Migration Indirect assessment

The amorphous orientation is considered a very important parameter of the microstructure of the fiber. It has a quantitative and qualitative effect on the fiber de-formability when mechanical forces are involved. It significantly influences the fatigue strength and sorptive properties (water, dyes), as well as transport phenomena inside the fiber (migration of electric charge carriers, diffusion of liquid). The importance of the amorphous phase makes its quantification essential. Indirect and direct methods currently are used for the quantitative assessment of the amorphous phase. 

Indirect migration assessment by compositional analysis of plastics Assessment by worst-case assumptions of total mass transfer... 

In all cases under the premise of total mass transfer where an indirect migration assessment demonstrates the impossibility of exceeding a given legal SML restriction criterion, full compliance testing has been achieved and no further migration assessment or testing is necessary. 

An additional indirect assay of neutrophil motility is the actin polymerization assay. Chemoattractants induce a rapid, transient actin polymerization response in neutrophils (reviewed in [289, 391]), and since actin polymerization is required for migration to occur, it is often used as an indication of chemotactic capability. Several approaches have been developed to measure this response (reviewed in [289, 391]) (Table 2). Most commonly, cells in suspension are mixed with a putative chemoattractant then fixed and stained with a fluorescent phaUotoxin that binds to polymerized actin, but not monomeric actin. The bound fluorescence is quantified using flow cytometry or spectrofluorometry. The actin polymerization response to many neutrophil chemoattractants is rapid, reaching a maximum within 10 s of stimulus addition at 37° C. As with the cell polarization assay, no information about the migratory properties of the cells is obtained with the actin polymerization assay, only the likelihood of chemotactic activity is assessed. Like the cell polarization assay, the actin polymerization assay is useful for initial screening of chemoattractants, but must be followed up with an actual measurement of motility. 

The use of nanotechnologies in the food industry may present potential risks to both human health and the environment due to the use of novel materials in novel ways, and risk assessments must be carried out. Three different ways of entrance penetration of nanoparticles in the organism are possible inhalation, skin penetration and ingestion. Free nanoparticles can cross cellular barriers and that exposure may lead to oxidative damage and inflammatory reactions. In the case of nanomaterials for food packaging, many people fear risk of indirect exposure due to potential migration of nanoparticles from packaging materials, in particular nanobiocomposites. 

The FDA prescribes the manner in which data quality is to be assured in its Recommendations for Chemistry Data for Indirect Food Additive Petitions document [42]. This quality assurance requirement is implemented in two ways analyses of replicate samples, and analyses of fortified samples. The replicate analyses serve primarily to assess the inter-sample variability in migration, rather than as an indication of precision of analysis. The analyses of fortified samples assures the accuracy of the measurement system. These analyses are usually conducted on composited extracts of control material. 

Assessment of whether the level of NP migrating from FCMs should be of concern has not reached a consensus in regulatory agencies, partly because NP is predominantly present as an impurity or degradation product as a NIAS. The U.S. Food and Drug Administration (FDA) includes nonylphenol, nonylphenol,p—, octylphenol, octylphenol,p—, and tris(nonylphenyl)phosphite (see Table 5.1) in their List of Indirect Additives Used in Food Contact Substances (FDA 2014), but NP and OP are not approved by the FDA for use as direct food additives. Neither NP nor OP are listed in FDA s Cumulative Estimated Daily Intake database for food contact substances (FDA 2013). 

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