Separation of catecholamines with capillary electrophoresis by using dynamic and static coatings

The studies have been focused on to improve the separation of catecholamines with capillary electrophoresis by using dynamic and static coatings. The results are used in the analyses of drugs from biological fluids with m-chips. Adrenaline, dopamine and noradrenaline are neurotransmitters in the central and peripherial nervous systems. Their determination, together with the compounds formed in their chemical reactions occurring within living organisms, is useful for clinical diagnosis of pheochromocytoma, neuroblastoma and Parkinson s disease. Different analytical methods like HRGC, HPLC and CE have been used for their analyses in urine and blood samples. Capillary electrophoresis (CE) with UV-detection has shown its potential in the determination of catecholamines from urine. When fused silica capillary is used, in-run modification can be formed by positively charged organic molecules, which can adsorb on the negatively charged silanol groups. Therefore covalent bondings are not formed. The reagents, which adsorb on the silica wall, are used as additives in the electrolyte solution, and thus they can be actively changed with fresh molecules. The commonly used modifiers for in-run modification have been e.g. ethyleneamine, different salts acting as zwitterions or triethylamine.