Residues of methamidofos, malathion, and methiocarb in greenhouse crops.

The diminution of methamidofos, malathion, and methiocarb in different crops grown in greenhouses has been studied, including the presence of metabolites such as malaoxon, methiocarb sulfoxide, and methiocarb sulfone. The analytical method is based on dichloromethane extraction and GC-PFPD analysis. It has been validated establishing performance parameters such as recovery rates, precision, linear ranges, and limits of detection and quantification, which are low enough for ensuring that their corresponding MLRs can be adequately quantified. Samples of treated cucumbers and peppers grown in greenhouses were collected and analyzed during a 15-day period for obtaining the diminution rates of methamidofos and malathion. The behavior of methiocarb in treated green beans and tomatoes has been studied using analysis of variance (ANOVA) as the statistical tool, for establishing the influence of crop, season, application dose, and greenhouse design.