title: Long-term analyses in automated electrophoretic analyzer in hydrodynamically closed separation system.
abstract: Some potential problems that can occur during the analyses of complex samples by on-line combination of capillary isotachophoresis-capillary zone electrophoresis (cITP-CZE) in automated electrophoretic analyzer with the column-coupling configuration of the separation unit were studied in this work. The main focus was devoted on the reproducibility of important analytes' parameters (migration time, peak height and peak area) and also on the stability studies of selected low and high molecular mass analytes of inorganic/organic origins (bromate, vitamins, proteins) present at low concentration levels in different kinds of matrices (mineral water, human urine). Such study was carried out for the first time for the electrophoretic analyzer operating in the hydrodynamically closed separation system provided with contact-less conductivity detectors and UV detector in CZE step. Hydrodynamic and electroosmotic flows of the buffer solutions were suppressed and therefore, only the electrophoretic transport of ions was significant. Obtained results showed the different stabilities of the analytes and samples depending on their origin. The focus in the long-term analyses should be paid on the storage of the samples and on the regular changing the contents of electrolyte vessels to keep the electrolyte composition and separation conditions as constant as possible.
authors.affiliation: Department of Analytical Chemistry, Faculty of Natural Science, Comenius University in Bratislava, Mlynská Dolina CH-2, 84215 Bratislava, Slovak Republic. Electronic address: stanova@fns.uniba.sk.
authors.forename: Andrea Vojs
authors.initials: AV
authors.lastname: Staňová
authors.affiliation: Department of Analytical Chemistry, Faculty of Natural Science, Comenius University in Bratislava, Mlynská Dolina CH-2, 84215 Bratislava, Slovak Republic.
authors.forename: Martina
authors.initials: M
authors.lastname: Hrenáková
authors.affiliation: Department of Analytical Chemistry, Faculty of Natural Science, Comenius University in Bratislava, Mlynská Dolina CH-2, 84215 Bratislava, Slovak Republic.
authors.forename: Jozef
authors.initials: J
authors.lastname: Marák
mesh_terms: D001959:Bromates / Q000032:analysis; D053841:Electroosmosis; D019075:Electrophoresis, Capillary / Q000379:methods*; D006801:Humans; D057446:Hydrodynamics; D057625:Isotachophoresis; D008900:Mineral Waters / Q000032:analysis; D009113:Muramidase / Q000032:analysis; D011506:Proteins / Q000032:analysis; D015203:Reproducibility of Results; D012709:Serum Albumin / Q000032:analysis; D016482:Urinalysis; D025101:Vitamin B 6 / Q000032:analysis
chemical_list: D001959:Bromates; D008900:Mineral Waters; D011506:Proteins; D012709:Serum Albumin; D025101:Vitamin B 6; D009113:Muramidase
keywords: Analytes of different origins; Automated electrophoretic analyzer; Complex matrices; Long-term analyses; Stability studies