ANALYSIS OF CYCLOPIAZONIC ACID IN MILK BY CAPILLARY ELECTROPHORESIS

A Micellar Electrokinetic Capillary Chromatography (MEKC) method to de tect cyclopiazonic acid (CPA) in milk and compare its quantifying effi ciency to the Reverse Phase Liquid Chromatography (RPLC) method was ev aluated. Alkaline milk samples were defatted, then acidified before be ing twice liquid-liquid extracted with chloroform. Bare fused-silica c apillary-extended light path with 50 mu m 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 (cor relation coefficient, r=0.99995). Recoveries of spiked CPA in milk wer e 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 ME KC was 0.27 x 10(-07) pg ml(-1). Capillary electrophoresis (MEKC) is a better and rapid method for CPA detection in milk. (C) 1998 Elsevier Science Ltd. All right reserved.