ASTM D4322-96(2001)e1
(Test Method)Standard Test Method for Residual Acrylonitrile Monomer Styrene-Acrylonitrile Copolymers and Nitrile Rubber by Headspace Gas Chromatography (Withdrawn 2010)
Standard Test Method for Residual Acrylonitrile Monomer Styrene-Acrylonitrile Copolymers and Nitrile Rubber by Headspace Gas Chromatography (Withdrawn 2010)
SIGNIFICANCE AND USE
For various reasons one may wish to measure the amount of unreacted or residual acrylonitrile monomer in styrene-acrylonitrile copolymers, nitrile rubbers, or ABS terpolymers.
Under optimum conditions, the lowest level of detection of AN in SAN or ABS copolymers and NBR rubbers is approximately 0.5 ppm for the packed column test method and 3 ppm for the capillary test method.
SCOPE
1.1 This test method is suitable for determining the residual acrylonitrile (RAN) content of styrene-acrylonitrile (SAN) copolymer, rubber-modified acrylonitrile-butadiene-styrene (ABS) resins, and nitrile rubber (NBR).
1.2 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. Specific precautionary statements are given in Section 9.
Note 1--Although the packed column option of this test method and ISO 4581:1994 (E) differ in some details, data obtained using either test method should be technically equivalent. There is no equivalent ISO standard for the capillary column option of this test method.
WITHDRAWN RATIONALE
This test method was suitable for determining the residual acrylonitrile (RAN) content of styrene-acrylonitrile (SAN) copolymer, rubber-modified acrylonitrile-butadiene-styrene (ABS) resins, and nitrile rubber (NBR).
Formerly under the jurisdiction of Committee D20 on Plastics, this test method was withdrawn in February 2010 in accordance with subsection 10.5.3.1 of the Regulations Governing ASTM Technical Committees, which requires that standards shall be updated by the end of the eighth year since the last approval date.
General Information
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information.
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Designation: D4322 – 96 (Reapproved 2001)
Standard Test Method for
Residual Acrylonitrile Monomer Styrene-Acrylonitrile
Copolymers and Nitrile Rubber by Headspace Gas
Chromatography
This standard is issued under the fixed designation D4322; 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.
´ NOTE—Several sections were changed editorially in March 2001.
1. Scope 3.2 Abbreviations:Abbreviations:
3.2.1 AN—acrylonitrile.
1.1 This test method is suitable for determining the residual
3.2.2 RAN—residual acrylonitrile.
acrylonitrile (RAN) content of styrene-acrylonitrile (SAN)
3.2.3 SAN—styrene-acrylonitrile copolymer.
copolymer, rubber-modified acrylonitrile-butadiene-styrene
3.2.4 ABS—acrylonitrile-butadiene-styrene copolymer.
(ABS) resins, and nitrile rubber (NBR).
3.2.5 NBR—butadiene-acrylonitrile rubber.
1.2 This standard does not purport to address all of the
3.2.6 DMAC—N,N-dimethylacetamide.
safety concerns, if any, associated with its use. It is the
3.2.7 PN—propionitrile (internal standard).
responsibility of the user of this standard to establish appro-
3.2.8 PC—propylene carbonate.
priate safety and health practices and determine the applica-
3.2.9 ppm—µg RAN/g polymer (parts per million).
bility of regulatory limitations prior to use. Specific precau-
tionary statements are given in Section 9.
4. Summary of Test Method
NOTE 1—Although the packed column option of this test method and
4.1 A dispersion of the polymer in a suitable solvent is
ISO 4581:1994 (E) differ in some details, data obtained using either test
prepared in a headspace vial and sealed. The vial is thermally
method should be technically equivalent. There is no equivalent ISO
equilibrated in a constant temperature bath.
standard for the capillary column option of this test method.
4.2 After equilibrium, a given portion of the sample head-
2. Referenced Documents space is injected into a gas chromatographic column packed
2 with porous polymer beads or a capillary column coated with
2.1 ASTM Standards:
an appropriate liquid phase. Sample injection is achieved using
D4526 Practice for Determination of Volatiles in Polymers
availablecommercialautomaticequipmentoramanualsyringe
by Static Headspace Gas Chromatography
injection technique. Passing through the column in a stream of
E691 Practice for Conducting an Interlaboratory Study to
carrier gas, acrylonitrile is separated from other components
Determine the Precision of a Test Method
that may be present. The response of acrylonitrile is measured
IEEE/ASTM SI-10 Standard for Use of the International
by a nitrogen-specific detector for packed column analysis or a
System of Units (SI): The Modern Metric System
flame ionization detector for capillary column analysis and this
3. Terminology signal is recorded to indicate the retention time and relative
concentration of acrylonitrile.
3.1 Units and Symbols used in this test method are those
recommended in IEEE/ASTM SI-10.
5. Significance and Use
5.1 For various reasons one may wish to measure the
This test method is under the jurisdiction ofASTM Committee D20 on Plastics
amount of unreacted or residual acrylonitrile monomer in
and is the direct responsibility of Subcommittee D20.70 on Analytical Methods.
styrene-acrylonitrile copolymers, nitrile rubbers, or ABS ter-
Current edition approved Dec. 10, 1996. Published May 1997. Originally
polymers.
published as D4322 – 83. Last previous edition D4322 – 83 (1991)´ .
This revision includes the addition of an ISO equivalency statement and a
5.2 Underoptimumconditions,thelowestlevelofdetection
suitable capillary column headspace GC test method. DOI: 10.1520/D4322-
of AN in SAN or ABS copolymers and NBR rubbers is
96R01E01.
2 approximately 0.5 ppm for the packed column test method and
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 3 ppm for the capillary test method.
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
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D4322 – 96 (2001)
6. Interferences 7.2.2 Capillary Column Analysis—Quadrex 007-2, 25
m 3 0.32-mm internal diameter fused silica, coated with a
6.1 The nitrogen-specific detector eliminates interference
5-µm film of 5 % phenyl/95 % methylsilicone liquid phase.
from all but compounds containing nitrogen or phosphorus.
Any such material eluting at or near the AN or PN retention
NOTE 6—Other column packings may be used after suitable evaluation
times will cause erroneous RAN results. The headspace above
to determine that no interfering peaks elute at the AN or PN retention
times. If column packings other than those listed in 7.2 are used, then the
a polymer solution containing no internal standard should be
settings recommended in Sections 11 and 12 may have to be modified.
analyzed to determine that no sample peaks coincide with the
PN retention time for the packed column test method. The
7.3 Recorder, 5-mV full-scale or computing integrator, or
capillarycolumntestmethodspecifiesuseofaflameionization
appropriate computer data station and software.
detector. It is an external standard test method, therefore,
7.4 Vial Sealer, for vials.
concern with sample peaks coinciding with the retention time
7.5 Analytical Balance, capable of weighing to 60.0001 g.
of the internal standard peak is not an issue.
7.6 Pressure Regulators, for all required gas cylinders.
6.2 Normallytheheadspacewillcontainonlyair,RAN,PN,
7.7 Filter-Drier Assemblies, for each required GC gas
water, solvent, and any other volatile compounds used during
cylinder.
polymerization. Such impurities at concentrations of 0 to 100
7.8 Soap Film Flowmeter, if the gas chromatograph used is
ppm will have negligible effect on the equilibrium relationship
not capable of electronic flow programming.
upon which this test method is based.
8. Reagents and Materials
7. Apparatus
8.1 Purity of Reagents—Reagent grade chemicals shall be
7.1 Gas Chromatograph, equipped with nitrogen-
used in all tests. Unless otherwise stated, it is intended that all
phosphorus specific detector, and backflush valve, that is
reagents shall conform to the specifications of the Committee
capable of automatically and sequentially sampling and ana-
on Analytical Reagents of the American Chemical Society,
lyzing the headspace vapors contained in sealed vials. 7
where such specifications are available. Other grades may be
7.1.1 If packed column analysis is preferred, the gas chro-
used provided it is first ascertained that the reagent is of
matography should be equipped with a packed column inlet, a
sufficiently high purity to permit its use without lessening the
nitrogen-phosphorous specific detector, and a backflush valve.
accuracy of the determination.
8.2 Acrylonitrile Standard.
NOTE 2—The Perkin-Elmer Model HS40XL Headspace Autosampler
coupled with a Perkin-Elmer AutoSystem XL Gas Chromatograph can 8.3 Internal Standard,propionitrile(PN)forpackedcolumn
fulfill these requirements.
analysis.
8.4 N, N-Dimethylacetamide (DMAC) or Propylene Car-
7.1.2 If capillary column analysis is preferred, the gas
bonate (PC) are suitable solvents for the packed column test
chromatograph should be equipped with a capillary column
method, and o-Dichlorobenzene is suitable for the capillary
inlet, and a flame ionization detector.
column test method.
NOTE 3—The Hewlett-Packard Model HP7694 Headspace Sampler
NOTE 7—A solvent blank headspace must be chromatographed to
coupled with a Hewlett-Packard Model HP6890 Gas Chromatograph can
ensure the absence of interferences at the AN or PN retention times.
fulfill these requirements.
NOTE 4—Another suitable detector may be utilized (for example,
8.5 Hydrogen Cylinder, prepurified.
nitrogen-phosphorus specific detector), however, the operating procedures
8.6 Helium or Nitrogen Cylinder, prepurified.
in Section 12 would have to be altered to suit the equipment used.
NOTE 5—If “manual” analysis is to be performed (that is, syringe
NOTE 8—Either nitrogen or helium may be used as the carrier gas for
injection into other chromatographs), then the following additional equip-
the packed column test method. The capillary test method is written for
ment is needed.
usewithheliumasthecarriergas.Nitrogenmaybesubstitutedforhelium,
(1) Constant-Temperature Bath, capable of maintaining 90 6 1°C. however, the number of effective theoretical plates may be altered. It may
be necessary to adjust the head pressure and column flow to obtain
(2) Gastight Gas Chromatographic Syringes for sampling and injec-
comparable chromatographic peak retention times.
tion.
(3) Septa, Butyl Rubber, and Aluminum Vial Seals, if headspace vials
8.7 Air, breathing or water-pumped.
are used.
8.8 Certified, low-residual ABS, SAN, or nitrile rubber
(4) Valve, 6-port for backflush.
material of known AN concentration to be used as a standard
7.2 Chromatographic Columns:
for the capillary column test method or combination thereof.
7.2.1 Packed Column Analysis—80/100-mesh Chromosorb
101 or 0.2 % Carbowax 1500/Carbopack C (80/100), 3.2-mm
outside diameter by 1 m and 3.2-mm outside diameter by 2 m,
ColumnavailablefromQuadrexCorp.,P.O.Box3881,Woodbridge,CT06525.
stainless steel.
Reagent Chemicals, American Chemical Society Specifications, American
Chemical Society, Washington, DC. For suggestions 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
Available from Perkin-Elmer Corp., 761 Main Ave., Norwalk, CT 06859. and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,
Agilent Technologies, P.O. Box 10395, Palo Alto, CA 94303. MD.
5 8
Column packing available from Supelco, Inc., Supelco Park, Bellefont, PA AvailablefromScientificPolymerProducts,Inc.,6265DeanParkway,Ontario,
16823-0048. NY 14519.
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D4322 – 96 (2001)
9. Safety Precautions 11. Preparation of Gas Chromatograph for Packed
Column Analysis
9.1 Do not release acrylonitrile to the laboratory atmo-
sphere. Prepare standards and handle samples in a well-
NOTE 9—All conditions outlined in this section refer to the Perkin-
ventilated hood. Dimethylacetamide and o-dichlorobenzene
Elmer Model HS40XL Headspace Autosampler and Perkin-Elmer Auto-
are absorbed through the skin, so avoid contact.
System XL Gas Chromatograph. If equivalent equipment is used or if
9.2 Be careful not to come into contact with heated chro-
analyses are performed “manually,” then alter operating procedures to suit
matographic parts such as the detector, column, rotating
equipment used.
sample tray, hot sample vials, etc. involving manual injections
11.1 Connect 1 m and 2-m chromatographic columns with a
(see Note 4). Once heated, sample vials are under pressure.
low dead volume “tee.” Install in the chromatograph oven with
After analysis, vent the pressure with a hypodermic syringe
a1-mlengthconnectedtotheinjectionportandthe“tee”outlet
needle into a charcoal slug or vent tube leading to a hood
attached to the backflush exit port. Do not connect the exit end
before removing vials from the water bath.
of the column to the detector.
10. Sampling and Storage
NOTE 10—Formanualinjections,onemethodofachievingbackflushof
10.1 Keep all samples in tightly sealed jars.Analyze sample
the solvent is shown schematically in Fig. 1. For this backflush mode,
solutionswithin24h.If24hareexceeded,reporttheageofthe
connect a 3-m column to the valve ports as shown. Attach an auxiliary
sample solution.
FIG. 1 Typical 6-Port Valve Backflush Assembly
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D4322 – 96 (2001)
carriergaslineandventlinetotheappropriatevalveports.The“B”carrier
12.3.2 Total Flow—25 mL/min (includes flow from head-
gas line of dual-injector instruments is a convenient source for this
space unit).
auxiliary flow.
12.3.3 Septum Purge Rate—2 to 3 mL/min.
11.2 Adjust the carrier gas flow to 25 to 35 mL/min that is 12.4 Condition column overnight at 250°C. Hydrogen and
optimum for minimum peak broadening consistent with fast air to the detector should be turned off while the column is
analysis time. Use this flow rate for both the analysis and conditioning.
backflush mode. If electronic flow programming is not avail- 12.5 Connect the column to the detector inlet and set the
able, adjust the carrier gas pressure and use a soap film
flame ionization detector gas flows as follows:
flowmeter to measure column flow.
12.5.1 Hydrogen—Approximately 40 mL/min.
12.5.2 Air—Approximately 300 mL/min.
NOTE 11—For the manual injection backflush system shown in Fig. 1,
12.5.3 Make-Up Gas—Approximately 40 mL/min.
switch the valve to the VENT position. Adjust the auxiliary flow at the
vent port to the same rate as established in 11.2.
12.6 Set the instrument temperatures as follows:
NOTE 12—Switch the valve to the VENT position to begin backflush 1
12.6.1 Injection Port—200°C.
min after elution of the internal standard peak. Backflush should be four
12.6.2 Detector—250°C.
times as long as the forward flow time. Vent backflushed products into a
12.6.3 Oven—60°C for 5 min, 10°C/min to 140°C, hold for
hood.
3 min, 3°C/min to 200°C.
11.3 Condition the column overnight at 200°C. Hydrogen
12.7 Set the headspace analyzer parameters as follows:
and air to the detector should be turned off while the column is
12.7.1 Carrier Pressure—0.9 bar.
conditioning.
12.7.2 Auxiliary Pressure—1.0 bar.
11.4 Set the detector air flow and pressure at the optimum
12.7.3 Servo Pressure—4.0 bar.
conditions for the make and model of the chromatograph being
12.7.4 Heated Sample Zone Temperature—90°C.
used.
12.7.5 Loop Temperature—95°C.
11.5 Setthedetectorbeadhydrogenflowandpressureatthe
12.7.6 Equilibrium Time—1 h.
optimum conditions for the make and model of the chromato-
12.7.7 Sample Loop Volume—3 mL.
graph being used.
12.7.8 Timetable of Events:
NOTE 13—As a general rule, the lowest bead temperature that will
12.7.8.1 Pressure Start—03 s,
produce adequate sensitivity should be used. By turning the bead setting
12.7.8.2 Pressure Stop—13 s,
off or to 2.5 between usages, bead life will be prolonged.
12.7.8.3 Fill Loop Start—23 s,
11.6 Set temperatures as follows:
12.7.8.4 Fill Loop Stop—33 s,
11.6.1 Chromatograph Oven (Column)—130°C.
12.7.8.5 Injection Start—34s,and
11.6.2 Dosing Needle—150°C.
12.7.8.6
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