Confirmation of organophosphorus insecticides by chemical reduction

Abiotic reduction of nitro aromatic pesticides in anaerobic laboratory systems

“…The ratio of retention times for the product peak to methyl parathion was 0.75, which is the same as reported by Adhya et al (1981a) for the aminomethyl parathion to methyl parathion retention time ratio. A procedure for making aminomethyl parathion by reduction of methyl parathion with chromous chloride (Forbes et al, 1975; Volpe and Mallet, 1980) produced a material that gave a mass spectrum consistent with that of aminomethyl parathion and that chromatographed with the same retention time as the product peak. (5) Dark control studies in indigodisulfonate and anthraquinonedisulfonate systems showed that ambient laboratory lighting did not affect the reaction.…”

Confirmation of some nitro group-containing pesticides by chemical reduction and gas chromatography with electrolytic conductivity detection

“…The OV-1 column was also useful for most compounds and results are illustrated in Figures 1 and 2 for trifluralin and dinoseb. The organophosphates were run to compare our electrolytic conductivity results with those obtained earlier by flame photometric (phosphorus) and alkali flame ionization detection under slightly different reaction conditions (Forbes et al, 1975). The conductivity results (Table II) showed that the reduction products were equally or more sensitive than the parent organophosphates and they chromatographed with similar peak shapes.…”

“…Chromous chloride was evaluated along with three other reducing agents for the confirmation of selected organophosphate insecticides which contained the -N02 group (Forbes et al, 1975). It was found that while the parent compounds had strong electron-capture sensitivity, the derivatives, because of the loss of the -N02, were less sensitive by a factor of about 400.…”

Degradation of niclosamide (2',5-dichloro-4'-nitrosalicylanilide) in sediment and water systems

“…[14C]Niclosamide was purified by reverse-phase thin-layer chromatography (TLC) on Whatman KC18 plates using a solvent system of ethanol-water-formic acid (75:25:1) and was diluted with unlabeled niclosamide before use. Aminoniclosamide (2,,5-dichloro-4/-aminosalicylanilide) was synthesized from niclosamide by reduction of the nitro group using chromous chloride (Forbes et al, 1975). The reduction product was recrystallized from benzene and purified by chromatography on a column of Florisil (methanol as the eluting Department of Fisheries and Oceans, Freshwater Institute, Winnipeg, Manitoba, Canada R3T 2N6.…”