Analysis of cyclopiazonic acid in milk by capillary electrophoresis

A Micellar Electrokinetic Capillary Chromatography (MEKC) method to detect cyclopiazonic acid (CPA) in milk and compare its quantifying efficiency to the Reverse Phase Liquid Chromatography (RPLC) method was evaluated. Alkaline milk samples were defatted, then acidified before being twice liquid–liquid extracted with chloroform. Bare fused-silica capillary-extended light path with 50 μm i.d. and Nova-pak C18-column, were used for the CPA separation in MEKC and RPLC respectively. The analytical response was linear from 40 ppb to 100 ppm CPA in MEKC (correlation coefficient, r=0.99995). Recoveries of spiked CPA in milk were 78–81% over the range of 20 ppb to 500 ppb in MEKC and 71–80% in the range of 50 ppb to 500 ppb in RPLC. The detectable limit of CPA by MEKC was 0.27×10−07 pg ml−1. Capillary electrophoresis (MEKC) is a better and rapid method for CPA detection in milk.