ASTM D6144-22

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Designation: D6144 − 17 D6144 − 22
Standard Test Method for
Analysis of AMS (α-Methylstyrene) by Capillary Gas
Chromatography
This standard is issued under the fixed designation D6144; 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*
1.1 This test method covers the determination of the purity of AMS (α-methylstyrene) 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 cumene, 3-methyl-2-cyclopentene-1-one,
n-propylbenzene, tert-butylbenzene, sec-butylbenzene, cis-2-phenyl-2-butene, acetophenone, 1-phenyl-1-butene, 2-phenyl-2-
propanol, trans-2-phenyl-2-butene, m-cymene, p-cymene, and phenol, which are common to the manufacturing process of AMS.
The method has also been found applicable for the determination of para-tertiary-butylcatechol (TBC or PTBC) typically added
as a stabilizer to AMS. The impurities in AMS can be analyzed over a range of 5 to 800 mg/kg by this method. (See Table 1.) The
Table 2.) Based on the results in ASTM Research Report RR:D16-1022, summarized in Table 2, the limit of quantitation for these
these impurities averages 4 mg/kg, while the limit of detection averages 1.21.2 mg mg/kg. (See ⁄kg. Table 1.)
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 E29.
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.5 This standard does not purport to address all the safety concerns, if any, associated with its use. It is the responsibility of
the user of this standard to establish appropriate safety safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use. For specific hazard statements, see Section 8.
1.6 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.
2. Referenced Documents
2.1 ASTM Standards:
D3437 Practice for Sampling and Handling Liquid Cyclic Products
D4307 Practice for Preparation of Liquid Blends for Use as Analytical Standards
D4790 Terminology of Aromatic Hydrocarbons and Related Chemicals
D6809 Guide for Quality Control and Quality Assurance Procedures for Aromatic Hydrocarbons and Related Materials
This test method is under the jurisdiction of ASTM Committee D16 on Aromatic, Industrial, Specialty and Related Chemicals and is the direct responsibility of
Subcommittee D16.07 on Styrene, Ethylbenzene and C9 and C10 Aromatic Hydrocarbons.
Current edition approved June 1, 2017Jan. 1, 2022. Published June 2017January 2022. Originally approved in 1997. Last previous edition approved in 20132017 as
D6144D6144 – 17. – 13. DOI: 10.1520/D6144-17.10.1520/D6144-22.
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 the ASTM website.
*A Summary of Changes section appears at the end of this standard
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D6144 − 22
TABLE 12 Summary of Precision Data (mg/kg)
Compound Repeatability (r) Reproducibility (R) Range Studied
Acetone 1.61 + 0.035*Acetone 0.47 + 1.10*Acetone 0.5 – 26
Cumene −0.46 + 0.031*Cumene 7.88 + 0.19*Cumene 45 – 290
Cumene –0.46 + 0.031*Cumene 7.88 + 0.19*Cumene 45 – 290
nPropylbenzene (NPB) 2.11 + 0.03*NPB −7.81 + 0.37*NPB 55 – 195
n-Propylbenzene (NPB) 2.11 + 0.03*NPB –7.81 + 0.37*NPB 55 – 195
Phenol 1.84 3.65 + 0.58*Phenol 1 – 40
tertButylbenzene (TBB) −1.22 + 0.035*TBB 3.63 + 0.087*TBB 150 – 650
tert-Butylbenzene (TBB) –1.22 + 0.035*TBB 3.63 + 0.087*TBB 150 – 650
secButylbenzene (SBB) 4.23 + 0.019*SBB 21.60 + 0.25*SBB 200 – 765
sec-Butylbenzene (SBB) 4.23 + 0.019*SBB 21.60 + 0.25*SBB 200 – 765
mCymene 0.31 + 0.035*mCymene 2.34 + 0.35*mCymene 2 – 50
m-Cymene 0.31 + 0.035*mCymene 2.34 + 0.35*mCymene 2 – 50
oCymene 1.63 8.00 29 – 31
o-Cymene 1.63 8.00 29 – 31
pCymene 5.12 15.79 10 – 18
p-Cymene 5.12 15.79 10 – 18
cis-2-Phenyl-2-Butene (CPB) 0.17 + 0.030*CPB 5.39 + 0.11*CPB 50 – 225
trans-2-Phenyl-2-Butene (TPB) 1.57 0.54 + 0.20*TPB 19 – 70
trans-2-Phenyl-2-Butene (TPB) 1.57 0.54 + 0.20*TPB 19 – 70
1-Phenyl-1-Butene (PB) 4.00 + 0.018*PB 0.17 + 0.19*PB 0.2 – 735
Acetophenone (AP) –1.09 + 0.15*AP 1.17 + 0.63*AP 15 – 115
para-tert-Butylcatechol (PTBC) 2.21 17.82 10 – 19
2-Methylbenzofuran (MBF) 0.33 + 0.76*MBF 0.75 + 0.60*MBF 1 – 2
2-Phenylpropion aldehyde (PPA) 0.59 + 0.11*PPA 0.29 + 0.23*PPA 1.5 – 15
α-Methylstyrene Oxide (AMSO) 4.61 6.51 + 0.23*AMSO 13 – 32
DimethylBenzyl Alcohol (DMBA) 0.38 0.55 + 2.03*DMBA 0.1 – 1
E29 Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications
E355 Practice for Gas Chromatography Terms and Relationships
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
E1510 Practice for Installing Fused Silica Open Tubular Capillary Columns in Gas Chromatographs
2.2 Other Document:
OSHA Regulations, 29 CFR paragraphs 1910.1000 and 1910.1200
3. Terminology
3.1 See Terminology D4790 for definition of terms used in this test method.
4. Summary of Test Method
4.1 AMS (α-methylstyrene) is analyzed by a gas chromatograph (GC) equipped with a flame ionization detector (FID). A precisely
repeatable volume of the sample to be analyzed is injected onto the gas chromatograph. The peak areas of the impurities are
measured and converted to concentrations via an external standard methodology. Purity by GC (the AMS content) is calculated
by subtracting the sum of the impurities from 100.00. Results Purity results are reported in weightmass percent.
5. Significance and Use
5.1 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 AMS is produced or is used in a manufacturing process. It may also be used in development or research work involving
AMS.
5.2 This test method is useful in determining the purity of AMS with normal impurities present. If extremely high boiling or
unusual impurities are present in the AMS, this test method would not necessarily detect them and the purity calculation would
be erroneous.
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D6144 − 22
6. Apparatus
6.1 Gas Chromatograph—Any instrument having a flame ionization detector that can be operated at the conditions given in Table
21. The system should have sufficient sensitivity to obtain a minimum peak height response for 1010 mg mg/kg ⁄kg acetophenone
of twice the height of the signal background noise.
6.2 Columns—The choice of column is based on resolution requirements. Any column may be used that is capable of resolving
all significant impurities from AMS. The column described in Table 21 has been used successfully and shall be used as a referee
in cases of dispute.
6.3 Recorder—Chromatographic data systems are preferred but electronic integration may be used if the user can demonstrate that
the results are consistent with the precision statement. Recorders are not considered adequate for meeting the precision
requirements of this standard.
6.4 Injector—The specimen must be precisely and repeatably injected into the gas chromatograph. An automatic sample injection
device is highly recommended. Manual injection can be employed if the precision stated in Table 1Table 2 can be reliably and
consistently satisfied.
7. Reagents and Materials
7.1 Purity of Reagents—Reagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that all
reagents shall conform to the specification of the Committee on Analytical Reagents of the American Chemical Society, where such
specifications are available. Other grades may be used, provided it is first ascertained that the reagent is of sufficiently high purity
to permit its use without lessening the accuracy of the determination.
TABLE 21 Recommended Operating Conditions
Detector flame ionization
Injection Port capillary splitter
Column A:
Tubing fused silica
Stationary phase crosslinked methylsilicone
Film thickness, ÷μm 1.0
Length, m 60
Diameter, mm 0.32
Temperatures:
Injector, °C 250
Detector, °C 300
Oven, °C 85 hold for 13 min
Ramp 1 = 6°C/min to 125°C,
hold for 2 min
Ramp 2 = 30°C/min to 250°C,
hold for 7.5 min
Oven, °C 85 hold for 13 min
Ramp 1 = 6 °C ⁄min to 125 °C,
hold for 2 min
Ramp 2 = 30 °C ⁄min to 250 °C,
hold for 7.5 min
Carrier gas helium
Flow rate, mls/min 3
Flow rate, mL/min 3
Split ratio 60:1
Sample size, ÷μl 1.0
Sample size, ÷μL 1.0
Reagent Chemicals, American Chemical Society Specifications,ACS Reagent Chemicals, Specifications and Procedures for Reagents and Standard-Grade Reference
Materials, American Chemical Society, Washington, DC. For Suggestionssuggestions on the testing of reagents not listed by the American Chemical Society, see Analar
Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia and National Formulary, U.S. Pharmacopeial Convention, Inc.
(USPC), Rockville, MD.
D6144 − 22
7.2 Carrier Gas, Makeup, and Detector Gases—Helium, hydrogen, nitrogen, or other carrier, makeup and detector gases 99.999 %
minimum purity. Oxygen in carrier gas less than 1 ppm, 1 ppm, less than 0.5 ppm 0.5 ppm is preferred. Purify carrier, makeup,
and detector gases to remove oxygen, water, and hydrocarbons. Warning—Helium carrier, makeup, and detector gas was used to
develop this standard. Use of other gases requires different conditions. The user must conduct the necessary evaluation to determine
that equivalent results are obtained.
7.3 Compressed Air—Purify air to remove water and hydrocarbons. Air for a FID should contain less than 0.1 ppm THC.0.1 ppm
THC (total hydrocarbon content).
7.4 Equipment Setup Check Sample:
7.4.1 For GC standards, a setup check sample should be included to:
7.4.1
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