Official Food Control Authority of the Canton of Zurich

Zürich, Switzerland

Official Food Control Authority of the Canton of Zurich

Zürich, Switzerland

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Biedermann S.,Official Food Control Authority of the Canton of Zurich | Tschudin P.,Swiss Public Radio DRS | Grob K.,Official Food Control Authority of the Canton of Zurich
Analytical and Bioanalytical Chemistry | Year: 2010

Of 13 thermal printing papers analyzed, 11 contained 8-17 g/kg bisphenol A (BPA). When taking hold of a receipt consisting of thermal printing paper for 5 s, roughly 1 μg BPA (0.2-6 μg) was transferred to the forefinger and the middle finger if the skin was rather dry and about ten times more if these fingers were wet or very greasy. This amount transferred to dry skin was neither significantly increased when taking hold of the paper at up to 10 sites, nor reduced when BPA-free paper was contacted afterwards. After 60-90 min, BPA applied to the skin as a solution in ethanol was only partially or no longer at all extractable with ethanol, whereas BPA transferred to the skin by holding thermal printer paper remained largely extractable after 2 h. This suggests that penetration of the skin depends on the conditions. Extractability experiments did not enable us to conclude whether BPA passes through the skin, but indicated that it can enter the skin to such a depth that it can no longer be washed off. If this BPA ends up in the human metabolism, exposure of a person repeatedly touching thermal printer paper for 10 h/day, such as at a cash register, could reach 71 μg/day, which is 42 times less than the present tolerable daily intake (TDI). However, if more than just the finger pads contact the BPA-containing paper or a hand cream enhances permeability of the skin, this margin might be smaller. © 2010 Springer-Verlag.


Zurfluh M.,Official Food Control Authority of the Canton of Zurich | Biedermann M.,Official Food Control Authority of the Canton of Zurich | Grob K.,Official Food Control Authority of the Canton of Zurich
Food Additives and Contaminants - Part A Chemistry, Analysis, Control, Exposure and Risk Assessment | Year: 2013

Conventional migration testing for long-term storage at ambient temperature with Tenax® was applied to a recycled paperboard as well as to the same paperboard with a polyethylene or polypropylene film in between. Test conditions were from the European Union plastic Regulation 10/2011, that is, 10 days at 60°C, but previous standard conditions of 10 days at 40°C were also applied. The results were compared with the migration into real packs made of the same packaging material containing six test foods and stored over 9 months. For the direct contact, simulation at 60°C overestimated the maximum migration of the saturated hydrocarbons in the real packs by 73%. Simulation reflected hardly any effect by the plastic films and resulted in an overestimation of the maximum migration into the real packs by a factor of 5.1 and 27 for the polyethylene and the polypropylene film, respectively. Analogous simulation was performed with polenta (corn semolina) instead of Tenax®. Three main causes for this deviation were identified: (i) at 60°C, migration reached beyond n-C35, whereas it ends at about n-C24 in reality. (ii) Tenax® is a far stronger adsorbent than foods, resulting in almost complete extraction. (iii) The significant barrier effect of polypropylene films at ambient temperature is lost at increased temperature. The suitability of such simulation for the prediction of long-term migration is questioned. © 2013 Copyright Taylor & Francis.


Biedermann M.,Official Food Control Authority of the Canton of Zurich | Grob K.,Official Food Control Authority of the Canton of Zurich
European Food Research and Technology | Year: 2010

Recycled paper and board used in food packaging materials (boxes, paper bags) often cause migration of mineral oil into food at levels which are unacceptable according to present toxicological assessments. When foods in recycled board are densely packed into larger boxes or onto pallets, most of the hydrocarbons up to n-C 20 may migrate into the packed food within a few weeks, those up to n-C 28 at a decreasing rate. Unprinted recycled board contained 300-1,000 mg/kg mineral oil


Biedermann M.,Official Food Control Authority of the Canton of Zurich | Grob K.,Official Food Control Authority of the Canton of Zurich
Journal of Chromatography A | Year: 2013

Safety for food application means absence of toxic compound.Safety would presuppose comprehensive analysis of potential migrants.With the method applied, more than 250 potential migrants were detected.For roughly 2/3 of the substances a tentative identification was possible.Recycled paperboard contains too many substances for this approach to be realistic. A method for determining potentially health-relevant components in paperboard used for packaging dry foods as comprehensively as technically feasible was applied to a sample of recycled paperboard. The task was specified by a detection limit in food of 0.01. mg/kg, from which a detection limit of 0.1. mg/kg in paperboard was derived. Extracts from the paperboard were preseparated into seven fractions by high performance liquid chromatography (HPLC) and transferred on-line to gas chromatography with flame ionization detection (GC-FID). The chromatograms visualize the high complexity of the material that may migrate into foods at toxicologically potentially relevant concentrations. Since only a minority of the substances was also detectable in fresh fiber board, most must have originated from chemicals used in the paper and board fed into the recycling process. Significant variability between recycled paperboards of four manufacturers was observed because of varying feedstocks. Using comprehensive two-dimensional GC (GC. ×. GC) with time of flight mass spectrometry (TOF-MS), more than 250 substances were counted that probably exceeded the detection limit and were probably of sufficient volatility for migration into dry food. It is concluded in three main messages to risk managers: (i) since most potential migrants have not been adequately evaluated, many not even identified, the safety required by Article 3 of EU Regulation 1935/2004 has not been ensured; (ii) the number of substances potentially migrating into food above 0.01. mg/kg is too large to realistically be brought under control; (iii) a barrier reducing the migration into food by a factor of 100 over the life time of a product would keep the migration of all except a few well known substances below 0.01. mg/kg in food. © 2013 Elsevier B.V..


Grob K.,Official Food Control Authority of the Canton of Zurich
Food Control | Year: 2014

EU legislation requires that the materials migrating from packaging and other food contact materials (FCM) into food do not endanger human health, which means the absence of a substance transferred to food in potentially health-relevant amounts. Hardly any FCM has been investigated to the extent complying with this requirement. At best the starting substances were evaluated. However, usually the larger part of the migrates consists of oligomers, reaction products and impurities (ORPIs), of which often not even the composition is known. This is not new, but the legally required compliance declarations render it more evident: even though most FCM do not fully comply with the legal requirement, the declarations have to state this, as FCM cannot be marketed otherwise - which is an awkward situation. A system is proposed rendering the gaps in the compliance work temporarily tolerable, provided these are described and registered with the business operators behind them. The owners of the gap description elaborate work plans, which have to be discussed and approved by competent authorities. These plans have to be realistic in terms of feasibility and timelines. Such gap descriptions can be listed in compliance declarations for an honest statement on compliance. The system introduces flexibility and is promising to get the present situation out of the deadlock. © 2014 Elsevier Ltd.


Biedermann M.,Official Food Control Authority of the Canton of Zurich | Grob K.,Official Food Control Authority of the Canton of Zurich
Journal of Chromatography A | Year: 2013

Insertion of a programmed temperature vaporizing (PTV) injector under conditions of concurrent solvent recondensation (CSR) into the on-line HPLC-GC interface for on-column transfer (such as the retention gap technique with partially concurrent eluent evaporation) enables filtering off high boiling or involatile sample constituents by a desorption temperature adjusted to the required cut-off. Details of this technique were investigated and optimized. Memory effects, observed when transferred liquid was sucked backwards between the transfer line and the wall of the injector liner, can be kept low by a small purge flow rate through the transfer line at the end of the transfer and the release of the liquid through a narrow bore capillary kept away from the liner wall. The column entrance should be within the well heated zone of the injector to prevent losses of solute material retained on the liner wall during the splitless period. The desorption temperature must be maintained until an elevated oven temperature is reached to prevent peak broadening resulting of a cool inlet section in the bottom part of the injector. © 2013 Elsevier B.V.


Biedermann M.,Official Food Control Authority of the Canton of Zurich | Grob K.,Official Food Control Authority of the Canton of Zurich
Journal of Chromatography A | Year: 2013

Legislation on food contact materials, mainly focusing on food safety, requires the absence of potentially harmful substances in the migrate from packaging materials. For recycled paperboard with essentially unknown input this presupposes comprehensive analysis of all substances potentially migrating above the regulatory threshold. Present chemical analysis is strong in target analysis, but not in methodologies enabling comprehensive analysis of unknown mixtures at low detection limits. An attempt was made to analyze the potential migrants into dry foods as comprehensively as possible. The required detection limit was derived from the conventional regulatory European detection limit of 0.01. mg/kg in food, which was approximated by a detection limit in paperboard of 0.1. mg/kg. Various obstacles had to be overcome and adjusted or even new tools were required. Compromises were unavoidable, which could have resulted in loss of relevant components. This paper points out facets of related analytical methodology, but also provides an analytical base for the information of regulators about the feasibility of the old legal requirements that substances endangering human health must not migrate into food. © 2012 Elsevier B.V.


Biedermann M.,Official Food Control Authority of the Canton of Zurich | Grob K.,Official Food Control Authority of the Canton of Zurich
Journal of Chromatography A | Year: 2015

Many foods are contaminated by hydrocarbons of mineral oil or synthetic origin. High performance liquid chromatography on-line coupled with gas chromatography and flame ionization detection (HPLC-GC-FID) is a powerful tool for the quantitative determination, but it would often be desirable to obtain more information about the type of hydrocarbons in order to identify the source of the contamination and specify pertinent legislation. Comprehensive two-dimensional gas chromatography (GC. ×. GC) is shown to produce plots distinguishing mineral oil saturated hydrocarbons (MOSH) from polymer oligomeric saturated hydrocarbons (POSH) and characterizing the degree of raffination of a mineral oil. The first dimension separation occurred on a phenyl methyl polysiloxane, the second on a dimethyl polysiloxane. Mass spectrometry (MS) was used for identification, FID for quantitative determination. This shows the substantial advances in chromatography to characterize complex hydrocarbon mixtures even as contaminants in food. © 2014 Elsevier B.V.


Biedermann M.,Official Food Control Authority of the Canton of Zurich | Grob K.,Official Food Control Authority of the Canton of Zurich
Journal of Chromatography A | Year: 2012

Mineral oil hydrocarbons are complex as well as varying mixtures and produce correspondingly complex chromatograms (on-line HPLC-GC-FID as described in Part 1): mostly humps of unresolved components are obtained, sometimes with sharp peaks on top. Chromatograms may also contain peaks of hydrocarbons from other sources which need to be subtracted from the mineral oil components. The review focuses on the interpretation and integration of chromatograms related to food contamination by mineral oil from paperboard boxes (off-set printing inks and recycled fibers), if possible distinguishing between various sources of mineral oil. Typical chromatograms are shown for relevant components and interferences as well as food samples encountered on the market. Details are pointed out which may provide relevant information. Integration is shown for examples of paperboard packaging materials as well as various foods. Finally the uncertainty of the analysis and limit of quantitation are discussed for specific examples. They primarily result from the interpretation of the chromatogram, manually placing the baseline and cuts for taking off extraneous components. Without previous enrichment, the limit of quantitation is between around 0.1. mg/kg for foods with a low fat content and 2.5. mg/kg for fats and oils. The measurement uncertainty can be kept clearly below 20% for most samples. © 2012 Elsevier B.V.


Biedermann M.,Official Food Control Authority of the Canton of Zurich | Grob K.,Official Food Control Authority of the Canton of Zurich
Journal of Chromatography A | Year: 2012

For the analysis of mineral oil saturated hydrocarbons (MOSH) and mineral oil aromatic hydrocarbons (MOAH), on-line coupled high performance liquid chromatography-gas chromatography-flame ionization detection (HPLC-GC-FID) offers important advantages: it separates MOSH and MOAH in robust manner, enables direct injection of large aliquots of raw extracts (resulting in a low detection limit), avoids contamination of the sample during preparation and is fully automated. This review starts with an overview of the technology, particularly the fundamentals of introducing large volumes of solvent into GC, and their implementation into various transfer techniques. The main part deals with the concepts of MOSH and MOAH analysis, with a thorough discussion of the choices made. It is followed by a description of the method. Finally auxiliary tools are summarized to remove interfering components, enrich the sample in case of a high fat content and obtain additional information about the MOSH and MOAH composition. © 2012 Elsevier B.V.

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