ASTM D4509-96
(Test Method)Standard Test Methods for Determining the 24-Hour Gas (AIR) Space Acetaldehyde Content of Freshly Blown PET Bottles (Withdrawn 2005)
Standard Test Methods for Determining the 24-Hour Gas (AIR) Space Acetaldehyde Content of Freshly Blown PET Bottles (Withdrawn 2005)
SCOPE
1.1 These test methods cover the 24-h gas-space acetaldehyde (AA) content of freshly blown polyethylene terephthalate (PET) bottles.
1.2 These test methods, containing internal or external standard calibration, are applicable to all PET bottles.
1.3 The values stated in SI units are to be regarded as the standard.
Note 1- These is no similar or equivalent ISO standard.
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.
WITHDRAWN RATIONALE
These test methods covered the 24-h gas-space acetaldehyde (AA) content of freshly-blown polyethylene terephthalate (PET) bottles.
These test methods were withdrawn in December 2004 in accordance with section 10.5.3.1 of the Regulations Governing ASTM Technical Committees, which requires that standards shall be updated by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
Relations
Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Please contact ASTM International (www.astm.org) for the latest information.
Designation:D4509–96
Standard Test Methods for
Determining the 24-Hour Gas (AIR) Space Acetaldehyde
Content of Freshly Blown PET Bottles
This standard is issued under the fixed designation D4509; 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 (ϵ) indicates an editorial change since the last revision or reapproval.
1. Scope 3. Terminology
1.1 These test methods cover the 24-h gas-space acetalde- 3.1 The gas chromatographic terms employed in these test
hyde(AA)contentoffreshlyblownpolyethyleneterephthalate methods are those recommended by Practice E355E355.
(PET) bottles. 3.2 Units, symbols, and abbreviations used in these test
1.2 These test methods, containing internal or external methods are those recommended by Practice E380E380.
standard calibration, are applicable to all PET bottles. 3.3 For further information on abbreviation, PET, refer to
1.3 The values stated in SI units are to be regarded as the Terminology D1600D1600.
standard. 3.4 Additional terms relative to plastics are explained in
Terminology D883D883.
NOTE 1—There is no similar or equivalent ISO standard.
4. Summary of Test Methods
1.4 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
4.1 Amolded preform (any size) is blown into a bottle that
responsibility of the user of this standard to establish appro-
is purged with nitrogen, capped, and aged. After 24 h, a
priate safety and health practices and determine the applica-
headspace gas sample is taken from the bottle, and the gas
bility of regulatory limitations prior to use.
sample is injected into a gas chromatograph for comparison
with known external standards (Sections 9-11) or internal
2. Referenced Documents
standards (Sections 12-14).
2.1 ASTM Standards:
D883 Terminology Relating to Plastics 5. Significance and Use
D1193 Specification for Reagent Water
5.1 Before proceeding with these test methods, reference
D1600 Terminology for Abbreviated Terms Relating to
shouldbemadetothespecificationofthematerialbeingtested.
Plastics
Any test specimens preparation, conditioning, dimensions, and
E177 Practice for Use of the Terms Precision and Bias in
testing parameters covered in the materials specification, shall
ASTM Test Methods
take precedence over those mentioned in these test methods. If
E355 Practice for Gas Chromatography Terms and Rela-
there is no material specification, then the default conditions
tionships
apply.
E380 Practice for Use of the International System of Units
5.2 Acetaldehyde is a decomposition product of the poly-
(SI) (the Modernized Metric System)
condensationreactionandisaby-productofmeltprocessingof
E691 Practice for Conducting an Interlaboratory Study to
polyethylene terephthalate (PET). It adds undesirable flavor to
Determine the Precision of a Test Method
some beverages.
5.3 The level of acetaldehyde in PET blown containers is
1 monitored by these test methods.
These test methods are under the jurisdiction of ASTM Committee D20 on
Plastics and are the direct responsibility of Subcommittee D20.70 on Analytical
6. Apparatus
Methods (Section D20.70.03).
This standard has been reviewed and the following items added: an ISO
6.1 Gas Chromatograph, with flame ionization detector,
equivalencystatement;amaterialspecificationreferencestatement;andaKeywords
equipped with a six-port gas-sampling valve and a 5-mL
Section.
Current edition approved August 10, 1996. Published February 1997. gas-sampling loop for sampling the headspace of the beverage
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
bottle, as shown in Fig. 1.
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
6.2 Any suitable system of peak integration can be used for
Standards volume information, refer to the standard’s Document Summary page on
measurement of the acetaldehyde.
the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Please contact ASTM International (www.astm.org) for the latest information.
D4509–96
FIG. 1 Schematic Drawing of Gas-Sampling Apparatus
6.3 Gas Sampling Apparatus as shown in Fig. 1, including: 7.2 Acetaldehyde Standard Solution, prepared and analyzed
6.3.1 Trap, 25.4 mm (1 in.) outside diameter by 0.305 m (1 by the procedure described in Annex A1.
ft) long containing 1 part silica-gel absorbant and 1 part 5A
7.3 Acetaldehyde/Propionaldehyde Standard Solution, pre-
molecular-sieve packing.
pared by Annex A2 (internal standard method only).
6.3.2 Pressure-Vacuum Gage, 0–30 psig and 30 in. Hg.
7.4 Phenolic Polymer Bottle Cap, 28 mm outside diameter,
6.4 Gastight GC Syringe,10µL.
containinga6.35-mm( ⁄4-in.)holedrilledinthetopandsnugly
6.5 Gastight GC Syringe, 0 to 5.0 cc (internal standard
fitted with a seal cut from 1.59-mm ( ⁄16-in.) butyl rubber and
method only).
lined with a liner cut from 0.08-mm (0.003-in.) fluoropolymer
filmtopreventabsorptionofacetaldehydeintothebutylrubber
7. Reagents and Materials
seal.
7.1 A 2.0 m by 6 mm outside diameter, 4-mm inside
diameter glass column, packed with Porapak Q or QS (100 to NOTE 2—The phenolic caps and the butyl rubber seals may be reused
after the test, but the fluoropolymer liner must be discarded after it is
120mesh)porouspolymerorTenaxGCporouspolymer(60to
punctured.
80 mesh), packed into a 3.2 or 3.18 mm ( ⁄8 in.) outside
diameter by 3.66 m (12 ft) long stainless-steel tube.
7.5 Nitrogen (oxygen-free) or helium (GC).
7.6 Hydrogen, prepurified or zero-gas.
7.7 Air, breathing, water-pumped.
PoropakisaregisteredtrademarkofWatersAssociates,Inc.,Framingham,MA.
7.8 Acetaldehyde, reagent-grade (internal standard method
Tenax is a registered trademark of Enka Glanzstoff B.V. of Arnhem, Netherlands.
Both polymers are available from laboratory supply houses. only).
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Please contact ASTM International (www.astm.org) for the latest information.
D4509–96
7.9 Propionaldehyde, reagent-grade (internal standard 9.2.8 Allowthepressureinthesamplelooptore-equilibrate
method only). to atmospheric pressure, as indicated by a mark on the gage.
7.9.1 High-purity 1-propanol, distilled in glass (internal 9.2.9 Close toggle Valve A and remove the bottle from the
standard method only). sample needle.
7.10 Purity of Reagents—Reagent grade chemicals shall be 9.2.10 Switch the six-port gas-sampling valve to flush the
usedinalltests.Allreagentsshallconformtothespecifications sample loop onto the column packing and simultaneously start
of the committee on Analytical Reagents of the American the data-acquisition system.
Chemical Society where such specifications are available. 9.2.11 After the integration of the acetaldehyde peak is
complete, switch the six-port valve pack to the sampling
8. Conditioning
position.
9.2.12 Open toggleValve B to evacuate the sample loop for
8.1 Purge the PET bottles for approximately 20 s with a
the next determination.
stream (1 L/s) of dry nitrogen within a maximum of 1 h after
the bottles are blown.
10. Calculations for External Calibration Test Method
8.2 Cap the bottles after purging them.
10.1 The calculation of the gas-space acetaldehyde concen-
8.3 Storethebottlesat24 61hat21.5 61.5°C(72 63°F).
tration in the test bottles is as follows:
9. Procedure for External-Calibration Test Method
Acetaldehydeconcentration ~inµg/Lgasspace!5 F 3 A (1)
a
9.1 Operate the gas chromatograph according to the follow-
where:
ing conditions:
A = area of acetaldehyde peak in the sample, and
a
9.1.1 Optimize the air and hydrogen flow rates to the flame
F = µg/L (AA in calibration standard)/Area counts in
ionizationdetectoraccordingtothemanufacturer’srecommen-
calibration standard.
dations.
9.1.2 Optimize the carrier gas-flow rate.
11. Calibration for External Standard Test Method
9.1.3 Set the GC oven-temperature controller at an isother-
11.1 The calibration is similar to the procedure except that
mal temperature that will result in a retention time of at least 2
the calibration standard gas mixture is prepared in a glass
min about 140°C (284°F) for columns packed with Poropak Q
bottle.
or QS porous polymer or 110°C (230°F) for columns packed
11.2 Obtain a glass-bottle known volume (approximately 1
with Tenax GC porous polymer.
L).
9.1.4 Turn on the vacuum pump.
11.3 Insert eight to ten 2-mm glass beads into the glass
9.1.5 Prepare to integrate the area of acetaldehyde and to
bottle.
report the concentration in µg/L.
11.4 Followthesamplepreparationdescribedin8.1and8.2.
9.2 Determine the acetaldehyde in the gas space of a
11.5 Inject a sample from the bottle used for the calibration
conditioned beverage bottle as follows (refer to Fig. 1):
into the gas chromatograph to ensure a satisfactory blank
9.2.1 Close toggle Valve A and open toggle Valve B to
response with no acetaldehyde or other interference.
evacuate the sample loop.
11.6 Witha10-µLsyringe,inject4µLofastandardsolution
9.2.2 Close toggleValve B and observe the vacuum gage to
of acetaldehyde in water at a concentration of approximately 1
determine if there are any leaks in the system.
mg/mL through the seal of the glass bottle. The concentration
9.2.3 Ifleaksarepresent,determinethecauseandeliminate
of the acetaldehyde solution and the volume of the glass bottle
them.Then begin again at 9.2.1. If there are no leaks, continue
must be accurately known.
with 9.2.4.
11.7 Thoroughlyshaketheglassbottlewithglassbeadsinit
9.2.4 Take the bottle obtained in Section 8 and push the
to ensure mixing of the acetaldehyde solution with the dry
sample needle through the hole in the phenolic polymer cap,
nitrogen. Condition the bottle at room temperature for 30 min
piercing the butyl rubber gasket and the fluoropolymer liner.
to1hto allow it to come to equilibrium.
9.2.5 In order to purge air from the system, quickly open
11.8 Follow the procedure in 9.2.1-9.2.12 in triplicate.
and close toggle Valve A once.
11.9 Calibrate the instrument using the average area count
9.2.6 Open toggle Valve B for approximately 30 s to
from the three injections.
evacuate the sample loop.
9.2.7 ClosetoggleValveBandopentoggleValveAtoallow
12. Procedure for Internal Standardization Test Method
the sample loop to fill with sample.
12.1 Operate the gas chromatograph according to the con-
NOTE 3—The procedures in 9.2.5, 9.2.6, and the first part of 9.2.7 ditions outlined in 9.1.1, 9.1.2, and 9.1.3.
(“close toggle Valve B”) may be eliminated if the first sample from a
12.2 Using 10-µL syringe, inject an 8 µL, 0.5% propional-
bottle is discarded.
dehyde(internalstandard)in1-propanolsolutionintotheinner
volumeofthe2-Lbottle,andallowtovaporize(approximately
15 to 30 min). If bottle capacity differs from 2 L, adjust the
“ReagentChemicals,AmericanChemicalSocietySpecifications,”Am.Chemi-
internal standard accordingly, for example, for 1-L bottle use
cal Soc., Washington, DC. For suggestions on the testing of reagents not listed by
4.0 µL internal standard solution, etc.
theAmericanChemicalSociety,see“ReagentChemicalsandStandards,”byJoseph
12.3 Place the bottle in a 50°C (122°F) oven for 10 to 15
Rosin, D. Van Nostrand Co., Inc., New York, NY, and the “United States
Pharmacopeia.” min to thermally mix the gases.
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Please contact ASTM International (www.astm.org) for the latest information.
D4509–96
12.4 Remove a 5.0-mL aliquot with the gas syringe after
where:
pushing the syringe needle through the hole in the phenolic
A = area of acetaldehyde peak,
a
polymer cup, piercing the butyl rubber gasket and the fluo- A = area of propionaldehyde peak,
p
S = internal standard, µL,
ropolymer liner. Lock the syringe and withdraw it from the
R = relative response factor (weight percent/
f
bottle.
area percent of acetaldehyde relative to
12.5 Pressurize the locked syringe to 1.25 mL (approxi-
propionaldehyde taken as 1.00),
mately 60 psi).
W = weight fraction of propionaldehyde in in-
p
12.6 Insert the syringe into the gas chromatograph, unlock
ternal standard solution,
thesyringevalve,displacethecontentsrapidly,andremovethe
0.834 310 = density of propionaldehyde internal stan-
syringe.
dard solution at−30°C (−22°F), µg/L, and
V = volume of bottle interior, mL.
12.7 Prime the syringe 3 to 5 times in air to prepare the
syringe for the next determination.
14. Calibration for Internal Standard Test Method
13. Calculations for Internal Calibration Test Method 14.1 Prepare a calibration mixture containing acetaldehyde
and propionaldehyde in 1-propanol according to A2.1.
13.1 From the peak areas of acetaldehyde and propionalde-
14.2 Prepareaninternalstandardsolutionforadditiontothe
hyde, calculate the weight of acetaldehyde in terms of micro-
sample according to A2.2.
grams per litres of interior bottle volume from:
14.3 Conduct calibration for the determination of acetalde-
hyde diffused from bottle polymer into the headspace as
A ~R ! ~0.834! ~10 ! W S
a f p
Acetaldehyde,µg/L 5 (2)
A ~V! follows:
p
Acetaldehyde, Acetaldehyde, Propionaldehyde,
A
Propionaldehyde, Weight, % R
F
Weight, % Area Counts Area Counts
0.560 0.500 4325 5155 1.33
4144 4888 1.32
A
R = weight percent/area percent response factor; propionaldehyde taken as 1.00.
F
FIG. 2 Chromatogram of Calibration Solution
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Please contact ASTM International (www.astm.org) for the latest information.
D4509–96
14.3.1 Remove the calibration mixture from the freezer, 15.8 Age of the preform before blowing.
shake, and replace the cap with a fresh cap. 15.9 Time between bottle blow molding and capping.
14.3.2 Prime the 10-µL syringe and withdraw a 4-µL ali-
16. Precision and Bias
quot.
16.1 This precision statement is based on a round robin
14.4 Injectthealiquotintoaglass1-L(32-oz)bottle(aglass
conducted in 1979 by five laboratories analyzing PET bottles
carbonated beverage bottle is suitable) and immediately stop-
blown by the laboratories, under slightly different conditions
per with a septum cap lined with fluoropolymer film.
from comparisons that were obtained from the same sample of
14.5 Allow the calibration solution to evaporate in the
material. Each laboratory made from six to twelve determina
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