
13. Procedure
12.4 Determine the response factor for each impurity in the
13.1 Bring the sample and calibration mixtures to identical
calibration mixture as follows:
temperatures, preferably ambient or 20°C. Make sure that the
RF 5 C /A (2)
temperature of the sample is consistent with that of
...
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