Dichlorvos structure

Prepared by bulk polymerization, an MIP for the detection of dicrotophos based on the Eu3+ complex has recently been presented [58]. The authors used reversible addition fragmentation chain transfer (RAFT) polymerization followed by ring closing methathesis (RCM) to obtain the star MIP with arms made out of block copolymer. The star MIP containing Eu3+ exhibited strong fluorescence when excited at 338 nm with a very narrow emission peak (half width -10 nm) at 614 nm. This MIP was sensitive to dicrotophos in the range of 0-200 ppb, but showed saturation above this limit. Cross-reactivity of this MIP was evaluated with respect to structurally similar compounds dichlorvos, diazinon and dimethyl methylphosphonate. In these tests no optical response of the polymer was detected even at concentrations much higher than the initial concentration of dicrotophos (>1000 ppb). 

Different OP compounds have structural similarities within classes. The phosphorus compounds have the characteristic phosphoryl bond, P=0. Most OP compounds have a phosphoryl bond or a thiophosphoryl bond (P=S). All OP compounds are esters of phosphorus with varying combinations of oxygen, carbon, sulfur, and nitrogen attached. These are classified as (1) phosphates (2) phos-phonates (3) phosphorothioates (4) phosphorodithioates (5) phosphorothiolates and (6) phosphoramidates. Further, the OP compounds are categorized as (1) aliphatic (2) phenyl and (3) heterocyclic derivatives. The aliphatic are carbon chainlike in structure. TEPP, which was used in agriculture for the first time in 1946, is a member of this group. Others include malathion, trichlorfon, monocrotophos, dimethoate, oxydemetonmethyl, dimethoate, dicrotophos, disulfoton, dichlorvos, mevinphos, methamidophos, and acephate. 

There are few insecticides in this subclass, but many other subclasses become true phosphates during metabolism by various organisms. A typical structure is represented by dichlorvos, which is used in pet flea collars. Its oral LD50 in rats is 56-80 mg/kg. 

Das, Y.T., P.K. Taskar, H.D. Brown and S.K. Chattopadhyay (1983). Exposure of professional pest control operators to dichlorvos (DDVP) and residue on house structures, Toxicol. Lett., 17, 95-99. 

Scheme /13 Compared structures of the insecticide Dichlorvos and a parent compound containing the 2,2-dichlorovinyloxycarbonyl unit...

Applicators and residents of dichlorvos (DDVP) treated structures were monitored for evidence of insecticide exposure using exposure pads, air samplers, serum and red blood cell acetylcholinesterase (AChE) tests, and urine analysis. There was no evidence of DDVP or dichloroacetic acid (DCAA) in the urine of applicators or cooperators. There were slight but significant differences (Pi0.05) in serum AChE activity of residents of treated units, but erythrocyte AChE was unchanged. Applicator AChE test results were inconclusive. It was concluded that there was not a significant risk. In terms of acute toxicity, to either the pesticide applicators or the residents of treated structures. 

Twenty residential structures were treated with dichlorvos insecticide (DDVP) for (Serman cockroach control. Dermal exposure pads, air samplers, blood tests for sensn and erythrocyte acetyl-ciiolinesterase (oizyme) activity and urine analyses were used to monitor both c licators and residents for evidence of 9qx>sure to EDVP. 

Yao and Hsieh (1974) observed that treatment of A. parasiticus with dichlorvos [0,0-dimethyl-0-(2,2-dichlorovinyl)phosphate] resulted in reduced aflatoxigenicity and in the formation of an orange-red pigment, called versiconal acetate (19). Structure elucidation using and NMR techniques on versiconal acetate (Cox et al., 1977 Steyn et al., 1979a) and... 

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