title: Analysis of major milk whey proteins by immunoaffinity capillary electrophoresis coupled with MALDI-MS.
abstract: Two major milk whey proteins, β-lactoglobulin and α-lactalbumin, are among the main cow milk allergens and can cause allergy even at a very low concentrations. Therefore, these proteins are interesting targets in food analysis, not only for food quality control but also for highlighting the presence of allergens. Herein, a sensitive analysis for β-lactoglobulin and α-lactalbumin was developed using immunoaffinity capillary electrophoresis hyphenated with MALDI-MS. Magnetic beads functionalized with appropriate antibodies were used for β-lactoglobulin and α-lactalbumin immunocapture inside the capillary. After elution from the beads, analyte focusing and separation were performed by transient isotachophoresis followed by MALDI-MS analysis performed through an automated iontophoretic fraction collection interface. A LOD in the low nanomolar range was attained for both whey proteins. The method developed was further applied to the analysis of different milk samples including fortified soy milk.
authors.affiliation: Laboratoire d'Electrochimie Physique et Analytique, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.
authors.forename: Natalia
authors.initials: N
authors.lastname: Gasilova
authors.forename: Anne-Laure
authors.initials: AL
authors.lastname: Gassner
authors.forename: Hubert H
authors.initials: HH
authors.lastname: Girault
mesh_terms: D000818:Animals; D002417:Cattle; D019075:Electrophoresis, Capillary / Q000379:methods*; D007118:Immunoassay / Q000379:methods*; D057625:Isotachophoresis; D057230:Limit of Detection; D058185:Magnetite Nanoparticles / Q000737:chemistry; D008892:Milk / Q000737:chemistry; D008894:Milk Proteins / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification; D041942:Soy Milk / Q000737:chemistry; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*
chemical_list: D058185:Magnetite Nanoparticles; D008894:Milk Proteins