Determination of lactose in sugar-free milk powder by capillary electrophoresis with electrochemical detection

Lactose in three sugar-free milk powder samples were satisfactorily determined by capillary electrophoresis with electrochemical detection using a 300 mum copper disk electrode as the working electrode in 0.1 mol/l NaOH medium. There was acceptable linearity (0.9969) between the peak current and concentration of lactose in the range from 5.0x10(-6) to 5.0x10(-3) g/ml with the detection limit (S/N = 3) of 1x10(-7)g/ml. The proposed method was successfully applied to analyze the actual milk powder samples. (C) 2001 Elsevier Science Ltd. All rights reserved.