Detection of unintended stress effects on tomato fruits treated with carbofuran by application of chemometric techniques to LC-MS data

MARÍA CULZONI,; SANCHEZ PEREZ I; GIL GARCÍA, MARÍA; SANCHEZ PEREZ EM; LOPEZ ORTIZ F; MARTINEZ GALERA, MARIA; GOICOECHEA, HÉCTOR C

SANTA FE

Workshop; 2º Latin American Pesticide Residue Workshop, Food and Environment; 2009

A chemometric strategy based on multivariate curve resolution and alternating least squares (MCR-ALS) applied to LC-MS three-way data has been developed to perform a metabonomic study on tomato, “Rambo” variety treated with carbofuran. This insecticide belongs to the family of carbamates, has nematicide, insecticide and miticide activity and is communly used in greenhouse crops.The main goal of this work was to study the behavior of different components (endogenous metabolites) in the tomato fruit and to connect possible changes with the presence of pesticide. According to this purpose, an exhaustive comparison of the individual concentration profiles of all the principal components present in treated samples with the concentration profiles of the same components in blank samples was carried out.This methodology based in the LC-MS analysis of different samples harvested during a period of 21 days after the treatment with the pesticide, (previously extracted with QuECHERS method), followed by MCR-ALS analysis of the data has proved to be adequate for the detection of unintended stress effects due to the previous treatment with this pesticide. In this way, it was able to obtain the concentration and MS spectra profiles of the main components (previously estimated with SVD algorithm) for samples treated with pesticide and for blank samples, showing how they changes thorough the time.Thus, different degradation profiles were found for the same metabolites in treated and no treated samples, which demonstrate that the presence of pesticide causes changes thorough the time in the behavior of certain endogenous tomato metabolites as the result of a physiological stress situation. Degradation profiles were obtained from of the concentration profiles extracted by MCR-ALS augmented matrices analysis and their identity was confirmed by comparing their MS spectra profiles.