Migration studies

Ivanovich M (1991) Aspects of uranium-tliorium series disequilibrium applications to radionuclide migration studies. Radiochim Acta 52/53 257-268... 

Migration studies (compliance with regulations, blooming, staining medical)... 

A field experiment in a migration study of technetium in the form of TcOj was carried out by Landstrom et al. [64] who injected Tc and radioactive 82Br (non-sorbing tracer) in a highly permeable zone at a borehole. After 10 hours, breakthrough of the tracer was measured, but no retardation, i.e. no reduction of Tc, was observed in comparison with 82Br. 

Fig. 8. Radionuclide migration studied in a granitic shear zone at the Grimsel test site, Switzerland (injection flow rate 10 mL/min extraction flow rate 150 mL/min, dipole distance 2.3 m). Am(III), Pu(IV) and Th(IV) are co-eluted with the colloids grey vertical lines indicate maxima of breakthrough curves (Geckeis et al. 2003). In order to allow a direct comparison of breakthrough curves, the colloid and radionuclide concentrations (c in mg/mL) in the extracted water samples are normalized to the total injected mass of individual colloid or radionuclide tracers (mn in mg).

Hydrolysis reactions are common to all actinide ions in nearneutral solutions, and take place either in parallel with or predominantly over other complexation reactions. In connection with the migration studies of actinide ions in natural waters, attention recently has been focused on hydrolysis reactions of actinides since these reactions are important in determining the solubility of the actinide hydroxide or oxide. Although numerous studies have been made (1-4) to determine stability constants of various hydrolysis products, much of the necessary data are still lacking. The acquisition of these data and further improvement or verification of the existing data is desirable. 

E. Room temperature filled and stored (no thermal treatment in the container). Conduct migration studies for 240 hours at 40 °C (104 °F). Analyze the test solutions after 24, 48,120 and 240 hours. 

Most of the detailed systematic migration studies performed before 1990 were at low temperatures, i.e., less than 60 °C. In 1990, migration of antioxidants from polyolefins (the most common food packaging material) to the food simulants com oil, 95 % ethanol, water, 8 % ethanol and food was studied at high temperatures in the range... 

Figge, K., Koch, J., Freytag, W 1978, The suitability of simulants for foodstuffs, cosmetics and pharmaceutical products in migration studies. Food Cosmet. Tox. 16 (2) 135-142. 

Migration studies aud their relatiouship to dietary iutake 1... 

FS2219 Migration studies - food contact materials. 

The majority of migration studies on food packaging adhesives have been done on materials laminated using reactive adhesive systems. Most of these have focused on polyurethanes. 

This chapter describes the types of materials and articles that may come into contact with snack and take-away foods, the factors affecting chemical migration into these foods and beverages, and provides examples (not exhaustive) of migration studies carried out. The current legislation applicable to these materials is referred to but is described more fully in other chapters. Sources of additional information are provided. 

Specific migration studies in which snack food packaging materiais have been investigated... 

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