Separation and Sensitive Detection of α-Lactalbumin and β-Lactoglobulin by Capillary Zone Electrophoresis

alpha-lactalbumin and beta-lactoglobulin are main impurities in the lactose products extracted from whey, which may cause allergy. Therefore, the separation and detection of race alpha-lactalbumin and beta-lactoglobulin are of great importance to food and pharmaceutical industry. In this work, a simple, fast, sensitive and reproducible capillary zone electrophoresis (CZE) method has been developed for this purpose. After simple sample preparation procedure, alpha-lactalbumin and beta-lactoglobulin can be baseline separated within 2 minutes under following conditions: 25 mM phosphate buffer at pH 7. 0, +30 kV applied voltage, 25 degrees C capillary temperature, 205 nm UV detection, and sample injection at 50 mbar for 10 s(o). The limit of detection (LOD) at 3 times of S/N is 3. 0 and 12 mg/L for alpha-lactalbumin and beta-lactoglobulin, respectively. The repeatability (RSD, n = 6) is below 1% for migration time and below 6% for peak area. These data qualified the method to the analysis of real lactose samples. The proposed method also shows a great potential in other fields of food and pharmaceutical industry.