Interplay between microdynamics and macrorheology in vesicle suspensions.

The microscopic dynamics of objects suspended in a fluid determines the macroscopic rheology of a suspension. For example, as shown by Danker and Misbah [Phys. Rev.

Derivatization and mass spectrometric behaviour of catecholamines and their 3-O-methylated metabolites.

A method has been developed for the derivatization of both catecholamines (dopamine, noradrenaline and adrenaline) and their 3-O-methylated metabolites (3-methoxytyramine, normetanephrine and metanephrine) in a single run. The compounds were first incubated with methanolic hydrochloric acid to methylate those compounds that contain a benzylic hydroxyl group and were subsequently converted into their pentafluoropropionyl derivatives. The derivatives thus prepared, showed good gas chromatographic and electron-impact mass spectrometric properties and can be analysed in a single gas chromatographic run.

Determination of eight volatile nitrosamines in thirty cured meat products with capillary gas chromatography-high-resolution mass spectrometry: the presence of nitrosodiethylamine and the absence of nitrosopyrrolidine.

Five samples each of six cured meat products were analysed for the presence of eight volatile nitrosamines. A combined steam distillation-extraction step at pH 8-9 plus a concentration step were used for preparation of extracts. These were analysed, without further clean-up, using a coupled capillary GC-HRMS system at a resolution of 4 000.