Use of organic solvent to prevent protein adsorption in CE-MS experiments.
Protein adsorption onto capillary wall often hampers CE separations, particularly in the CZE mode. Electrostatic interactions are not the only factors affecting adsorption, as hydrophobic interactions and/or protein conformational changes are also involved in the adsorption phenomenon. Numerous methods can be used to reduce or avoid adsorption, such as (i) addition of low molecular weight molecules in the BGE, (ii) use of surfactants, or (iii) capillary coatings. However, most of these methods are not MS-compatible. In this study, we evaluated the addition of organic solvent as an alternative MS-compatible method to decrease protein adsorption. The effect of the solvent addition was emphasized using classical methods for estimating reversible and irreversible adsorption. In many cases, organic solvents were effective at decreasing adsorption. However, the influence of the organic solvent on protein adsorption should be evaluated case-by-case in CE method development.
School of Pharmaceutical Sciences, University of Geneva, University of Lausanne, Geneva, Switzerland.
Aline
A
Staub
Sylvain
S
Comte
Serge
S
Rudaz
Jean-Luc
JL
Veuthey
Julie
J
Schappler
D000097:Acetonitriles; D000327:Adsorption; D053841:Electroosmosis; D019075:Electrophoresis, Capillary / Q000379:methods*; D000431:Ethanol; D006863:Hydrogen-Ion Concentration; D057927:Hydrophobic and Hydrophilic Interactions; D000432:Methanol; D008956:Models, Chemical; D009930:Organic Chemicals / Q000737:chemistry*; D011506:Proteins / Q000737:chemistry* / Q000302:isolation & purification; D012997:Solvents / Q000737:chemistry*; D014783:Viscosity
D000097:Acetonitriles; D009930:Organic Chemicals; D011506:Proteins; D012997:Solvents; D000431:Ethanol; D000432:Methanol; C032159:acetonitrile