Residues of Methamidofos, Malathion, and Methiocarb in Greenhouse Crops

Abstract

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.

Characterization of a fungal strain capable of degrading chlorpyrifos and its use in detoxification of the insecticide on vegetables

“…On the other hand, some insect pests and pathogens may also develop resistance or tolerance to the conventionally used pesticides due to their single mode of action and this leads to frequent application of pesticides at higher dosages (Gajbhiye 2004). Furthermore, pesticides often dissipate slower on greenhouse vegetables due to the hermetic environments in greenhouses (Aguilera-del Real et al 1999;Garau et al 2002;Hernandez Torres et al 2002;Martinez Galera et al 2003). The excessive and frequent application of pesticides may result in high levels of pesticide residues accumulated on vegetable products, which poses a potential health hazard to consumers (Bolognesi & Morasso 2000;Fan & Jackson 1989;Tweedy et al 1991).…”

An ultrasensitive “mix-and-detect” kind of fluorescent biosensor for malaoxon detection using the AChE-ATCh-Ag-GO system

“…3 Malaoxon, a potent metabolite, can result from hydrolysis in high/low relative humidity conditions, causing thion to oxidize into oxon compounds on water and fruit/vegetable surfaces. 4,5 Malaoxon's toxic effects result from inhibiting the enzyme acetylcholinesterase (AChE), leading to an accumulation of acetylcholine (ACh), which can overstimulate muscarinic and nicotinic receptors, resulting in cholinergic toxic manifestations and ultimately death. Malaoxon is 40 times more toxic than malathion and other metabolites, making it a serious health hazard.…”

Evaluación del Riego Ambiental del Insecticida Metamidofos en Bioensayos con Cuatro Organismos Acuáticos no Destinatarios

“…El insecticida organofosforado metamidofos es un acaricida de acción sistémica, de contacto y con alto poder residual (Wu et al, 2001;Hernández et al, 2002;Ismail et al, 2002). Es altamente tóxico para el hombre por vía oral, dérmica y por inhalación (Sosa-Gomez et al, 2001;Evaristo y Baptista, 2002;He et al, 2002;Bouchard et al, 2006).…”