Decomposition of Di-Syston (O,O-diethyl S-[2-(ethylthio)ethyl] phosphorodithioate) on fertilizers by infrared, gas-liquid chromatography, and thin-layer chromatography

Mobility and degradation of disulfoton in coffee culture soil

“…However, this same conversion may occur indirectly, where the first AODST is converted into AODSO which, in turn, becomes quickly AODSA. These results do not support the proposal from Ibrahim et al (1969) and Szeto et al (1983), suggesting a different degradation route. The new route of degradation proposed in this paper is shown in Fig.…”

“…Table 3 shows the total amounts of the compounds found in each study. It is noted that for the standard DST solution, oxidation of DST the DSO, DSA, and AODSA follows the route proposed by Ibrahim et al (1969), except for the AODSO, which was not detected in this experiment, whose detection limit is 0.5 mg/L. We also observed that in the course of the study the percentage of AODST was decreased, while the AODSA content was increased.…”

“…In its pure form it is a colorless liquid with sulfur odor, boiling point equal to 128°C (at 1.33 hPa), density equal to 1.14 g/cm 3 and water solubility of 15 mg/L at 20°C (Pesticide Documents, 2014). In formulations, the DST is found in the form of granules which are applied directly to the soil, where the active ingredient released from the beads may contaminate the environment due to the accumulation or degradation of the insecticide (Ibrahim et al, 1969;Usui et al, 2012;Kalbe et al, 2014).…”

“…Although the organophosphorus compounds usually present rapid degradation processes and relatively short life in the environment, the acute toxic effects on non-target insects and the ability to reach the surface water or groundwater via Ibrahim et al (1969). rainwater and irrigation increases the probability of ecosystem contamination (Chen and Huang, 2006;Hernández et al, 2008;Salemi et al, 2013). Thus, obtaining data on mobility and degradation of organophosphates is essential to predict the levels of waste that might remain in the soil, assess the risks of leaching to the aquatic environment and determine the toxicity of the waste (González-Curbelo et al, 2013;Chai et al, 2013).…”

“…Extraction techniques such as solid-liquid extraction (Caldas et al, 2011), cloud point extraction (Faria et al, 2007) and solid phase extraction (SPE) hyphenated with dispersive liquid-liquid microextraction (DLLME, Naeeni et al, 2011), have been employed in the extraction of these soil matrices and water for subsequent detection and quantification by gas chromatography. Ibrahim et al (1969) suggested a route for the DST degradation in the soil, obtaining as end-product the oxygenated disulfoton sulfone analogue (AODSA) (Fig. 1).…”