Deciphering the complexity of the chemicals in food packaging materials using molecular networks.

Chemicals from packaging materials might be transferred into food resulting in consumer exposure. Identifying these migrated chemicals is highly challenging and crucial to perform their safety assessment, usually starting by the understanding of the chemical composition of the packaging material itself. This study explores the use of the Molecular Networking (MN) approach to support identification of the extracted chemicals.

Interlaboratory Study to Evaluate a Testing Protocol for the Safety of Food Packaging Coatings.

According to European regulations, migration from food packaging must be safe. However, currently, there is no consensus on how to evaluate its safety, especially for non-intentionally added substances (NIAS). The intensive and laborious approach, involving identification and then quantification of all migrating substances followed by a toxicological evaluation, is not practical or feasible.

Mineral oil hydrocarbons in foods: is the data reliable?

The contamination of foods with mineral oil hydrocarbons (MOH) is a serious concern, requiring in most cases tedious mitigation measures that span across the whole food supply chain. A major issue today is the significant variability of the results generated by laboratories. This study was therefore designed to achieve a deeper insight into the analytical procedures used by commercial laboratories, identifying possible gaps and suggesting improvements that will enhance the reliability of the MOH data, an important prerequisite for risk assessment.

Synthesis, identification and quantification of oligomers from polyester coatings for metal packaging.

Polyester can coatings protect both food and packaging from mutual contamination. Even though, can coatings may release Non-Intentionally Added Substances (NIAS) in addition to Intentionally Added Substances (IAS). As NIAS are mainly constituted by cyclic or linear side products that are formed during the polymerization process, we focused our attention on these oligomeric species of molecular weight <1000 Da.

Integrating bioassays and analytical chemistry as an improved approach to support safety assessment of food contact materials.

Food contact materials (FCM) contain chemicals which can migrate into food and result in human exposure. Although it is mandatory to ensure that migration does not endanger human health, there is still no consensus on how to pragmatically assess the safety of FCM since traditional approaches would require extensive toxicological and analytical testing which are expensive and time consuming. Recently, the combination of bioassays, analytical chemistry and risk assessment has been promoted as a new paradigm to identify toxicologically relevant molecules and address safety issues.

A novel safety assessment strategy applied to non-selective extracts.

A main challenge in food safety research is to demonstrate that processing of foodstuffs does not lead to the formation of substances for which the safety upon consumption might be questioned. This is especially so since food is a complex matrix in which the analytical detection of substances, and consequent risk assessment thereof, is difficult to determine. Here, a pragmatic novel safety assessment strategy is applied to the production of non-selective extracts (NSEs), used for different purposes in food such as for colouring purposes, which are complex food mixtures prepared from reference juices.

A novel safety assessment strategy for non-intentionally added substances (NIAS) in carton food contact materials.

One of the main challenges in food contact materials research is to prove that the presence of non-intentionally added substances (NIAS) is not a safety issue. Migration extracts may contain many unknown substances present at low concentrations. It is difficult and time-consuming to identify all these potential NIAS and concurrently to assess their health risk upon exposure, whereas the health relevance at low exposure levels might not even be an issue.

Application of the TTC concept to unknown substances found in analysis of foods.

Unknown substances, not previously observed, are frequently detected in foods by quality control laboratories. In many cases, the assessment of these 'new' substances requires additional chemical analysis for their identification prior to assessing risk. This identification procedure can be time-consuming, expensive and in some instances difficult.

Application of the threshold of toxicological concern (TTC) concept to the safety assessment of chemically complex food matrices.

The toxicological assessment of chemically complex food matrices (CCFM) usually is very time consuming, expensive and uses many animal studies. Improvements to obtain a more efficient assessment process remain limited as long as we retain traditional approaches to toxicological risk assessment. New concepts would be needed to achieve real innovations in risk assessment.

An enzymatic microreactor based on chaotic micromixing for enhanced amperometric detection in a continuous glucose monitoring application.

The development of continuous glucose monitoring systems is a major trend in diabetes-related research. Small, easy-to-wear systems which are robust enough to function over many days without maintenance are the goal. We present a new sensing system for continuous glucose monitoring based on a microreactor incorporating chaotic mixing channels.

A decade of microfluidic analysis coupled with electrospray mass spectrometry: an overview.

This review presents a thorough overview covering the period 1997-2006 of microfluidic chips coupled to mass spectrometry through an electrospray interface. The different types of fabrication processes and materials used to fabricate these chips throughout this period are discussed. Three 'eras' of interfaces are clearly distinguished.

Microfluidics/CMOS orthogonal capabilities for cell biology.

The study of individual cells and cellular networks can greatly benefit from the capabilities of microfabricated devices for the stimulation and the recording of electrical cellular events. In this contribution, we describe the development of a device, which combines capabilities for both electrical and pharmacological cell stimulation, and the subsequent recording of electrical cellular activity. The device combines the unique advantages of integrated circuitry (CMOS technology) for signal processing and microfluidics for drug delivery.

Characterization of a microfluidic dispensing system for localised stimulation of cellular networks.

We present a 3-D microfluidic device designed for localized drug delivery to cellular networks. The device features a flow cell comprising a main channel for nutrient delivery as well as multiple channels for drug delivery. This device is one key component of a larger, fully integrated system now under development, based upon a microelectrode array (MEA) with on-chip CMOS circuitry for recording and stimulation of electrogenic cells (e.

A high current density DC magnetohydrodynamic (MHD) micropump.

This paper describes the working principle of a DC magnetohydrodynamic (MHD) micropump that can be operated at high DC current densities (J) in 75-microm-deep microfluidic channels without introducing gas bubbles into the pumping channel. The main design feature for current generation is a micromachined frit-like structure that connects the pumping channel to side reservoirs, where platinum electrodes are located. Current densities up to 4000 A m(-2) could be obtained without noticeable Joule heating in the system.

The quenching of electrochemiluminescence upon oligonucleotide hybridization.

Many genomic assays rely on a distance-dependent interaction between luminescent labels, such as luminescence quenching or resonance energy transfer. We studied the interaction between electrochemically excited Ru(bpy)(3) (2+) and Cy5 in a hybridization assay on a chip. The 3' end of an oligonucleotide was labelled with Ru(bpy)(3) (2+) and the 5' end of a complementary strand with Cy5.

Using matrix peaks to map topography: increased mass resolution and enhanced sensitivity in chemical imaging.

It is well known in secondary ion mass spectrometry (SIMS) that sample topography leads to decreased mass resolution. Specifically, the ion's time of flight is dependent on where it was generated. Here, using matrix-enhanced SIMS, it is demonstrated that, in addition to increasing the yield of intact pseudomolecular ions, the matrix allows the user to semiquantitatively record the topography of a sample.

Electrokinetic characterization of poly(dimethylsiloxane) microchannels.

This paper characterizes the basic electrokinetic phenomena occurring within native poly(dimethylsiloxane) (PDMS) microchannels. Using simple buffers and current measurements, current density and electroosmosis data were determined in trapezoidal, reversibly sealed PDMS/PDMS and hybrid PDMS/glass channels with a cross-sectional area of 1035.5 microm(2) and about 6 cm length.

Electron capture and collisionally activated dissociation mass spectrometry of doubly charged hyperbranched polyesteramides.

Electron capture dissociation (ECD) of doubly protonated hyperbranched polyesteramide oligomers (1100-1900 Da) was examined and compared with the structural information obtained by low energy collisionally activated dissociation (CAD). Both the ester and amide bonds of the protonated species were cleaved easily upon ECD with the formation of odd electron (OE(.+)) or even electron (EE(+)) fragment ions.

Isomer separation of hyperbranched polyesteramides with gas-phase H/D exchange and a novel MS(n) approach: DoDIP.

Two approaches are introduced that provide information about the isomeric composition of hyperbranched polyesteramides. The first approach is based on a novel tandem mass spectrometric (MS(n)) approach that allows the study of different types of isomeric structures by a separation based on their difference in appearance energy. The method is called DoDIP: dissociation of depleted ion populations.