Evaluation of pesticide residues in open field and greenhouse tomatoes from Colombia

The presence of 17 pesticide residues was determined in just-picked tomatoes coming from open field and greenhouse farms in Colombia. Pesticide residues were quantified through a multiresidue method using ultra performance liquid chromatograph coupled to mass spectrometer. The results give no clear indication about which farming system is producing the most contaminated tomatoes. While the share of open field samples violating the maximum residue limits (MRLs) was higher, the presence of more than one pesticide per sample was detected in a higher number of greenhouse samples. Results showed that all positive samples for acephate exceeded the recommended MRL, indicating indiscriminate use of this insecticide. In both farming systems, the pre-harvest intervals are not respected due to the management practices applied and the continuous ripening of the fruit, once the harvest starts. The results of the present study confirm the need for a monitoring program, actually inexistent, focused in the food commodities consumed locally. (C) 2012 Elsevier Ltd. All rights reserved.