Differentiating Resin Oligomers from MOSH/MOAH...Analysis of saturated and aromatic hydrocarbons...
Transcript of Differentiating Resin Oligomers from MOSH/MOAH...Analysis of saturated and aromatic hydrocarbons...
Representing European based producers of resins
Members of the European Chemical Industry Council (Cefic).
HARRPA exists since 1991
15 member companies in Europe for a total yearly production of more than 1 million tons and a total turnover around 1,5 billion euros
>30 production sites in Europe / employing >3,000 people
Hydrocarbon Resins, Rosin Resins and Pine Chemicals
Producers Association
Differentiating Resin Oligomers from MOSH/MOAH
Annual Conference FEICA, Riga, 12-14 September 2018
Henk-Jan de Jager
Ruud van der Eerden
Michaela Hofbauer
From-Farm-to-ForkFood safety
Content
• Introduction
• What are Resins?
• What are Mineral Oils?
• What is the issue?
• 2D vs 1D GC: C9 and DCPD Resins
• Take-away messages
Plant growthHarvesting &
StorageTransport
Food
processing
& Packaging
Retailer Consumer
Crop protection
Environmental contamination: accidental
Processing: Machine oils
Processing:
Machine oils
Packaging: Migration
• Produced from feedstocks that originate from pine trees
• The main building block used for rosin resins production is rosin (Colophonium)
• Terpene resins are polymerized from terpenes
• Rosin can be chemically modified through disproportionation, hydrogenation,
dimerization and/or fortification with organic acids
• Esterification of rosin with alcohols yields rosin esters
→ Rosin and terpene resins are not mineral oils!
What are … Resins?Rosin and Terpene Resins are low molecular weight, high Tg polymers
Tall Oil RosinGum Rosin
Wood Rosin
Crude oil: “…… cracking operations generate olefins (alkenes and cycloalkenes), …. Olefins are not present in crude petroleum.”
National Research Council. 1985. Oil in the Sea: Inputs, Fates, and Effects. Washington, DC: The National Academies Press, p.25.
• Crude oil fractions (naphtha) are fed to steam-crackers to produce ethylene, propylene as well as other products
• Monomers for hydrocarbon resins (olefins and di-olefins) are also created in the steam cracker process
• Monomers are identified according to their chemical nature (e.g. C5, C9, ...)
• Resins oligomers in hydrocarbon resins are formed as integral part of the resin polymerization process,
Hydrocarbons resins are obtained by polymerizing hydrocarbon monomers such as C5, C9 and DCPD.
C5 C9
What are … Resins?Hydrocarbon resins
Oligomers Mw
DCPD
→ The monomers used to make hydrocarbon resins are not present in crude oil,
but synthetically produced! Hydrocarbon resins are not mineral oils!
Concawe (Mocrinis Workshop, 2017)
Mineral oil is a generic term used to group several petroleum derived liquids, manufactured by
atmospheric and vacuum distillation of crude oil followed by further refinement through extraction,
dewaxing and hydrogenation or other treatment.
What are … Mineral Oils?
According to EFSA opinion (2012):
“hydrocarbons containing 10 to about 50 carbon atoms, where the crude mineral oils remain by far
the predominant source of the mineral oil hydrocarbons considered, but equivalent products can be
synthesised from coal, natural gas or biomass.”
• Significant difference between definitions
• A clear mineral oil definition is missing
Source: Concawe Mocrinis II Workshop (Brussels, 17-18 October 2017); https://www.concawe.eu/wp-content/uploads/2017/10/DEF_C_MM_digital.pdf
Definitions
Mineral oil expressed as MOSH (Mineral Oil Saturated Hydrocarbons) and MOAH (Mineral Oil Aromatic Hydrocarbons)
Identified as a potential source of food contamination, primarily through recycling of paper
Mineral oils sparked controversy about the health hazards of MOSH/MOAH species (bioaccumulation, carcinogenicity)
Consumers groups (e.g. Food Watch) expressed their concerns
Wish to monitor the situation and develop an inventory as a basis for possible regulatory action
Regulations may be pursued that limit the MOSH/MOAH content of packaging materials
Consequences for food producers, food packagers and their suppliers
What is the issue?Contamination of mineral oils in food is a matter of food safety!
Action EC: Recommendation (EU) 2017/84: Monitoring of mineral oil hydrocarbons in food
Generate reliable and comparable results
Determine the possible source of mineral oil
European Reference Laboratory (EU-RL) develops guidance for suitable test method
Guidance stipulates the use of 1D GC analysis
Test method suitable if you accept that all C10-C50 is MOSH/MOAH – even products of biological or vegetable
origin
Listed components in the Union list of the Plastics Regulation might contribute to MOSH/MOAH levels
Demonstrated (*) that 1D GC does not sufficiently distinguish between mineral oils and other low molecular
weight hydrocarbons
If MOSH/MOAH levels are regulated, an improper analytical method could lead to the dismissal of evaluated and
approved food contact materials
(*) Lommatzsch, M., Biedermann, M., Grob, K., & Simat, T. (2016, October 17). Analysis of saturated and aromatic hydrocarbons migrating from
polyolefin-based hot-melt adhesive into food. Food additives & contaminants, Part A, 33(3), 473-488
Implementing EU Recommendation
Challenges due to selectivity of the test methodAnalytical technique: 1D GC
Real world: recycled cardboard
Analytical technique: 1D GC
1. Measures all hydrocarbons: Insufficient selectivity for mineral oil constituents and non-mineral oil
constituents.
2. Broad unresolved hump too complex for ID purposes: Too many peaks (=substances)
Severe overlap of peaks (resolution)
Ideal world: clean GC
What is the issue?
Resin oligomers are not MOSH / MOAH!
Need to develop an improved analytical technique that can distinguish between resin oligomers and MOSH/MOAH
What is the issue?Analytical technique: 2D GC
Feedstock Tall Oil Rosin Rosin Terpene DCPD DCPD/C9 C9 C5 PMR
Modification /
Type
Non-H2 Glycerol Ester
α,β-Pinene mixture
Non-H2 Non-H2 Non-H2 Non-H2AMS /
Styrene
Glycerol Rosin Ester
Partial H2 Glycerol Ester
Terpene Phenol resin
Partial H2 Partial H2 Partial H2Aromatic Non-H2
Penta Rosin Ester
H2 H2 H2
HARRPA
• Initiative to develop a technique to distinguish between MOSH/MOAH and resins (Laboratory Lommatzsch & Säger)
• Create awareness of the difference between MOSH/MOAH and resins among stakeholders.
Resin families selected by HARRPA for 1D GC and 2D GC analyses
1D GC: C9 resins
Resin Saturated Hydrocarbons Resin Aromatic Hydrocarbons
H2
Partial H2
non H2
H2
Partial H2
non H2
C10-C50
Recycled cardboard - Extract
2D vs 1D GC
Overlap of MOSH/MOAH with resin oligomers could result in false positives!
Analytical technique: 2D GC
Recycled cardboard – Extract
Food print of a mineral oil
Main border cyclic MOSHMonoaromatics
Di-aromatics
Tri-aromatics
Poly-aromatics
Internal standards
MOSH
Orientation in 2D GC
Hydrocarbon separation based on:
• 1D GC Volatility
• 2D GC Volatility and Polarity
2D vs 1D GC
A. Dimers
B. Trimers
C. Tetramers
Non H2
partial H2
H2
C
2D GC: C9 resins
Saturated hydrocarbons
Unsaturated hydrocarbons
2D vs 1D GC
Mineral Oil footprint
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2D GC: H2-DCPD resin
A. Trimer
B. Tetramer
C. Pentamer
D. Hexamer
2D vs 1D GC
Saturated hydrocarbons Unsaturated hydrocarbons
• 1D GC is intended to determine (un)saturated hydrocarbons, but is limited for mixtures of hydrocarbons from
different sources.
• Concentrations of hydrocarbons in different fractions can be determined, but a qualitative evaluation is hardly
feasible.
• 2D GC identified and differentiated the vast majority of the resin oligomers from mineral oil hydrocarbons.
This calls for a reliable and adequate (2D GC) analysis
Correct Interpretation is key
Possibility to trace source of contamination
HARRPA strongly recommends that 2D GC is
accepted and endorsed for MOSH/ MOAH
analysis
EU Recommendation 2017/84 stipulates:
• Generate reliable and comparable results of the monitoring
• Determine the possible source of mineral oil
Conclusions
2D vs 1D GC
Take-away messages
1. Resins are not minerals oils!
2. The 1D (JRC method) is supposed to focus on finding MOSH and MOAH – false positives have been identified
3. HARRPA with Lommatzsch lab evaluated 2D GC
• Differentiation between resins and MOSH/MOAH
• HARRPA encourages stakeholders to use 2D GC
4. 2D GC technology is more sophisticated and should be endorsed as a complimentary method
5. Our industry (HARRPA) is committed to continue working with all stakeholders on this to further develop a suitable
method
HARRPA Position paper on Resin and mineral oil analysis in food contact materials: http://www.harrpa.eu/images/Publications/HARRPA_MOSHMOAH_201712.pdf
Acknowledgement to Laboratory Lommatzsch & Säger
Backup Slides
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Source: Concawe Mocrinis II Workshop (Brussels, 17-18 October 2017); https://www.concawe.eu/wp-content/uploads/2017/10/DEF_C_MM_digital.pdf
What are Mineral Oils?
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Concawe definition mineral oil
MOSH: Mineral Oil Saturated Hydrocarbons
- chromatographic measure of alkane content of a mineral oil.
MOAH: Mineral Oil Aromatic Hydrocarbons
- chromatographic measure of aromatic content of a mineral oil.
MOSH and MOAH are not substances, but constituents in mineral oil!
What are MOSH / MOAH?
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Concawe definition MOSH & MOAH
Who are the stakeholders?Overview situation
HPLC-GCxGC-
FID/MS (2D)
HPLC-GC-
FID (1D)
2D GC Mineral Oil
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• This 2D GC chromatogram of
mineral oil mix
• 2D GC chromatogram of the MOAH
fraction of a mineral oil mix
MOAH fraction
• SIC technology allows to show on the chromatogram, species made of selected fragments only
• Fragment 91 m/z (tropylium ion) can be used to visualize most of the monoaromatics or aromatics
containing only single aromatic rings
• Fragment 117 m/z characteristic for monoaromatics with an indane basic structure
• Species showing same fragments and eluting in different locations have different chemical structure
Single Ion Chromatogram differentiation (SIC)
Both examples show main elution areas between the 1- and 2-line as expected
C9 resin
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The C9-oligomers are assembled from different mono-aromatic-units, which can be displayed by
fragments 91 and 117 m/z. Contrary to MOAH, the oligomers from C9 resins do not contain
condensed aromatic ring systems as basic structure
• C9 dimers and trimers, whether partially- (dotted circles) or non-H2 (solid line circles), show main elution areas
below the 2-line.
• Significant overlapping with monoaromatic MOAH cannot be observed.
• C9 Oligomers are distinguished from MOAH species
C9 resin
Single Ion Chromatogram differentiation (SIC)
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• Similar differentiation study is done on C9 modified DCPD resins :
• Aromatic-modified DCPD resin oligomerss (CPD/C9 dimers – hexamers), whether partially- (solid
line circles) or non-H2 (dotted circles), show also main elution areas below the 2-line.
• A significant overlapping with monoaromatic MOAH cannot be observed .
• C9 modified DCPD Oligomers are distinguished from MOAH species
Single Ion Chromatogram differentiation (SIC)
C9 modified DCPD resin
HARRPA – contact details
The mailing address of the organisation is:
Cefic / HARRPA
Avenue E van Nieuwenhuyse 4
B - 1160 Brussels (Belgium)
www.harrpa.eu
For further assistance, please contact:
Joël Wilmot
Tel +32.2.676.72.88
email: [email protected]
Karin Coiffard
Tel : +32 2 676 74 93
E-mail : [email protected]
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