Pesticides mevinphos

EPA pesticide chemical code 011501, see 2-Butoxyethanol EPA pesticide chemical code 011601, see Ethanolamine EPA pesticide chemical code 015602, see Camphor EPA pesticide chemical code 015801, see Mevinphos EPA pesticide chemical code 016401, see Carbon disulfide EPA pesticide chemical code 016501, see Carbon tetrachloride... 

Five organophosphorus pesticides were chosen that could be iso-thermally and simultaneously analyzed by gas chromatography using an N-P TSD detector. They are all currently commercially used and exhibit a wide range of physicochemical properties (Table I). Also influencing the choice of these pesticides was the fact that volatilization data measured from soil and water under controlled laboratory conditions are scarce for methyl parathion, parathion, and diazinon (14-17), and are not available for malathion and mevinphos. Technical mevinphos (60% E-isomer, Shell Development Co.), diazinon (87.2%, Ciba-Geigy Corp.), and malathion (93.3%, American Cyanamld), and analytical grade methyl parathion (99%, Monsanto) and parathion (98%, Stauffer Chemical Co.) were used. 

Figure 2. Experimentally determined and EXAMS predicted percents volatilized (in one day) for five organophosphorus pesticides incorporated into water, water-soil, and soil systems. Computer predictions are not shown for mevinphos or for dry soil.

The relative importance of the two processes in a model evaporation pond, along with the time lor 97% loss of the applied pesticide (system purification time), were calculated (Table V). This calculation confirmed that mevinphos and malathion dissipated primarily by hydrolysis, with malathion the more rapid of these two chemicals. For methyl and ethyl parathion, both processes were significant, although volatilization was the dominant dissipation route. However, since both processes were relatively slow for these pesticides, the purification time was fairly long. Diazinon was predicted to be lost primarily via volatilization, and the purification time was relatively short. 

In order to more closely represent the volatilization environment that would be encountered in an evaporation pond, Triton X-100, a non-ionic emulsifier similar to those used in some pesticide formulations, was added to prepared pesticide solutions at 1000 ppm. The presence of this emulsifier caused a decrease in the percent pesticide volatilized in one day in all cases except for mevinphos (Table VI). Three mechanisms are probably in operation here. First, Triton X-100 micelles will exist in solution because its concentration of 1000 ppm is well above its critical micelle concentration of 194 ppm (30). Pesticide may partition into these micelles, reducing the free concentration in water available for volatilization, which will in turn reduce the Henry s law constant for the chemical (31). Second, the pesticides may exhibit an affinity for the thin film of Triton that exists on the water surface. One can no longer assume that equilibrium exists across the air-water interface, and a Triton X-100 surface film resistance... 

In two cases of moderate intoxication from mevinphos, urinary excretion of dimethylphos-phate (a metabolite of mevinphos) was almost complete 50 hours after exposure/ Although a number of other organophosphorus pesticides also yield dimethyl phosphate, the presence of significant amounts of this metabolite in the urine may be useful in estimating the absorption of mevinphos. 

World Health Organization 919. Mevinphos (Pesticide Residues in Food 1996 Evaluations Part II. Toxicological), pp 1-20. Geneva, International Programme on Chemical Safety (IPCS), 1996... 

Organochlorine pesticides are defined as fat soluble. Most have a log Pm. over 5 (aldrin, DDE, DDT, dieldrin, endrin, and heptachlor), and the HCH isomers have a log Pm. in the 3-4 range. The majority of the OPPs are also classified as fat soluble but present lower values of log Pow. Chlorfenvinphos, fenitrothion, and diazinon, with a log P[Pg.718]

Air analysis for some of the individual pesticides of this class has been published by NIOSH. These pesticides include mevinphos, TEPP, ronnel, malathion, parathion, EPN, and demeton (NIOSH Methods 2503, 2504, 1450). In general, pesticides in air may be trapped over various filters, such as Chro-mosorb 102, cellulose ester, XAD-2, PTFE membrane (1 pm), or a glass fiber filter. The analyte(s) are extracted from the filter or the sorbent tube with toluene or any other suitable organic solvent. The extract is analyzed by GC (using a NPD or FPD) or by GC/MS. The column conditions and the characteristic ions for compound identifications are presented in the preceding section. Desorption efficiency of the solvent should be determined before the analysis by spiking a known amount of the analyte into the sorbent tube or filter and then measuring the spike recovery. 

Several qualitative and quantitative immunochemical methods and their application to the analysis of environmental samples have been described for OP insecticides, a family that includes widely used pesticides such as azinphos-ethyl/methyl, dichlorvos, fenitrothion or fenthion, malathion, mevinphos, and parathion. Mercader and Montoya202 produced monoclonal antibodies against azinphos-methyl and developed an ELISA that was used for the analysis of water samples from different sources, reaching detectability levels near 0.05 pg I. Watanabe et al.203 reported the production of polyclonal antibodies and ELISA procedures to analyze fenitrothion in river, tap, and mineral water (LOD = 0.3 pg L ). Banks et al.204 produced polyclonal antibodies against dichlorvos, an organophosphate insecticide used for stored grain, which also cross-reacts with fenitrothion. Nishi et al.205 reported the first immunoassay for malathion. Residues of this insecticide have... 

The technique was used to determine several organophosphorus pesticides (E)- and (Z)-Mevinphos, Dichlorvos, Azinphos-methyl, Azinphosethyl, Parathion-methyl, Parathion-ethyl, Malathion, Fenitrothion, Fenthion, Chlorfenvinphos and Diazinon, in groundwater. 

Pesticides include such a diversity of chemical types that it is not surprising that their toxicity covers a very wide range. For example, as little as 100 mg of mevinphos or of nicotine may cause death, whereas... 

The 22 following OPPs and metabolites are on the U.S. National Pesticide Survey list diazinon, dichlorvos, dicrotophos, dimethoate, diphenamiphos sulfone, disulfoton, disulfoton sulfone, disulfoton sulfoxide, fenamiphos, fenamiphos sulfone, fenamiphos sulfoxide, fenitrothion, methyl paraoxon, mevinphos, monocrotophos, omethoate, parathion ethyl, phosphamidon, stirofos, terbufos, tetrachlorvinphos, and merphos. 

Organophosphorus pesticides Acephate , Azinphos-methyl , Chlorpyrifos , Chlorpyriphos-methyl , Diazinon , Dichlorvos (DDVP), Dicrotophos , Dimethoate , Disulfoton , Ethoprop , Eenamiphos , Eenitrothion , Fenthion , Fosthiazate , Malathion , Methamidophos , Methidathion , Methyl-parathion , Mevinphos , Naled , Oxydemeton-methyl , Para-thion , Phorate , Phosalone , Phosmet , Pirimiphos-methyl , Profenofos , Terbufos , Tetrachlorvinphos , Trichlorfon . 

Nicotine (Black Leaf 40) Chemical Profile 4/85. Pesticide Man agement Education Program, Cornell University. http //pmep.cce.cornell.edu/profiles/insect mite/ mevinphos propargite/nicotine/insect prof nicotine.html (accessed on October 20, 2005). 

The blood enzymes appear to act as buffers for the enzymes in the tissue. There is little inhibition of tissue enzyme until much of the blood enzyme is inhibited. The RBC-ChE appears to be more important than the plasma enzyme in this regard. In two studies,35,36 a small dose of DFP in humans inhibited about 90% of the plasma enzyme activity but only 15% to 20% of RBC-ChE activity. Symptoms correlated with depression of RBC-ChE, but not with depression of BuChE (see the Central Nervous System and Behavior section below). In humans, some pesticides, such as parathion,79 systox,37 and malathion,20 also preferentially inhibit the plasma enzyme, while others, such as dimefox39 and mevinphos,40 initially bind with the RBC enzyme. In animals, there appears to be a species difference, inasmuch as parathion preferentially inhibits RBC-ChE in rats and the plasma enzyme in dogs.20... 

Monomethyl metaphosphate (methyl phosphenate) Me0P02 (13.147b) and the PO3 anion (13.147a) are formed by electron impact and can be observed in the mass spectra of pesticides such as Monocrotophos and Mevinphos, (Me0)2P(0)0C(Me)=CH C(0)0Me (Table 12.29). 

FIGURE 2.2 UHPLC-MS of pesticide residues spiked in tea (0.1 mg/kg) obtained with an Aquity UPLC BEH Shield C18 (2.1 x 150 mm, 1.7 pm) (Waters) and a QqQ mass analyser (Quattro Micro API) working in MRM mode. The compounds separated are (1) Propamocarb (2) Primicarb (3) Carbofuran-3-hydroxy (4) Mevinphos (5) Acetamiprid (6) Thiofanox-sulphon (7) Spiroxamine (8) Triasulfuron (9) Bromoxynil (10) Promecarb (11) Triadimefon (12) Fenhexamid (13) Fenoxycarb (14) Clethodim 15 Flufenoxuron. (Adapted from Chen, G., Cao, P, and Liu, R. 2011. Food Chem. 125 1406-1411. With permission.)... 

Jung H-D, Ramsauer E (1987) Akute Pesticid-Intoxication kombiniert mit epikucaner Sensibilierung durch den organ-ischen Phosphorsaureester Mevinphos (PD-5). Aktuel Dermatol 13 82-83... 

Azinphos-ethyl, carbophenothion, diazinon, ethion, malathion, mevinphos, parathion, and OP pesticides were determined in fruits and vegetables by beef liver esterases and S-bromoindoxy 1 acetate. Their TLC separation was carried out on silica gel plates developed in acetone-hexane (1 4) (163). 

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