SIST-TS CEN/TS 13130-26:2005
(Main)Materials and articles in contact with foodstuffs - Plastics substances subject to limitation - Part 26: Determination of 1-octene and tetrahydrofuran in food simulants
Materials and articles in contact with foodstuffs - Plastics substances subject to limitation - Part 26: Determination of 1-octene and tetrahydrofuran in food simulants
This document, part of EN 13130, specifies analytical procedures for the determination of 1-octene and THF in food simulants water, 3 % w/v aqueous acetic acid, 15 % v/v aqueous ethanol and olive oil. The level of 1-octene and THF monomer determined is expressed as milligrams of monomer per kilogram of food simulant. The methods are appropriate for the quantitative determination of 1-octene in the range of 2 mg/kg to 30 mg/kg in food simulants and of THF in the range of 0,06 mg/kg to 1,5 mg/kg in food simulants.
NOTE The method should also be applicable to other aqueous food simulants as well as to the other fatty food simulants e.g. sunflower oil, corn oil or a mixture of synthetic triglycerides.
Werkstoffe und Gegenstände in Kontakt mit Lebensmitteln - Substanzen in Kunststoffen, die Beschränkungen unterliegen - Teil 26: Bestimmung von 1-Octen und Tetrahydrofuran in Prüflebensmitteln
Diese Technische Spezifikation, Teil der EN 13130, legt Analyseverfahren zur Bestimmung von 1 Octen und THF in den Prüflebensmitteln Wasser, 3%ige Essigsäure (m/V) in wässriger Lösung, 15%iges Ethanol (Volumenanteil) in wässriger Lösung und Olivenöl fest. Der ermittelte Gehalt an monomerem 1 Octen und THF wird in Milligramm Monomer je Kilogramm Prüflebensmittel angegeben. Die Verfahren eignen sich zur quantitativen Bestimmung von 1 Octen im Bereich von 2 mg/kg bis 30 mg/kg Prüflebensmittel und von THF im Bereich von 0,06 mg/kg bis 1,5 mg/kg Prüflebensmittel.
ANMERKUNG Das Verfahren sollte auch auf andere wässrige Prüflebensmittel sowie weitere fettige Prüflebensmittel, z. B. Sonnenblumenöl, Maiskeimöl oder eine Mischung synthetischer Triglyceride, anwendbar sein.
Matériaux et objets en contact avec les denrées alimentaires - Substances dans les matieres plastiques soumises a des limitations - Partie 26 : Détermination du 1-octene et du tétrahydrofurane dans les simulants d'aliments
Ce document, qui fait partie de l'EN 13130, spécifie des modes opératoires d'analyse pour la détermination du 1 octene et du THF dans les quatre simulants d'aliments suivants : eau, solution aqueuse d'acide acétique a 3 % (m/v), solution aqueuse d'éthanol a 15 % (v/v) et huile d'olive. La teneur en 1 octene est exprimée en milligrammes de monomere par kilogramme de simulant d'aliments. Ces méthodes conviennent pour la détermination quantitative du 1 octene pour une concentration comprise entre 2 mg et 30 mg par kilogramme de simulant d'aliments et pour la détermination quantitative du THF pour une gamme de concentrations comprises entre 0,06 mg et 1,5 mg par kilogramme de simulant d'aliments.
NOTE Il convient que la méthode puisse également etre appliquée a d'autres simulants aqueux ainsi qu'a des simulants gras tels que l'huile de tournesol ou un mélange de triglycérides.
Materiali in predmeti v stiku z živili - Snovi v polimernih materialih, katerih koncentracija je omejena - 26. del: Določevanje 1-oktena in tetrahidrofurana v modelnih raztopinah za živila
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
SIST-TS CEN/TS 13130-26:2005
01-april-2005
0DWHULDOLLQSUHGPHWLYVWLNX]åLYLOL6QRYLYSROLPHUQLKPDWHULDOLKNDWHULK
NRQFHQWUDFLMDMHRPHMHQDGHO 'RORþHYDQMHRNWHQDLQWHWUDKLGURIXUDQDY
PRGHOQLKUD]WRSLQDK]DåLYLOD
Materials and articles in contact with foodstuffs - Plastics substances subject to limitation
- Part 26: Determination of 1-octene and tetrahydrofuran in food simulants
Werkstoffe und Gegenstände in Kontakt mit Lebensmitteln - Substanzen in Kunststoffen,
die Beschränkungen unterliegen - Teil 26: Bestimmung von 1-Octen und Tetrahydrofuran
in Prüflebensmitteln
Matériaux et objets en contact avec les denrées alimentaires - Substances dans les
matieres plastiques soumises a des limitations - Partie 26 : Détermination du 1-octene et
du tétrahydrofurane dans les simulants d'aliments
Ta slovenski standard je istoveten z: CEN/TS 13130-26:2005
ICS:
67.250 Materiali in predmeti v stiku z Materials and articles in
živili contact with foodstuffs
SIST-TS CEN/TS 13130-26:2005 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST-TS CEN/TS 13130-26:2005
TECHNICAL SPECIFICATION
CEN/TS 13130-26
SPÉCIFICATION TECHNIQUE
TECHNISCHE SPEZIFIKATION
February 2005
ICS 67.250
English version
Materials and articles in contact with foodstuffs - Plastics
substances subject to limitation - Part 26: Determination of 1-
octene and tetrahydrofuran in food simulants
Matériaux et objets en contact avec les denrées Werkstoffe und Gegenstände in Kontakt mit Lebensmitteln
alimentaires - Substances dans les matières plastiques - Substanzen in Kunststoffen, die Beschränkungen
soumises à des limitations - Partie 26 : Détermination du 1- unterliegen - Teil 26: Bestimmung von 1-Octen und
octène et du tétrahydrofurane dans les simulants d'aliments Tetrahydrofuran in Prüflebensmitteln
This Technical Specification (CEN/TS) was approved by CEN on 16 December 2004 for provisional application.
The period of validity of this CEN/TS is limited initially to three years. After two years the members of CEN will be requested to submit their
comments, particularly on the question whether the CEN/TS can be converted into a European Standard.
CEN members are required to announce the existence of this CEN/TS in the same way as for an EN and to make the CEN/TS available
promptly at national level in an appropriate form. It is permissible to keep conflicting national standards in force (in parallel to the CEN/TS)
until the final decision about the possible conversion of the CEN/TS into an EN is reached.
CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,
Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia,
Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36 B-1050 Brussels
© 2005 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TS 13130-26:2005: E
worldwide for CEN national Members.
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Contents
page
Foreword. 3
Introduction . 5
1 Scope. 6
2 Normative references . 6
3 Method A – Determination of 1-octene in food simulants . 6
4 Method B – Determination of tetrahydrofuran in food simulants . 15
Bibliography . 25
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Foreword
This document (CEN/TS 13130-26:2005) has been prepared by Technical Committee CEN/TC 194
“Utensils in contact with food”, the secretariat of which is held by BSI.
This part of EN 13130 has been prepared within the Standards, Measurement and Testing project,
MAT1-CT92-0006, “Development of Methods of Analysis for Monomers” and has been prepared by
Subcommittee (SC 1) of TC 194 "Utensils in contact with food" as one of a series of test methods for
plastics materials and articles in contact with foodstuffs.
This standard is intended to support Directives 2002/72/EC [1], 89/109/EEC [2], 82/711/EEC [3] and
its amendments 93/8/EEC [4] and 97/48/EC [5], and 85/572/EEC [6].
At the time of preparation and publication of this part of EN 13130 the European Union legislation
relating to plastics materials and articles intended to come into contact with foodstuffs is incomplete.
Further Directives and amendments to existing Directives are expected which could change the
legislative requirements which this standard supports. It is therefore strongly recommended that users
of this standard refer to the latest relevant published Directive(s) before commencement of a test or
tests described in this standard.
This part of EN 13130 should be read in conjunction with EN 13130-1.
Further parts of EN 13130, under the general title Materials and articles in contact with foodstuffs -
Plastics substances subject to limitation, have been prepared, and others are in preparation,
concerned with the determination of specific migration from plastics materials into foodstuffs and food
simulants and the determination of specific monomers and additives in plastics. The parts of
EN 13130 are as follows.
Part 1: Guide to test methods for the specific migration of substances from plastics to foods and food
simulants and the determination of substances in plastics and the selection of conditions of exposure
to food simulants
Part 2: Determination of terephthalic acid in food simulants
Part 3: Determination of acrylonitrile in food and food simulants
Part 4: Determination of 1,3-butadiene in plastics
Part 5: Determination of vinylidene chloride in food simulants
Part 6: Determination of vinylidene chloride in plastics
Part 7: Determination of monoethylene glycol and diethylene glycol in food simulants
Part 8: Determination of isocyanates in plastics
Part 9: Determination of acetic acid, vinyl ester in food simulants
Part 10: Determination of acrylamide in food simulants
Part 11: Determination of 11-aminoundecanoic acid in food simulants
Part 12: Determination of 1,3-benzenedimethanamine in food simulants
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Part 13: Determination of 2,2-bis(4-hydroxyphenyl)propane (Bisphenol A) in food simulants
Part 14: Determination of 3,3-bis(3-methyl-4-hydroxyphenyl)-2-indoline in food simulants
Part 15: Determination of 1,3-butadiene in food simulants
Part 16: Determination of caprolactam and caprolactam salt in food simulants
Part 17: Determination of carbonyl chloride in plastics
Part 18: Determination of 1,2-dihydroxybenzene, 1,3-dihydroxybenzene,
1,4-dihydroxybenzene, 4,4’-dihydroxybenzophenone and 4,4’dihydroxybiphenyl in food simulants
Part 19: Determination of dimethylaminoethanol in food simulants
Part 20: Determination of epichlorohydrin in plastics
Part 21: Determination of ethylenediamine and hexamethylenediamine in food simulants
Part 22: Determination of ethylene oxide and propylene oxide in plastics
Part 23: Determination of formaldehyde and hexamethylenetetramine in food simulants
Part 24: Determination of maleic acid and maleic anhydride in food simulants
Part 25: Determination of 4-methyl-pentene in food simulants
Part 26: Determination of 1-octene and tetrahydrofuran in food simulants
Part 27: Determination of 2,4,6-triamino-1,3,5-triazine in food simulants
Part 28: Determination of 1,1,1-trimethylolpropane in food simulants
Parts 1 to 8 are European Standards. Parts 9 to 28 are Technical Specifications.
WARNING All chemicals are hazardous to health to a greater or lesser extent. It is beyond
the scope of this Technical Specification to give instructions for the safe handling of all
chemicals, that meet, in full, the legal obligations in all countries in which this Technical
Specification may be followed. Therefore, specific warnings are not given and users of this
Technical Specification should ensure that they meet all the necessary safety requirements in
their own country.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to announce this CEN Technical Specification: Austria, Belgium, Cyprus,
Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland,
Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia,
Slovenia, Spain, Sweden, Switzerland and United Kingdom.
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Introduction
1-octene, C H or CH =CH-(CH ) –CH , PM/Ref. No 22660, and tetrahydrofuran (THF), C H O,
8 16 2 2 5 3 4 8
PM/Ref. No 25150, are monomers used in the manufacture of certain plastics materials and articles
intended to come into contact with foodstuffs. After manufacture, residual monomer can remain in the
polymer and may migrate into foodstuffs coming into contact with that plastics article.
NOTE However, the following should be taken into account at carrying out a migration test for 1-octene.
From migration experiments carried out for 10 d for 40 °C it was recognized that irreproducible loss of 1-octene,
11 % to 69 %, due to volatilization, can arise when using aqueous food simulants.
Method A describes the determination of 1-octene in food simulants.
Method B describes the determination of tetrahydrofuran in food simulants.
The methods have been pre-validated by collaborative trials with two laboratories.
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1 Scope
This document, part of EN 13130, specifies analytical procedures for the determination of 1-octene
and THF in food simulants water, 3 % w/v aqueous acetic acid, 15 % v/v aqueous ethanol and olive
oil. The level of 1-octene and THF monomer determined is expressed as milligrams of monomer per
kilogram of food simulant. The methods are appropriate for the quantitative determination of 1-octene
in the range of 2 mg/kg to 30 mg/kg in food simulants and of THF in the range of 0,06 mg/kg to 1,5
mg/kg in food simulants.
NOTE The method should also be applicable to other aqueous food simulants as well as to the other fatty
food simulants e.g. sunflower oil, corn oil or a mixture of synthetic triglycerides.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
EN 13130-1:2004, Materials and articles in contact with foodstuffs – Plastics substances subject to
limitation – Part 1: Guide to test methods for the specific migration of substances from plastics to
foods and food simulants and the determination of substances in plastics and the selection of
conditions of exposure to food simulants.
3 Method A – Determination of 1-octene in food simulants
3.1 Principle
The level of 1-octene in a food or a food simulant is determined by headspace gas chromatography
(HSGC) of the food simulant sample, sealed in headspace glass vials. Headspace gas
chromatography is carried out applying automatic injection and flame ionization detection.
Quantification is achieved using iso-octane as internal standard with calibration against food simulant
samples fortified with known amounts of 1-octene. Confirmation of 1-octene levels is carried out by
combined gas chromatography/mass spectrometry (GC/MS).
3.2 Reagents
NOTE All reagents should be of recognized analytical quality unless otherwise stated.
3.2.1 Analytes
3.2.1.1 1-octene, CH =CH-(CH ) –CH , purity greater than 97,5 % (GC).
2 2 5 3
3.2.1.2 Iso-octane, (CH ) -CH-CH -C(CH ) , purity greater than 99 % (GC).
3 2 2 3 3
3.2.2 Chemical
N,N-dimethylacetamide (DMAA), CH -CO-N(CH ) , purity greater than 99 %.
3 3 2
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3.2.3 Solutions
3.2.3.1 Stock solutions of 1-octene with a defined concentration of approximately 2 mg/ml in
DMAA
Weigh a 50 ml volumetric flask, including cap, filled with about 45 ml of DMAA (3.2.2), to an accuracy
of 0,1 mg. Add approximately 100 mg of 1-octene (about 150 µl), then reweigh to an accuracy of
0,1 mg. Make up to 50 ml with DMAA. Close and shake.
Calculate the exact concentration of the stock solution in milligrams of 1-octene per millilitre of
solution.
Repeat the procedure to provide a second stock solution.
NOTE These stock solutions can be stored at + 4 °C, with the exclusion of light, for up to 3 months.
3.2.3.2 Standard solutions of 1-octene in DMAA with a defined concentration of
approximately 200 µg/ml
Place 1,0 ml of the 1-octene stock solution (3.2.3.1) in a 10 ml volumetric flask and make up to the
mark with DMAA (3.2.2). Close and mix thoroughly.
Calculate the exact concentration of the standard solution in milligrams of 1-octene per millilitre of
solution.
Repeat the procedure using the second stock solution prepared in 3.2.3.1 to provide a second
standard solution.
NOTE These standard solutions can be stored at + 4 °C and with the exclusion of light for up to 3 months.
3.2.3.3 Stock solution of internal standard iso-octane in DMAA at a defined concentration of
approximately 2 mg/ml
Weigh a 50 ml volumetric flask, including cap, filled with about 45 ml of DMAA (3.2.2), to an accuracy
of 0,1 mg. Add approximately 100 mg of iso-octane (about 150 µl), then reweigh to an accuracy of
0,1 mg. Make up to the mark with DMAA close and mix.
Calculate the exact concentration of the stock solution in milligrams of iso-octane per millilitre of
solution.
NOTE This stock solution can be stored at + 4 °C, with the exclusion of light, for up to 3 months.
3.2.3.4 Internal standard solution of iso-octane in DMAA at a defined concentration of
approximately 120 µg/ml
Place 3,0 ml of internal standard stock solution (3.2.3.3) in a 50 ml volumetric flask and make up to
the mark with DMAA. Close and mix thoroughly.
Calculate the exact concentration of the internal standard solution in milligrams of iso-octane per
millilitre of solution.
NOTE This internal standard can be stored at + 4 °C, with the exclusion of light, for up to 3 months.
3.3 Apparatus
NOTE An instrument or item of apparatus is listed only where it is special or made to a particular
specification, the usual laboratory glassware and equipment being assumed to be available.
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3.3.1 Gas chromatograph, equipped with a flame ionization detector (FID) and fitted with an
automatic headspace sampler.
3.3.2 Gas chromatographic column, capable of the separation of DMAA from 1-octene and iso-
octane, such that the peaks of 1-octene and iso-octane do not overlap by more than 1 % peak area
with other compounds.
NOTE The following are examples of GC columns known to be suitable for 1-octene analysis:
a) 50 m x 0,53 mm i.d. fused silica capillary column, coated with a phenyl-methyl silicone phase, film thickness
2,5 µm.
For guidance, the operating conditions established for the column described above, were the following:
Headspace sampler:
Sample thermostatting time: 80 min
Sample temperature: 70 °C
Transfer line temperature: 130 °C
Needle temperature: 85 °C
Pressure equilibration time: 3 min
Injection time: 6 sec
Gas chromatograph:
Injector: 150 °C
Detector: 220 °C
Oven program: 110 °C (11 min), 10 °C/min to 150 °C (5 min)
Carrier gas: Nitrogen at 250 kPa
Linear velocity: 35 cm/sec
Injection mode: total injection
FID gases: to be optimized according to the manufacturer's
specification
Alternatively, the following system has been found to be suitable:
b) Column: 30 m x 0,2 mm i.d. fused silica capillary column, coated with a 5 % diphenyl and 95 % dimethyl
silicone phase, film thickness 0,33 µm
Headspace sampler:
Sample thermostatting time: 60 min
Sample temperature: 100 °C
Gas chromatograph:
Carrier gas: Helium at 90 kPa and 1 ml/min
Oven program: 75 °C (8 min), 25 °C/min to 250 °C (5 min)
Injection mode: split (ratio 1:5)
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3.3.3 Glass sample vials, 20 ml or another size suitable for the particular autosampler employed,
with polytetrafluroethylene (PTFE) coated butyl or silicone rubber septa and aluminium crimp-cap
closures.
3.3.4 Volumetric flasks, 50 ml and 10 ml.
3.3.5 Microsyringes, 250 µl and 100 µl.
3.3.6 Volumetric pipettes, 1 ml and 3 ml.
3.4 Samples
3.4.1 General
Laboratory samples of the food simulant to be analyzed shall be obtained as described in
EN 13130-1. Samples shall be kept refrigerated at 4 °C in closed containers. Analyte-free samples of
relevant food simulants of the same type as those to be analyzed shall also be prepared for
calibration purposes.
Take into account the possible loss of analyte due to volatilization in aqueous food simulants (see
NOTE in the Introduction).
3.4.2 Test sample preparation
3.4.2.1 Aqueous food simulants
Place 1,0 ml of the food simulant obtained from the migration experiment into a sample vial (3.3.3)
using a volumetric pipette (3.3.6), close immediately the vial with a septum and cap. Add 200 µl iso-
octane internal standard solution (3.2.3.4) followed by 200 µl DMAA (3.2.2) to the food simulant by
injection through the septum using the 250 µl microsyringe (3.3.5).
Prepare each test sample at least in duplicate.
3.4.2.2 Olive oil
Weigh 1,0 g ± 0,01 g of the food simulant, as obtained from the migration experiment into a sample
vial (3.3.3). Close the vial immediately with a septum and cap. Add 200 µl iso-octane internal standard
solution (3.2.3.4) followed by 200 µl DMAA (3.2.2) to the olive oil test sample by injection through the
septum using the 250 µl microsyringe (3.3.5) and mix thoroughly.
Prepare each test sample at least in duplicate.
3.4.3 Blank sample preparation
3.4.3.1 Aqueous food simulants
Place 1,0 ml of aqueous 1-octene-free food simulant into a sample vial (3.3.3) using a 1,0 ml
volumetric pipette (3.3.6), then cap immediately. Add 200 µl iso-octane internal standard solution
(3.2.3.4) followed by 200 µl of DMAA (3.2.2) through the septum using the 250 µl microsyringe (3.3.5).
Prepare each blank sample at least in duplicate.
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3.4.3.2 Olive oil
Weigh 1,0 g ± 0,01 g of 1-octene-free olive oil into a sample vial (3.4.3). Cap immediately. Add 200 µl
iso-octane internal standard solution (3.2.3.4) followed by 200 µl of DMAA (3.2.2) through the septum
using the 250 µl microsyringe (3.3.5) and mix thoroughly.
Prepare each blank sample at least in duplicate.
3.4.4 Preparation of calibration samples
3.4.4.1 General
Calibration shall be obtained from at least five levels. The concentration range of calibration solutions
solution shall span from approximately 2,0 mg to 30 mg 1-octene per kilogram of food simulant.
3.4.4.2 Aqueous food simulants
Place 1,0 ml of aqueous 1-octene-free food simulant into a series of six sample vials (3.3.3) using a
1,0 ml volumetric pipette, then cap immediately. Add to each vial 200 µl of iso-octane internal
standard solution (3.2.3.4) through the septum using the 250 µl microsyringe (3.4.5) and mix
thoroughly. Add through the septum into the vial the volumes of 1-octene standard solution (3.2.3.2)
and DMAA (3.2.2) given in Table 1, using appropriate microsyringes (3.3.5).
Table 1 — Volumes of 1-octene and DMAA in calibration samples
Calibration Addition of 1-octene Addition of DMAA Approximate
sample standard solution (3.2.2) in µl concentration of 1-
(3.2.3.2) in µl octene in the
calibration sample
mg/kg
1 10 190 2
2 50 150 10
3 75 125 15
4 100 100 20
5 150 50 30
Prepare each calibration sample at least in duplicate.
Calculate the exact concentrations of the calibration samples in micrograms of 1-octene added per
millilitre of aqueous food simulant, which corresponds to milligrams per kilogram of aqueous food
simulant.
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NOTE Commission Directive 2002/72/EC [1] states that the specific gravity of all simulants should
conventionally be assumed to be ‘1’. Milligrams of substance released per litre of simulant will thus correspond
numerically to milligrams of substance released per kilogram of simulant and, taking into account of the
provisions laid down in Directive 82/711//EEC [3], to milligrams of substance released per kilogram of foodstuff.
Repeat this procedure using the second standard solution prepared in 3.2.3.2 to provide a second set
of calibration samples.
3.4.4.3 Olive oil
Weigh 1,0 g ± 0,01 g of 1-octene-free olive oil into a series of five sample vials (3.3.3) and cap
immediately. Add to each vial 200 µl of iso-octane internal standard solution (3.2.3.4) through the
septum using the 250 µl microsyringe (3.3.5). Add through the septum into the vials the same
volumes of standard solution (3.2.3.2) and DMAA (3.2.2) as given in the table under 3.4.3.1 to obtain
the same concentrations as given there. Mix thoroughly.
Prepare each calibration sample at least in duplicate.
Calculate the exact concentrations of the calibration samples in micrograms of 1-octene added per
gram of olive oil, which corresponds to milligrams per kilogram of olive oil food simulant.
Repeat this procedure using the second standard solution prepared in 3.2.3.2 to provide a second set
of calibration samples.
3.5 Procedure
3.5.1 Headspace gas chromatographic analysis (HSGC)
3.5.1.1 General
Examine the baseline stability and response linearity of the detector before starting measurements.
Maintain the same operating conditions throughout the measurement of all samples and calibration
solutions.
Inject each solution at least in duplicate, i.e. fill two headspace vials with the same solution and
analyze each vial once.
NOTE Under the conditions given in 3.3.2 (a), the retention times of 1-octene and iso-octane were 4,2 min
and 6,3 min, respectively. Approximately 20 min are enough to perform a complete analysis programme.
3.5.1.2 Sample treatment
Analyze the test samples, blanks and calibration samples prepared in 3.4.1 to 3.4.3 as they are
without any further sample treatment.
3.5.1.3 Execution of the determination
Equilibrate sample, calibration and blank vials, prepared in accordance with 3.4, in the thermostatted
manifold, kept at 70 °C, of the automated headspace sampler for 80 min before sampling and
commencing the analysis programme (see NOTE to 3.3.2).
Identify the 1-octene and iso-octane peaks on the basis of their retention time and measure the
respective peak heights or read the computer print-out of the peak areas.
Calculate the ratio between the 1-octene peak area and the iso-octane peak area to obtain the peak
area ratio (PAR).
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3.5.2 Calibration
Measure the calibration samples (3.4.3) as described in 3.5.1. Construct or calculate the calibration
curve plotting PAR values against the concentration of 1-octene in milligrams per kilogram of food
simulant.
The calibration curves shall be rectilinear and the correlation coefficient shall be 0,996 or better.
The two sets of calibrant solutions made from independently prepared stock solutions shall be cross-
checked by generating two calibration curves which on the basis of peak area measurement shall
agree to ± 5 % of one another.
Inject each solution at least in duplicate.
3.5.3 Evaluation of data
NOTE The following calculations assume that for all measurements exactly the same volume, i.e. 1,0 ml of
aqueous food simulant or 1,0 g of olive oil, has been used and that in all cases the same volume of internal
standard solution, i.e. 200 µl of internal standard solution, 3.2.3.4 has been added.
Following the method described, no interferences have been observed.
If a 1-octene-free sample shows an interference in the iso-octane region of the chromatogram
exceeding 10 % of the area of iso-octane in the calibration samples (3.4.3), and if the analysis of
replicate blank samples reveals that this interference varies by more than ± 20 % in absolute size,
external calibration shall be used.
If the analysis of the zero point calibration sample (3.4.3) shows a peak in the 1-octene region
corresponding to less than 1,5 mg/kg when calculated in accordance with 3.5.3.1/3.5.3.2 and the
absolute area of duplicates does not vary by more than 10 %, the PAR of the zero point calibration
sample shall be subtracted from the ratios of the test sample and the calibration samples and the data
plotted as in 3.5.2. If the interference corresponds to more than 1,5 mg/kg, the method of standard
addition shall be used.
3.6 Expression of results
3.6.1 Calculation of analyte level
3.6.1.1 Graphical determination
Calculate the average of PAR-values obtained from the test samples in accordance with 3.5.1 and
read the 1-octene concentration of the test sample from the calibration graph (3.5.2).
3.6.1.2 Calculation from the regression parameters
If the regression line equation is:
y[PAR] =()a× x +b
where
y [PAR] is the peak area ratio of 1-octene/iso-octane;
a is the slope of the regression line;
x is the concentration of 1-octene in the food simulant in milligrams per
kilogram;
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b is the intercept of the regression line,
then the concentration of 1-octene in the food stimulant is given by:
y−b
C =
octene,fs
a
where
C is the concentration of 1-octene in the food simulant, in milligrams per kilogram.
octene,fs
Both procedures yield directly the 1-octene concentration in the food simulant in milligrams per
kilogram.
The method applying calculation from the regression parameters is the preferred method.
3.6.2 Calculation of the specific migration of 1-octene
Depending on the fill volume of the test material and on the surface area/food simulant ratio, the
concentration in the laboratory sample as determined in accordance with 3.6.1 may need
mathematical transformation to calculate the specific migration value to be compared with the specific
migration limit (SML). For guidance see EN 13130-1:2004, Clause 13.
3.6.3 Precision
3.6.3.1 Validation
This method was pre-validated by a collaborative trial with two laboratories. In each laboratory within-
laboratory precision experiments were performed using the four official EC food simulants for
establishment of precision data at the restriction criterion as well as migration testing using a linear
low density polyethylene (LLDPE) film sample in contact with 15 % v/v aqueous ethanol and olive oil,
respectively.
3.6.3.2 Repeatability and reproducibility
Evaluation of the within-laboratory precision experiment results according to ISO 5725, at a
concentration of 15 mg/kg yielded the following performance characteristics at the 95 % probability
level (lab 1/lab 2):
Repeatability: r = 0,94/0,31 mg 1-octene per kilogram of water;
r = 0,85/0,28 mg 1-octene per kilogram of 3 % w/v aqueous acetic
acid;
r = 1,90/0,42 mg 1-octene per kilogram of 15 % v/v aqueous ethanol;
r = 3,56/2,49 mg 1-octene per kilogram of olive oil.
3.6.3.3 Detection limit
The within-laboratory detection limit (WDL) of 1-octene, based on the calibration curve method
according to DIN 32645, was found to be in the range of 0,20 mg/kg to 2,0 mg/kg, depending on the
simulant used. Thus the method is capable of quantitative detection at a minimum value of 2,0 mg
1-octene per kilogram.
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3.7 Confirmation
3.7.1 Requirement for confirmation
If the specific migration of 1-octene into the food simulant, calculated according to the procedure given
in EN 13130-1, from the analyte level calculated according to 3.6.2 exceeds a restriction, i.e. a specific
migration limit (SML) of 15 mg/kg, the result of the determination shall be confirmed by
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