Capillary electrophoresis of alpha-lactalbumin in milk powders

A quick and simple method for the extraction and analysis of alpha-lactalbumin in milk protein powders is presented, which permits accurate duty classification of commercial products as required under the U.S. Harmonized Tariff System. An acetic acid buffer medium is utilized to extract the whey proteins, which are then analyzed by capillary electrophoresis using an electrokinetic injection onto an uncoated column. The running buffer is composed of a 50 mM borate buffer at pH 8.0. The separation is rapid (<5 min) and displays good limits of detection (+/-0.01 mg mL(-1)). Overall, the method provides a simple means for extracting and analyzing alpha-lactalbumin in milk powders.