Comparación de dos métodos de extracción y detección cromatográfica de ácido tenuazónico a partir de muestras de tomate

Abstract

This paper evaluates two methods of chromatographic detection and two methods of tenuazonic acid (TA) extraction from tomato paste. Chromatographic detection using a binary mobile phase consisting of acetonitrile and phosphate buffer, at pH 3, was compared to a mobile phase consisting of a gradient of water and acetonitrile in presence of trifluoracetic acid. The best chromatographic results were obtained with the mobile phase of acetonitrile and phosphate buffer, which showed a lower retention time (8.2 min) and greater sensitivity (quantification limit of 1.5 μg/ml). TA extraction and clean-up from tomato samples was performed using either a solid phase extraction method or a defating and partitioning extraction method with organic solvents. Regarding TA extraction and clean-up, a clearer chromatogram was obtained using the solid phase extraction method, with a detection limit of 1 μg/g in tomato samples. However, the defating and partitioning extraction method, besides being cumbersome, had a low performance because of the co-extraction of components from the samples that made it difficult the chromatographic interpretation.