145307-19-3Relevant academic research and scientific papers
Degradation behavior and products of malathion and chlorpyrifos spiked in apple juice by ultrasonic treatment
Zhang, Yuanyuan,Xiao, Zhiyong,Chen, Fang,Ge, Yiqiang,Wu, Jihong,Hu, Xiaosong
, p. 72 - 77 (2010)
Apple juice (13 °Brix) spiked with malathion and chlorpyrifos (2-3 mg l-1 of each compound) was treated under different ultrasonic irradiations. Results showed that ultrasonic treatment was effective for the degradation of malathion and chlorpyrifos in apple juice, and the output power and treatment time significantly influenced the degradation of both pesticides (p 2 ≥ 0.90). The kinetics parameters indicated that chlorpyrifos was much more labile to ultrasonic treatment than malathion. Furthermore, malaoxon and chlorpyrifos oxon were identified as the degradation products of malathion and chlorpyrifos by gas chromatography-mass spectrometry (GC-MS), respectively. The oxidation pathway through the hydroxyl radical attack on the P{double bond, long}S bond of pesticide molecules was proposed.
Effect of chlorination on anti-acetylcholinesterase activity of organophosphorus insecticide solutions and contributions of the parent insecticides and their oxons to the activity
Fujita, Yuki,Huang, Yuxiang,Matsui, Yoshihiko,Matsushita, Taku,Omori, Kei,Shirasaki, Nobutaka
, (2020/07/31)
Organophosphorus insecticides are known to be partly transformed to their respective oxons during the chlorination step of drinking water treatment. For most organophosphorus insecticides, the toxicological endpoint for determining acceptable daily intake levels is inhibition of acetylcholinesterase (AChE). Like the parent insecticides, oxons also inhibit AChE, so the presence of oxons in drinking water is also evaluated. However, no attention is paid to the possible presence of transformation products (TPs) other than oxons. In the present study, we determined whether the anti-AChE activity observed for chlorinated solutions of the organophosphorus insecticides malathion and methidathion could be solely attributed to the parent compounds and their oxons. Upon chlorination, both malathion and methidathion were immediately transformed to their oxons; the maximum transformation ratios were 60percent and 30percent, respectively, indicating that at least 40percent and 70percent of these compounds were transformed into other TPs. Before chlorination, malathion- and methidathion-containing solutions exhibited little to no anti-AChE activity, but the solutions showed strong activity after chlorination. The contributions of the parent insecticides and their oxons to the activities of the chlorinated samples were calculated from the concentrations of the compounds in the samples and dose–response curves for chemical standards of the compounds. For both the malathion-containing solution and the methidathion-containing solution, the calculated anti-AChE activities were almost the same as the observed activities at every chlorination time. This suggests that the observed activities could be attributed solely to the parent insecticides and their oxons, indicating that other TPs need not be considered.
A new method for the determination of some organophosphate insecticides
Tiwari, Ashok Kumar,Dubey, Bijyendra Kumar,Shukla
, p. 717 - 719 (2007/10/03)
A quick and convenient method has been developed for milligram determination of some organophosphate insecticides. The sample is allowed to react with a calculated excess of (0.1 N) chloramine-T reagent in the presence of glacial acetic acid for 10-15 min at room temperature. After the reaction is over, KI solution (10%) is added and the unreacted reagent is back-titrated with 1 N solution of sodium thiosulfate to starch end-point. The method is applied for the determination of technical preparations of malathion (95%), dimethoate (90%), ethion (95%) and phorate (97%). The results are within the error of ±1.0%.
