title: Loading capacity of carrier ampholytes--based buffers in capillary electrophoresis.
abstract: Narrow pH cuts of carrier ampholytes (CAs), originally designed for IEF, have been used as BGEs in CE. Their physicochemical properties, rather high buffering capacity and low conductivity, allow very efficient protein separations under high electric field strength. Due to their isoelectric properties, CA BGEs are expected to present a low ionic concentration and consequently a low loading capacity. In this study, we developed a simple method that allows the estimation of the loading capacity of a UV-absorbing BGE by CE. We first characterized in terms of loading capacity, classical ammediol-chromate UV-absorbing BGEs and a 10 mM histidine solution, a classical isoelectric buffer. Then, the loading capacity of four different CA-based BGEs has been assessed. Experimental results have shown that the CA-based buffers were presenting a rather high loading capacity, comparable to classical buffer ones and far higher than the one of the 10 mM histidine solution.
authors.affiliation: Laboratory of Environment and Analytical Chemistry, ESPCI, Paris, France. jean-marc.busnel@espci.fr
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Busnel
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Descroix
authors.forename: Dominique
authors.initials: D
authors.lastname: Godfrin
authors.forename: Marie-Claire
authors.initials: MC
authors.lastname: Hennion
authors.forename: Gabriel
authors.initials: G
authors.lastname: Peltre
mesh_terms: D002021:Buffers; D019075:Electrophoresis, Capillary / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D013056:Spectrophotometry, Ultraviolet
chemical_list: D002021:Buffers