Photochemistry of oxime carbamates. 1. Phototransformations of aldicarb

Studies on Removal Efficiency of Rice Bran for Pesticides.

“…Therefore, it is necessary to limit the chemical substances discharged into the environment as much as possible, and also to remove them as completely as possible. To remove pesticides from water in the environment, photochemical decomposition by ultraviolet irradiation, [4][5][6] ozonation 7) or alkaline hydrolysis 8,9) have usually been used. One problem with these methods is cost.…”

Formation of fluorophores from nitrogenous pesticides by photolysis and reaction with OPA-2-mercaptoethanol for fluorescence detection in liquid chromatography

“…Relative fluorescence was very dependent upon the solvents used as noted earlier, showing that the solute environment was important in the photolysis mechanism. It has been reported that the presence and/or absence of oxygen affects the rate and products formed from some pesticides (Freeman and McCarthy, 1984;Freeman and Ndip, 1984). Even though the solvents used in this investigation were purged with helium to avoid bubble forma-tion during chromatography, the oxygen permeability of Teflon (Poulsen et al, 1986) prevented deoxygenation from being achieved during the entire photolysis reaction.…”

“…Further, the ability of the micellar structure to partition analyte from the aqueous phase into the organic phase increases very significantly. Aldicarb and methomyl have been shown to produce significant amounts of methylamine after photolysis in acetonitrile solutions (Freeman and McCarthy, 1984;Freeman and Ndip, 1984). Luchtefeld (1985) proposed that several phenylurea herbicides produce methylamine upon photolysis.…”

Postcolumn photolysis of pesticides for fluorometric determination by high-performance liquid chromatography

“…Relative fluorescence was very dependent upon the solvent used, suggesting that the solute environment was important in the photolysis mechanism. It has been reported that the presence and/or absence of oxygen affects the rate and products formed from some pesticides (12)(13)(14)(15). The solvents used here were purged with helium to avoid bubble formation during chromatography, but because of the oxygen permeability of Teflon (16), deoxygenation was not achieved during the entire photolysis reaction.…”

“…Such solvents were avoided because they required that the photolysis coil be replaced. Aldicarb and methomyl have been shown to produce significant amounts of methylamine after photolysis in acetonitrile solutions (12,13). Also, monuron and fenuron produced dimethylamine after photolysis in deoxygenated methanol (14), and Luchtefeld (6) proposed that several phenylurea herbicides produce methylamine upon photolysis.…”