A simple analytical method for characterization of food proteins by ca
pillary electrophoresis (CE) has been developed. Major proteins in chi
cken eggs and cow's milk are characterized and can be quantitated by t
he CE technique. Egg white proteins are well resolved while the yolk s
hows a substantially more complex protein separation pattern than that
in the egg white. Caseins and whey proteins in fresh milk were resolv
ed by CE in a similar buffer system. Separation of both milk and egg p
roteins was performed reliably and reproducibly in an untreated fused-
silica column, 25 cm x 20 mu m I.D. Diluted egg or milk samples can be
directly loaded on an automated instrument with on-line injection, de
tection and real-time data analysis in less than 10 min.