The analysis of migrates from the internal coatings of food cans showed that the present regulation is not sufficient to ensure safety of food contact polymers. The migrates often consist of complex mixtures of reaction products and impurities, and their harmlessness cannot be deduced from the use of non-toxic starting substances compiled in positive lists. The regulation proposed herein asks producers to analyse the composition of the migrates. It includes an upper limit for the molecular weight (e.g. 1000 Da) and thresholds defining concentrations in the foods down to which components must be identified and evaluated. Primarily considering feasibility at reasonable costs, thresholds of 30 micrograms/kg for individual components and 300 micrograms/kg for the sum of the unidentified materials are proposed. Producers must be able to demonstrate that the individual components or mixtures exceeding this limit, including reaction products with food components, have no toxic effect.

Introduction of Magnesium into Ligands of the Chlorophyll Series by (2,6‐Di‐t‐butyl‐4‐methylphenoxy)magnesium Iodide Experimental details are given for the new method of introducing magnesium into porphinoid ligands by (2,6‐di‐t‐butyl‐4‐methylphenoxy)magnesium iodide (1), previously published in preliminary form [1]. Besides magnesium octaethylporphyrinate (14), methyl pyrochlorophyllide a (10), methyl chlorophyllide a (8), and methyl bacteriochlorophyllide a (12), the complexation of pheophytin a (2) to chlorophyll a (3) and of pheophytin b (4) to chlorophyll b (5) are described.

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Nach einer neuen Methode wurden durch Reaktion von Phäophytin a bzw. b mit der Titel‐Grignardverbindung Chlorophyll a (Ia) bzw. b (Ib) dargestellt.

Synthesemöglichkeiten für das Antibioticum‐Aglykon Chlorothricolid (I) werden diskutiert.