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

MARÍA J. CULZONI; ISIDRO SÁNCHEZ PÉREZ; MARÍA D. GIL GARCÍA; ESTELA M. SÁNCHEZ PÉREZ; FERNANDO LÓPEZ-ORTIZ; MARÍA MARTÍNEZ GALERA ; HÉCTOR C. GOICOECHEA

Workshop; 2nd Latin America Pesticide Residue Workshop (LAPRW2009) – Pesticides in Food and Environmental Samples; 2009

A chemometric strategy based on multivariate curve resolution alternating least squares (MCR-ALS) applied to LC-MS three-way data has been developed to perform a metabonomic study on Rambo cultivar tomatoes treated with carbofuran. This insecticide belongs to the family of carbamates, has nematicide, insecticide and miticide activity and is commonly 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. The applied methodology consists 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) and MCR-ALS analysis of the data. This procedure has proved to be adequate for the detection of unintended stress effects due to the previous treatment with this pesticide. In this way, the methodology provided us the concentration and MS spectra profiles of the main components for samples treated with pesticide and for blank samples, showing significant changes through the time. Thus, different profiles were found for the same metabolites in treated and no treated samples, which demonstrate that the presence of pesticide causes changes through the time in the behavior of certain endogenous tomato metabolites as the result of a physiological stress situation. Identity of metabolite profiles (extracted by MCR-ALS analysis) was confirmed by comparing their MS spectra.