Nano-sized ion exchangers possess high ion exchange capacity, adhesion to quartz surface and pH-independent charge, which make them promising stationary phases for the high-efficient and selective separation of charged analytes in the capillary electrochromatography mode. The goal of the investigation was the application of nano-sized ion exchangers as stationary phases in the capillary electrochromatography. The development of coatings based on nano-sized anion and cation exchanger (polystyrene-divinylbenzene copolymer matrix functionalized with quaternary ammonium and sulfo groups respectively) was proposed for the first time. The proposed procedures of coatings formation were very fast (less than 15 min) and were reproducible. The characterization of coatings was also carried out by the scanning electron microscopy. The high stability of the nano-sized anion exchange coating allowed using background electrolytes with pH range from 2 to 10 for the electrophoretic separations. The lower stability of coatings based on nano-sized cation exchange particles of fused silica capillaries reduced the pH range of possible background electrolytes (pH 2 - 8). Modified by nano-sized anion exchangers capillaries were applied for the separation of inorganic anions and organic acids. The determination of these analytes was characterized by high efficiency, resolution (compared to the results obtained without nano-sized anion exchanger) and short analysis time due to the co-directional migration of analytes and reversed electroosmotic flow. The modification of the fused silica capillary by nano-sized cation exchange particles prevented the sorption of biogenic amines during their electrophoretic separation.
Scopus subject areas
- Analytical Chemistry