ASTM D4275 - 17

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Designation: D4275 −17
Standard Test Method for
Determination of Butylated Hydroxy Toluene (BHT) in
Polymers of Ethylene and Ethylene–Vinyl Acetate (EVA)
Copolymers by Gas Chromatography
1
This standard is issued under the fixed designation D4275; 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 describes a procedure for the determi-
nation of butylated hydroxy toluene (BHT) (2,6-di-t-butyl-
4-methyl-hydroxybenzene) in polymers of ethylene and
ethylene-vinyl acetate (EVA) copolymers by solvent extraction
followed by gas chromatographic analysis. Detection of the
compound is achieved by flame ionization, and quantitative
analysis is obtained by use of internal or external standards, as
described in Practices E260,E355, and E594.
1.2 The values stated in SI units are to be regarded as the
standard. The values given in parentheses are for information
only.
1.3 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 appro-
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use. Specific precau-
tionary statements are given in Section 9.
NOTE 1—There is no known ISO equivalent for this test method.
2. Referenced Documents
2.1 ASTM Standards:
2
D883 Terminology Relating to Plastics
D4968 Practice for Annual Review of Test Methods and
Specifications for Plastics
D7210 Practice for Extraction of Additives in Polyolefin
Plastics
E260 Practice for Packed Column Gas Chromatography
E355 Practice for Gas Chromatography Terms and Relation-
ships
E594 Practice for Testing Flame Ionization Detectors Used
in Gas or Supercritical Fluid Chromatography
E691 Practice for Conducting an Interlaboratory Study to
Determine the Precision of a Test Method
IEEE/ASTM SI-10 Practice for Use of the International
System of Units (SI) (the Modernized Metric System)
3. Terminology
3.1 Definitions—Units and symbols used in this test method
are those recommended in Practice IEEE/ASTM SI-10. Chro-
matographic terms and relationships are as described in Prac-
tice E355.
3.2 Abbreviations:
3.2.1 BHT—Butylated hydroxy toluene (2,6-di-tert-butyl-4-
methyl-hydroxybenzene).
3.2.2 MM—Methyl myristate.
3.2.3 EVA—Ethylene-vinyl acetate copolymers.
3.2.4 LDPE—Low-density polyethylene.
3.2.5 HDPE—High-density polyethylene.
4. Summary of Test Method
4.1 The BHT from a finely ground polymer sample is
extracted by shaking or refluxing with cyclohexane or isopro-
panol. A known volume of this extract is injected into a gas
chromatographic column packed with a liquid-coated solid
support. Passing through this column in a stream of carrier gas,
BHT is separated from the extraction solvent and other
components. Responses of BHT and any internal standard are
measured by a flame ionization detector. This signal is re-
corded to indicate the relative concentration and retention time
of BHT.
5. Significance and Use
5.1 Separation and identification of stabilizers used in the
manufacture of polyethylene are necessary in order to correlate
performance properties with polymer composition.
5.2 The BHT extraction procedure is made effective by the
insolubility of the polymer sample in solvents generally used
for gas chromatographic analysis.
1
This test method is under the jurisdiction of ASTM Committee D20 on Plastics
and is the direct responsibility of Subcommittee D20.70 on Analytical Methods.
Current edition approved March 1, 2017. Published March 2017. Originally
approved in 1983. Last previous edition approved in 2009 as D4275 - 09. DOI:
10.1520/D4275-17.
2
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
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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.
1
6. Interferences
6.1 Any material eluting at or near the BHT or MM
retention times will cause erroneous results. Prior to extraction,
solvent blanks shall be analyzed to confirm the absence of
interfering peaks.
7. Apparatus
7.1 Reflux Extraction, consisting of 250-mL round-bottom
flask with condenser and heating mantle to fit.
7.2 Wiley Mill, with 10 and 20-mesh screens.
7.3 Wrist-Action Shaker.
7.4 Gas Chromatograph, equipped with a flame ionization
detector.
7.5 Chromatographic Column, 3.2-mm outside diameter
times 1.8 m packed with 20 % UCW-98 on 80/100 mesh
Chromosorb P, a similar packed column, or an equivalent
capillary column, such as a HP-1 or DB-1.
7.6 Integrator, capable of measuring the net peak area on the
back side of a solvent peak.
7.7 Gas Chromatographic Syringe, 10 µL.
7.8 Analytical Balance, capable of weighing to 60.0001 g.
7.9 Pressure Regulators, for all required gas cylinders.
7.10 Filter-Dried Assemblies, for each required gas cylin-
der.
7.11 Soap Film Flowmeter and Stopwatch, or other means
of measuring gas flow rates.
8. Reagents and Materials
8.1 Cyclohexane, reagent grade.
8.2 Isopropyl Alcohol, reagent grade.
8.3 Methyl Myristate,
3
99
+
%, boiling point 323°C (internal
standard).
8.4 Butylated Hydroxy Toluene, food grade (2,6-di-tert-
butyl-4-methyl-hydroxybenzene).
8.5 Hydrogen Cylinder, prepurified.
8.6 Nitrogen Cylinder, prepurified, oxygen-free for carrier
gas.
NOTE 2—Helium or hydrogen may also be used as the carrier gas.
8.7 Air, breathing or water-pumped.
9. Safety Precautions
9.1 Cyclohexane and isopropyl alcohol are flammable. This
extraction procedure shall be carried out in a fume hood.
10. Preparation of Gas Chromatograph
10.1 Install the chromatographic column and condition
overnight at 200°C with carrier gas flow rate of 35 mL/min. Do
not connect the exit end of the column to the detector during
this conditioning period. Turn off hydrogen and air flows to the
detector while the column is disconnected.
10.2 Connect the exit end of the column to the detector. Set
optimum hydrogen and air flow rates for the detector as
specified for the chromatograph model in use, or as determined
experimentally.
10.3 Set chromatograph temperatures as follows:
10.3.1 Oven (chromatographic column), 160°C.
10.3.2 Injection block, 220°C.
10.3.3 Detector block, 240°C.
11. Calibration by Internal Standard
11.1 Weigh a syringe containing approximately 80 mg of
methyl myristate.
11.2 Transfer syringe contents to a 2-L volumetric flask and
immediately reweigh the syringe (60.1 mg).
11.3 Dilute to volume with extraction solvent (cyclohexane
or isopropyl alcohol) and store in a tightly stoppered flask.
11.4 Weigh and transfer 20 60.1 mg of BHT into a 500-mL
volumetric flask.
11.5 Dissolve BHT in the internal standard solution in
accordance with 11.3 and dilute to volume using this same
solution.
11.6 Inject 2 µL of this calibration mixture into the gas
chromatograph equilibrated to the conditions of 10.3.
11.7 Chromatograph BHT and MM and record their respec-
tive peak areas using an integrator.
NOTE 3—The BHT and methyl myristate peak elute at approximately
3.5 and 8 min, respectively.
11.8 Using BHT and MM areas from 11.7, determine the
relative response factor (R
f
) as follows:
R
f
5concentration
~
mg/L
!
BHT 3area MM
concentration
~
mg/L
!
MM 3area BHT (1)
11.9 Average response factors for five replicate injections of
the calibration mixture.
12. Calibration by External Standard
12.1 Weigh 100 61 mg of BHT into a 200-mL volumetric
flask.
12.2 Dissolve in the selected extraction solvent (cyclo-
hexane or isopropyl alcohol) and dilute to volume.
12.3 Pipet 2.0, 4.0, 6.0, and 8.0 mL of the above stock
solution into a series of 100-mL volumetric flasks and dilute to
volume with the appropriate solvent.
12.4 Inject 2 µL of each dilute standard into the gas
chromatograph equilibrated to the conditions of 10.3.
12.5 Measure the BHT peak area for each standard.
12.6 Repeat the injection of each standard and average the
peak area results for duplicate injections.
12.7 Plot the peak area on the y-axis versus concentration
(µg/mL) for each standard on the x-axis. The slope of this curve
is proportional to the flame response for BHT.
3
The sole source of supply of the methyl myristate known to the committee at
this time is Aldrich Chemical Co., P.O. Box 355, Milwaukee, WI 53201. If you are
aware of alternative suppliers, please provide this information to ASTM Interna-
tional Headquarters. Your comments will receive careful consideration at a meeting
of the responsible technical committee,
1
which you may attend.
D4275 − 17
2
NOTE 4—Chromatographic response for BHT should be determined by
each analyst every day. Observe that the curve intercept should be zero.
13. Sample Preparation
13.1 Grind HDPE, LDPE, and EVA samples containing less
than 10 % vinyl acetate to 20-mesh size.
13.2 Grind samples containing greater than 20 % vinyl
acetate to 10-mesh size.
14. Procedure
14.1 Isopropyl Alcohol Extraction:
14.1.1 For analysis of LDPE or EVA, weigh 3 60.001 g of
ground sample into a 250-mL round-bottom flask.
14.1.2 Pipet 25.0 mL of isopropyl alcohol internal standard
solution prepared in 11.3 into the flask and connect it to the
condenser.
NOTE 5—With external standard calibration, substitute the appropriate
solvent for internal standard solution in 11.3 in the above procedure.
14.1.3 Reflux 2 h and cool to room temperature before
removing the flask from the condenser.
14.2 Cyclohexane Extraction:
14.2.1 For HDPE, repeat 14.1.1 – 14.1.3, substituting cy-
clohexane for isopropyl alcohol.
NOTE 6—IPA can be used for HDPE extractions, but the recovery was
found to be 10 % lower than with cyclohexane.
14.2.2 For LDPE or EVA, weigh 3 60.001 g of ground
sample into a 250-mL round-bottom flask. Pipet 25.0 mL of
cyclohexane internal standard solution prepared in 11.3 into the
flask and insert the stopper. Shake at room temperature for 2 h
on a wrist-action shaker.
14.3 Extract Analysis—Inject 2 µL of sample extract into the
gas chromatograph equilibrated to conditions of 10.3. Measure
areas of BHT and methyl myristate peaks (if using internal
standard calibration) and record as ABHT and AMM, respec-
tively.
NOTE 7—Alternative extraction methods may be used in accordance
with Practice D7210.
15. Calculation
15.1 Internal Standard—Using the response factor (R
f
) de-
termined in 11.8 and area responses from chromatography of
sample extracts, calculate the BHT content of each sample
from the following equation:
ppm BHT 5
~
A
BHT
!~
R
f
!~
C
!~
V
!
~
A
MM
!~
W
!
(2)
where:
A
BHT
= area of BHT peak in sample chromatogram,
A
MM
= area of methyl myristate peak in sample
chromatogram,
R
f
= response factor from 11.8,
C= concentration of MM in the internal solution, mg/L,
V= volume of internal standard solution used for
extraction, mL, and
W= weight of sample extracted, g.
15.2 External Standard—Using the calibration slope from
12.7, calculate the BHT content of each sample from the
following equation:
BHT
~
in ppm by weight
!
5BV
SW (3)
where:
B= BHT area from sample chromatogram,
V= volume of extraction solution, mL,
W= weight of sample extracted, g, and
S= slope of calibration curve (from 12.7).
16. Report
16.1 Report the following information:
16.1.1 Sample identification,
16.1.2 Sample preparation method used,
16.1.3 Gas chromatography analysis method used, includ-
ing type of calibration, and
16.1.4 Concentration of BHT in the polymer, ppm.
17. Precision and Bias
17.1 Precision—Table 1 is based on a round robin con-
ducted in accordance with Practice E691 involving two mate-
rials tested by five laboratories. For each material, all samples
were prepared at one source, but specimens were prepared at
the laboratories that tested them. Each test result was an
average of two individual determinations. Each laboratory
obtained two test results for each sample.
17.2 Samples included HDPE and EVA (0 to 19 % VA) with
BHT levels of 70 to 930 µg/g.
17.3 For HDPE containing 150 to 350-µg/g ppm BHT,
values determined using cyclohexane extraction averaged
10 % higher than those derived from isopropanol extraction.
17.4 Bias—There are no recognized standards by which to
estimate the bias of this test method.
NOTE 8—Caution should be exercised with the between-laboratory
results since fewer than six laboratories participated in the round-robin
study.
18. Keywords
18.1 butylated hydroxy toluene; BHT; ethylene-vinyl ac-
etate; gas chromatography; polyethylene
TABLE 1 Summary of Method Precision
Extraction Solvent Expressed as Percent of the Average
CV %
rA
CV %
rB
CV %
RC
Isopropanol
Cyclohexane
2.7
2.9
5.0
4.9
7.4
7.4
A
CV %
r
= within laboratory coefficient of variation between a pair of replicates
(expressed in percent).
B
CV %
r
= within laboratory coefficient of variation of the average of two analyses
on different days (expressed in percent).
C
CV %
R
= between laboratory coefficient of variation of the average (expressed in
percent).
D4275 − 17
3
摘要：

ASTM D4275-17 是国际材料与试验协会发布的标准测试方法，主要用于测定聚氯乙烯（PVC）中聚合抑制剂（如对苯二酚等）的含量。该标准通过萃取和分光光度法或气相色谱法对热稳定剂等添加剂进行量化分析，适用于质量控制、产品合规与研发验证。遵循 ASTM D4275-17 可帮助化工企业、检测机构及认证单位准确评估 PVC 材料中抑制剂的实际残留，确保其在加工及使用过程中的热稳定性与安全性，同时满足各国监管要求。

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