Precipitation biomacromolecule

Fig. 3.5 Representation of a scheme of an experiment (upper set of drawings) and the obtained experimental results presented as AFM images (middle part) and cross-sectional profiles (bottom) that provides evidence of silica nucleation and shell formation on biopolymer macromolecules. Scheme of experiment. This includes the following main steps. 1. Protection of the mica surface against silica precipitation. It was covered with a fatty (ara-chidic) acid monolayer transferred from a water substrate with the Langmuir-Blodgett technique. This made the mica surface hydrophobic because of the orientation of the acid molecules with their hydrocarbon chains pointing outwards. 2. Adsorption of carbohydrate macromolecules. Hydrophobically modified cationic hydroxyethylcellulose was adsorbed from an aqueous solution. Hydrocarbon chains of polysaccharide served as anchors to fix the biomacromolecules firmly onto the acid monolayer. 3. Surface treatment by silica precursor. The mica covered with an acid mono-...

In a broader sense, the removal of interfering molecular species is not unique to GC analyses it has been widely practiced with many other biochemical and clinical determinations. For example, biomacromolecules can be denatured and precipitated through a variety of methods, or alternatively removed by gel-permeation chromatography prior to the sample analysis by GC. Additional purification methods may employ the acidobasic properties of either the interfering molecules, or a sample itself (pH manipulations, ion-exchange chromatography, ion-pairing extraction, etc.). Polar and nonpolar molecules can often be separated from each other in an easy manner as based on their different solubilities. 

Zamani, A., Edebo, L., Sjostrom, B., and M. J. Taherzadeh. 2007. Extraction and precipitation of chitosan from cell wall of Zygomycetes fungi hy dilute sulfuric acid. Biomacromolecules 8 3786-3790. 

Yu, L., Zhang, Z., Zhang, H., Ding, J., 2010. Biodegradability and biocompatibility of ther-moreversible hydrogels formed from mixing a sol and a precipitate of block copolymers in water. Biomacromolecules 11 (8), 2169—2178. 

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