SIMULTANEOUS DETERMINATION OF FORMIC ACID, ACETIC ACID, PROPIONIC ACID AND BUTYRIC ACID BY CAPILLARY ELECTROPHOESIS WITH CAPACITIVELY COUPLED CONTACTLESS CONDUCTIVITY DETECTION (CE-C4D)

Abstract

    Capillary electrophoresis is an effective and simple method for rapid determination of organic acids in different kind of samples, including food sample. Four organic acids, including Formic acid, Acetic acid, Propionic acid and Butyric acid, were separated using fused-silica capillary of 50μm I.D and total length of 50cm. The separation voltage was -18 kV. The separation was performed in less than six minutes with electrolyte solution consisting of 30mM L-histidine and 40mM Mes (2-(N-morpholino) ethanesulfonic) (pH 5.8). Detection limits of 10-6M and 2.10-6M were achieved for Formic acid and Acetic acid, Propionic acid, Butyric acid, respectively. The method was applied for the determination of target acids in coffee, red wine and soft drink samples.

Keywords: Formic acid, Acetic acid, Propionic acid, Butyric acid, capillary electrophoresis (CE), capacitively coupled contactless conductivity detection (C4D)