ASTM D7057-04
(Test Method)Standard Test Method for Analysis of Isopropylbenzene (Cumene) by Gas Chromatography (External Standard)
Standard Test Method for Analysis of Isopropylbenzene (Cumene) by Gas Chromatography (External Standard)
SIGNIFICANCE AND USE
This test method is suitable for setting specifications on the materials referenced in 1.2 and for use as an internal quality control tool where isopropylbenzene is produced or is used in a manufacturing process. It may also be used in development or research work involving isopropylbenzene.
This test method is useful in determining the purity of isopropylbenzene with normal impurities present. If extremely high boiling or unusual impurities are present in the isopropylbenzene, this test method would not necessarily detect them and the purity calculation would be erroneous.
Cumene hydroperoxide, if present, will yield thermal decomposition products, primarily AP and DMPC as stated in 4.1, that will elute in the chromatogram thereby giving incorrect results unless they are excluded as indicated in 4.1. It is also possible to get erroneous results for trace alpha-methylstyrene present in isopropylbenzene if the inlet has become unduly contaminated with non-volatile foreign substances.
The nonaromatic hydrocarbons commonly present from the isopropylbenzene manufacturing process, particularly a non-zeolitic one, will interfere with the determination of xylenes (if present).
SCOPE
1.1 This test method covers the determination of the purity of isopropylbenzene (cumene) by gas chromatography. Calibration of the gas chromatography system is done by the external standard calibration technique.
1.2 This test method has been found applicable to the measurement of impurities such as nonaromatic hydrocarbons, benzene, toluene, ethylbenzene, phenol, cymenes, t-butylbenzene, n-butylbenzene, n-propylbenzene, alpha-methylstyrene, sec-butylbenzene, and diisopropylbenzenes, which are impurities that can be found in isopropylbenzene. The latter impurities can be analyzed over a range of 1 mg/kg to 500 mg/kg by this method (see Table 1). The limit of detection for these impurities is summarized in Table 1 as well.
1.3 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 E 29.
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. For specific hazard statements, see Section 8.
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Designation:D7057–04
Standard Test Method for
Analysis of Isopropylbenzene (Cumene) by Gas
Chromatography (External Standard)
This standard is issued under the fixed designation D 7057; 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 D 6809 Guide for Quality Control and Quality Assurance
Procedures for Aromatic Hydrocarbons and Related Ma-
1.1 This test method covers the determination of the purity
terials
of isopropylbenzene (cumene) by gas chromatography. Cali-
E 29 Practice for Using Significant Digits in Test Data to
bration of the gas chromatography system is done by the
Determine Conformance with Specifications
external standard calibration technique.
E 355 Practice for Gas Chromatography Terms and Rela-
1.2 This test method has been found applicable to the
tionships
measurement of impurities such as nonaromatic hydrocarbons,
E 691 Practice for Conducting an Interlaboratory Study to
benzene, toluene, ethylbenzene, phenol, cymenes,
Determine the Precision of a Test Method
t-butylbenzene, n-butylbenzene, n-propylbenzene, alpha-
E 1510 Practice for Installing Fused Silica Open Tubular
methylstyrene, sec-butylbenzene, and diisopropylbenzenes,
Columns in Gas Chromatographs
which are impurities that can be found in isopropylbenzene.
2.2 Other Document:
The latter impurities can be analyzed over a range of 1 mg/kg
OSHA Regulations, 29CFR paragraphs 1910.1000 and
to 500 mg/kg by this method (see Table 1). The limit of
1910.1200
detection for these impurities is summarized inTable 1 as well.
1.3 In determining the conformance of the test results using
3. Terminology
this method to applicable specifications, results shall be
3.1 See Terminology D 4790 for definition of terms used in
rounded off in accordance with the rounding-off method of
this test method.
Practice E 29.
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 Cumene (isopropylbenzene) is analyzed by a gas chro-
responsibility of the user of this standard to establish appro-
matograph (GC) equipped with a flame ionization detector
priate safety and health practices and determine the applica-
(FID). A precisely repeatable volume of the sample to be
bility of regulatory limitations prior to use. For specific hazard
analyzed is injected onto the gas chromatograph. The peak
statements, see Section 8.
areas of the impurities are measured and converted to concen-
2. Referenced Documents trations via an external standard methodology. Purity by GC
2 (the Cumene content) is calculated by subtracting the sum of
2.1 ASTM Standards:
the impurities from 100.00, excludingAcetophenone (AP) and
D 3437 Practice for Sampling and Handling Liquid Cyclic
2-phenyl-2-propanol (DMPC or DMBA) which are artifacts of
Products
cumene hydroperoxide (CHP) thermal decomposition in the
D 4307 PracticeforPreparationofLiquidBlendsforUseas
inlet of the GC. Results are reported in weight percent.
Analytical Standards
D 4790 Terminology of Aromatic Hydrocarbons and Re-
5. Significance and Use
lated Chemicals
5.1 This test method is suitable for setting specifications on
thematerialsreferencedin1.2andforuseasaninternalquality
This test method is under the jurisdiction of ASTM Committee D16 on
control tool where isopropylbenzene is produced or is used in
Aromatic Hydrocarbons and Related Chemicals and is the direct responsibility of
a manufacturing process. It may also be used in development
Subcommittee D16.07 on Styrene, Ethylbenzene, and C and C Aromatic
9 10
or research work involving isopropylbenzene.
Hydrocarbons.
Current edition approved June 1, 2004. Published July 2004.
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
Standards volume information, refer to the standard’s Document Summary page on Available from Superintendent of Documents, U.S. Government Printing
the ASTM website. Office, Washington, DC 20402.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D7057–04
TABLE 1 Summary of Precision Data (mg/kg)
Range
Compound Repeatability Reproducibility
Studied
Benzene 1.004+0.006*Benzene 0.924+0.158*Benzene 1.0–295
Toluene 0.644+0.009*Toluene 1.505+0.069*Toluene 0.2–260
Ethylbenzene (EB) 1.249+0.022*EB 2.534+0.230*EB 5–370
n-Propylbenzene (NPB) -0.369+0.015*NPB -6.793+0.214*NPB 180–465
Phenol (PHE) 1.926+.0095*PHE 3.718+0.207*PHE 1–225
alpha-methylstyrene(AMS) 1.368+0.057*AMS 21.181+0.976*AMS 6–305
tert-Butylbenzene(TBB) 1.666+0.011*TBB 4.126+0.086*TBB 2–250
sec-Butylbenzene(SBB) 0.635+0.010*SBB 0.891+0.090*SBB 2–245
m-Cymene 0.618+0.011*m-Cymene 1.811+0.181*m-Cymene 5–240
o-Cymene 0.498+0.012*o-Cymene 1.951+0.156*o-Cymene 1–160
p-Cymene 0.485+0.019*p-Cymene 1.618+0.097*p-Cymene 2–270
n-Butylbenzene(NBB) 0.445+0.030*NBB 2.600+0.045*NBB 0.3–265
1,3-diisopropylbenzene(13DIPB) 0.727+0.010*13DIPB 1.570+0.720*13DIPB 1–210
1,4-diisopropylbenzene(14DIPB) 0.435+0.013*14DIPB 1.112+0.040*14DIPB 1–285
NonAromatics(NA) 0.441+0.242*NA 1.663+0.306*NA 5–95
5.2 This test method is useful in determining the purity of 6.2 Columns—The choice of column is based on resolution
isopropylbenzene with normal impurities present. If extremely requirements. Any column may be used that is capable of
high boiling or unusual impurities are present in the isopropy- resolving all significant impurities from isopropylbenzene.The
lbenzene, this test method would not necessarily detect them columndescribedinTable2hasbeenusedsuccessfully.Unless
and the purity calculation would be erroneous. the analyst can be sure of peak identity, for example by gas
5.3 Cumene hydroperoxide, if present, will yield thermal chromatography-mass spectrometry (GC-MS), the use of the
decomposition products, primarily AP and DMPC as stated in column in Table 2 is strongly recommended.
4.1, that will elute in the chromatogram thereby giving 6.3 Recorder—Electronic integration is required.
incorrect results unless they are excluded as indicated in 4.1. It 6.4 Injector—The specimen must be precisely and repeat-
is also possible to get erroneous results for trace alpha- edly injected into the gas chromatograph.An automatic sample
methylstyrene present in isopropylbenzene if the inlet has injection device is highly recommended. Manual injection can
become unduly contaminated with non-volatile foreign sub- be employed if the precision stated in Table 1, Summary of
stances. Precision Data, can be reliably and consistently satisfied.
5.4 The nonaromatic hydrocarbons commonly present from
7. Reagents and Materials
the isopropylbenzene manufacturing process, particularly a
non-zeolitic one, will interfere with the determination of 7.1 Purity of Reagents—Reagent grade chemicals shall be
xylenes (if present). used in all tests. Unless otherwise indicated, it is intended that
all reagents shall conform to the specifications of the Commit-
6. Apparatus tee onAnalytical Reagents of theAmerican Chemical Society,
where such specifications are available. Other grades may be
6.1 Gas Chromatograph—Any instrument having a flame
used, provided it is first ascertained that the reagent is of
ionization detecto
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