The Properties of Iontosorb DEAE
To basic characteristics of this anex the sorption of BSA (bovine serum albumine) belongs. The capacity of BSA sorption is often given at anexes of other producers and therefore it is relatively comparable. Nevertheless, it strongly depends on sorbent porosity.
The BSA volume capacity of Iontosorb DEAE for various porosities is given in the following picture together with volume capacity for chloride anions. As it can be seen from this picture, the BSA capacity increases with increasing anex porosity, but capacity for chlorides with increasing anex porosity decreases. This decrease of volume capacity for small ions is general phenomenon of porous materials and it is caused by the high content of water and low content of dry matter in porous materials.On the contrary, macropores in cellulose skeleton enable large biomolecules to penetrate to functional groups even in the centre of particle and therefore capacity for proteins, enzymes and other biomaterial increases with increasing porosity of a macroporous sorbent.
The determination of volume capacity for BSA was perfomed by Ing. Jirí Kucera, Ph. D. by common method used in Research Institute of Food Industry in Prague.
Water content in Iontosorb DEAE expressed in % increases with increasing porosity of the sorbent. Water content expressed as W.R. (Water Regain, [g H2O/g]) determines the weight of water in grams, which is held by 1 gram of dry matter. If we assume the density of water 1,00 g/ml (at 4 oC), we can assume W.R. to be equal to the volume of pores (ml/g) in swollen sorbent containing 1 g of dry matter. Water content in % and as W.R. is determined by a common method according to CSN 64 0902 (Czech standard).
The capacity of Iontosorb DEAE for chloride anions, expressed as weigth capacity related to 1 g of dry matter, increases with increasing porosity, but if it is expressed as volume capacity related to 1 ml of column filled with swolen sorbent and water, it decreases with increasing porosity, because the content of dry matter in a swollen sorbent decreases with increasing porosity.
