For connecting flow-through analytical methods with capillary electrophoresis, a chip working in the air-assisted flow gating interface regime is cast from poly(dimethylsiloxane). In the injection space, the exit from the delivery capillary is placed close to the entrance to the separation capillary. Prior to injecting the sample into the separation capillary, the background electrolyte is forced out of the injection space by a stream of air. In the empty space, a drop of the sample with a volume of <100 nL is formed between the exit from the delivery capillary and the entrance into the separation capillary, from which the sample is injected hydrodynamically into the separation capillary. After injection, the injection space is filled with BGE, and the separation can be begun. Three geometric variants for the mutual geometric arrangement of the delivery and separation capillaries were tested: the delivery capillary is placed perpendicular to the separation capillary, from either above or below, or the capillaries are placed axially, that is, directly opposite one another. All of the variants are equivalent from the analytical and separation efficiency viewpoints. The repeatability expressed by RSD is up to 5%. The tested flow gating interface variants are also suitable for continuous and discontinuous sampling at flow rates of the order of units of μL/min. The developed instrument for sequential electrophoretic analysis operates fully automatically and is suitable for rapid sequential monitoring of dynamic processes.

Department of Hygiene 3rd Faculty of Medicine Charles University Prague Czechia

Faculty of Science Department of Analytical Chemistry Charles University Prague Czechia

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Kubáň, P., Hauser, P. C., Electrophoresis 2019, 40, 124-139.

Kubáň, P., Hauser, P. C., TrAC Trends Anal. Chem. 2018, 102, 311-321.

Šolínová, V., Kašička, V., J. Sep. Sci. 2006, 29, 1743-1762.

Tůma, P., Sommerová, B., Šiklová, M., Talanta 2019, 192, 380-386.

Furter, J. S., Boillat, M. A., Hauser, P. C., Electrophoresis 2020, 41, 2075-2082.

Ranjbar, L., Foley, J. P., Breadmore, M. C., Anal. Chim. Acta 2017, 950, 7-31.

Kler, P. A., Sydes, D., Huhn, C., Anal. Bioanal. Chem. 2015, 407, 119-138.

Kohl, F. J., Sanchez-Hernandez, L., Neususs, C., Electrophoresis 2015, 36, 144-158.

Ramautar, R., Somsen, G. W., de Jong, G. J., Electrophoresis 2016, 37, 35-44.

Tempels, F. W. A., Underberg, W. J. M., Somsen, G. W., de Jong, G. J., Electrophoresis 2008, 29, 108-128.

Gong, M. J., Zhang, N., Maddukuri, N., Anal. Methods 2018, 10, 3131-3143.

Lemmo, A. V., Jorgenson, J. W., Anal. Chem. 1993, 65, 1576-1581.

Lada, M. W., Kennedy, R. T., Anal. Chem. 1996, 68, 2790-2797.

Hooker, T. F., Jorgenson, J. W., Anal. Chem. 1997, 69, 4134-4142.

Lewis, K. C., Opiteck, G. J., Jorgenson, J. W., Sheeley, D. M., J. Am. Soc. Mass Spectrom. 1997, 8, 495-500.

Zhang, Q. Y., Gong, M. J., J. Chromatogr. A 2014, 1324, 231-237.

Unger, M. A., Chou, H. P., Thorsen, T., Scherer, A., Quake, S. R., Science 2000, 288, 113-116.

Zhang, Q. D., Zhang, M., Djeghlaf, L., Bataille, J., Gamby, J., Haghiri-Gosnet, A. M., Pallandre, A., Electrophoresis 2017, 38, 953-976.

Opekar, F., Tůma, P., Electrophoresis 2019, 40, 587-590.

Opekar, F., Tůma, P., Anal. Chim. Acta 2018, 1042, 133-140.

Opekar, F., Tůma, P., Talanta 2020, 219, 121252.

Liénard-Mayor, T., Taverna, M., Descroix, S., Mai, T. D., Anal. Chim. Acta 2020. https://doi.org/10.1016/j.aca.2020.09.008.

Opekar, F., Coufal, P., Štulík, K., Chem. Rev. 2009, 109, 4487-4499.

Opekar, F., Tůma, P., J. Chromatogr. A 2016, 1446, 158-163.

Makrlíková, A., Opekar, F., Tůma, P., Electrophoresis 2015, 36, 1962-1968.

Opekar, F., Nesměrák, K., Tůma, P., Electrophoresis 2016, 37, 595-600.

Tůma, P., J. Sep. Sci. 2017, 40, 940-947.

Opekar, F., Tůma, P., J. Chromatogr. A 2017, 1480, 93-98.

Miller, J. C., Miller, J. N., Statistics and Chemometrics for Analytical Chemistry, Pearson Education Limited, Harlow, England, 2010.