Method devised for determining low molecular weight organic acids in vinic samples by capillary electrophoresis: validation of the method with real samples

Abstract

The validation has been carried out of a method devised for determining by capillary electrophoresis the low molecular weight organic acids present in various types of vinic sample. The organic acids specifically studied are those most commonly found in samples of vinic origin: formic, fumaric, succinic, oxalic, malic, tartaric, acetic, lactic and citric acids. The electropherograms were obtained using an electrolyte consisting of tetraborate buffer (10 mmol/l) at pH 9.3, an electro-osmotic flow moderator (TTAOH), and Ca²⁺ and Mg²⁺ as complexing agents, for better resolution of some of the acids studied. Other conditions of the method are hydrostatic injection (10 cm height for 30 s), UV detection at a wavelength of 185 nm and temperature of 200 °C.

The method used for the validation was comparison of the slopes of the curves obtained with standards and the regression curves obtained by standard addition. For this comparison, t and F statistics were used.