monocrotophos and acephate

A method combining hydrophilic interaction liquid chromatography (HILIC) with tandem mass spectrometry (MS/MS) was developed for the determination of polar organophosphorus pesticides (OPPs; acephate, methamidophos, monocrotophos, omethoate, oxydemeton-methyl, and vamidothion) in water samples. To extract the polar OPPs and minimize matrix effects from the water sample, an activated carbon cartridge was used for pretreatment. After pretreatment of the water sample, the eluate from the activated carbon cartridge was directly injected into the HILIC/MS/MS system. The OPPs were separated on an Atlantis HILIC silica column by isocratic elution with a mixture of acetonitrile, isopropanol, and ammonium formate buffer as a mobile phase, and they were detected by positive electrospray ionization MS/MS in the selected reaction monitoring mode. The method was validated at 0.05, 0.5, and 5 microg/L levels in water samples, and the recoveries of polar OPPs were between 76.4 and 98.6%. The limits of detection were between 0.13 and 1.0 pg on-column, and the limits of quantification were between 0.43 and 3.4 pg on-column. The method can be applied to the determination of trace amounts of OPPs in environmental water samples.

Topics: 2-Propanol; Acetonitriles; Buffers; Chromatography, Liquid; Dimethoate; Formates; Molecular Structure; Monocrotophos; Organothiophosphorus Compounds; Pesticides; Phosphoramides; Reference Standards; Reproducibility of Results; Sensitivity and Specificity; Solvents; Spectrometry, Mass, Electrospray Ionization; Tandem Mass Spectrometry; Water

Organophosphorus pesticides like monocrotophos, profenofos, chlorpyrifos, and acephate are most commonly used in India for agriculture and public health programs. Previous studies have revealed that at low doses, organophosphorus pesticides not only act as genotoxic agents but also affect several other biochemical pathways. The aim of the current investigation was to assess apoptosis and necrosis caused by these pesticides on human peripheral blood lymphocytes under in vitro conditions using the DNA diffusion assay. Our studies have revealed that all the above pesticides induced apoptosis and necrosis in cultured human peripheral blood lymphocytes in in vitro conditions. The results are statistically significant (p < 0.001). Data on these alterations of immune cells are required for understanding the subchronic effects mediated by pesticides on nontarget organisms.

Topics: Apoptosis; Cells, Cultured; Chlorpyrifos; Diffusion; DNA; DNA Damage; Dose-Response Relationship, Drug; Humans; Insecticides; Leukocytes, Mononuclear; Monocrotophos; Necrosis; Organophosphorus Compounds; Organothiophosphates; Organothiophosphorus Compounds; Phosphoramides

The fruit fly Dacus ciliatus Loew is a pest of the fruits of many cucurbit species. We studied the effect of organaophosphate and pyrethroid compounds on the adult flies by using surface contact and oral administration. In contrast to other fruit flies, we found that organophosphates were ineffective against D. ciliatus. This was supported by the insignificant decrease of head acetylcholinesterase activity. All tested pyrethroids showed satisfactory killing ability, rapid and massive knockdown effect, and prevention of oviposition. Piperonyl butoxide considerably increased the toxicity of pyrethroids, which can be explained by oxidase detoxification of these compounds in D. ciliatus. It can be concluded that pyrethroids have high potential for controlling D. ciliatus.

Topics: Acetylcholinesterase; Animals; Biological Assay; Dimethoate; Diptera; Female; Fertility; Insect Control; Insecticides; Malathion; Male; Monocrotophos; Organothiophosphorus Compounds; Phosphoramides; Pyrethrins