P. H. Thiesen

Process development in affinity separation of glycoconjugates with lectins as ligands

Process development for affinity separation is a crucial prerequisite for a successful biospecific isolation of biological active substances like glycoconjugates or enzymes. The functionalization of polymer and silica based adsorbents and their influence on the adsorption behaviour of the modified adsorbents are presented. Improvement of the immobilization conditions for different lectins lead to a stable binding of more than 90% within 4 h of ligands applied to the immobilization solution. The prepared adsorbents are characterized according to specificity, stability and capacity. The isolation of the glycoprotein fetuin from fetal calf serum with wheat germ agglutinin adsorbents and the purification of horseradish peroxidase with concanavalin A (Con A) adsorbent are described. The Langmuir model, using glucose oxidase as glycoprotein and Con A adsorbents, expresses the sorption behaviour. The fixed bed separation is represented by the dispersion model. The process simulation supports the process development evaluating design parameters and investigating and optimizing process conditions. The influence of the flow as well as the concentration of contaminants competing with the valuable product for the ligands on the separation performance are demonstrated and discussed.

Selective Adsorbents for Improved Removal of Malodorous Compounds

This work presents different methods of adsorbents characterisation. Their use towards improved removal of malodorous compounds is considered. These methods are applied to different modified silica gels. At first, the synthesis conditions were optimised using aminopropylsilanes. Afterwards the stability of the samples against ethanol and water was examined. The modified silica gels are suggested to be selective adsorbents in the field of odour control.

Characterization of adsorbents for odour reduction

The application of adsorbents in odour control can be traced back for centuries, but with low efficiency. Owing to the variety of odours and the sensitivity of the population, powerful techniques for odour control have to be developed. Specific sorption processes are promising. Surface modification of silica gel is a possible way to increase the specificity of the adsorbents. A simple method is introduced to characterize the adsorption behaviour of these materials.