Chlorpyrifos methyl

The sfe of chlorpyrifos methyl from wheat followed by on-line Ic/gc/ecd has been investigated (93). Extraction profiles were generated to determine the maximum analyte recovery and the minimum extraction time. Using pure CO2, a 65% recovery of chlorpyrifos methyl spiked onto wheat at 50 ppb was reported. When 2% methanol was added to the CO2, the recovery from a one gram sample averaged 97.8% (n = 10, 4.0% RSD). 

Buck, N.A., B.J. Estesen, and G.W. Ware. 1980. Dislodgable insecticide residues on cotton foliage fenvalerate, permethrin, sulprofos, chlorpyrifos, methyl parathion, EPN, oxamyl, and profenofos. Bull. Environ. Contam. Toxicol. 24 283-288. 

Leuck, D.B., Jones, R.L., and Bowman, M.C. Chlorpyrifos-methyl insecticide residues their analysis and persistence in coastal bermuda grass and forage corn, J. Econ. Entomol, 69 287-290, 1975. 

Reagents, (a) Pesticide standards of acephate, bromopropylate, chlorpyrifos, chlorpyrifos-methyl, chlorothalonil, diazinon, dichlorvos, endosulfan I, endosulfan II, endosulfan sulfate, lindane, methamidophos, phosalone, procymidone, pyrazophos, triazophos, and vinclozoline (purity >98%) were supplied by Riedel de Haen (Seelze, Germany). For each pesticide, a stock standard solution (about 500 mg/L) was prepared in acetone. Spiking standard solution, containing 50 mg/L of each pesticide, was prepared in acetone from the stock standard solutions. 

Smolen, J. M., and A. T. Stone, Metal(hydr)oxide surface catalyzed hydrolysis of chlorpyrifos-methyl, chlorpyrifos-methyl oxon, and paraoxon , Soil Sci. Am. J., 62, 636-643 (1997b). 

R Serrano, FJ Lopez, A Roig-Navarro, F Hernandez. Automated sample clean-up and fractionation of chlorpyrifos, chlorpyrifos-methyl and metabolites in mussels using normal-phase liquid chromatography. J Chromatogr A 778 151-160, 1997. 

Extraordinary selectivity has been accomplished with the parathion-type of insecticide by incorporating Q or CH3 groups in the meta position of the aryl ring. These groups interact sterically with acetylcholinesterase (AChE), increasing the affinity for the insect enzyme and decreasing it with the mammalian enzyme. Selectivity also is enhanced by differences in the rates of microsomal oxidation of P=S to P=0 and in hydrolytic detoxication between insects and mammals. The compounds, fenitrothion, fenthion, ronnel, bromophos, iodofenfos, chlorpyrifos—methyl, and pirimiphos —methyl, and dicapthon are used widely in public health, household, and agricultural pest control. 

The first six organophosphorus and chlorinated organophosphorus pesticides dominate wheat-based products. Exhibit 7 shows that virtually all wheat-based products are, at a minimum, contaminated with malathion and chlorpyrifos-methyl. These data also suggest that although corn-based products can contain malathion and chlorpyrifos-methyl, they are much less likely to be contaminated by the first six organophosphorus and chlorinated organophosphorus pesticides. 

Generally, the chemical control is done in the spring time to coincide with the emerging of nymphs from winter sites using mineral oil or calcium polysulfur. Chlorpyrifos, chlorpyrifos-methyl, imidacloprid, methomyl, buprofezin, and dimethoate can be used as alternatives. 

S. cerevisiae can produce H2S and SO2 in the presence of sulfur-containing insecticides such as chlorpyrifos-methyl, fenitrothion, and methidathion (Cabras et al., 1995b Eschenbruch, 1974). These insecticides did not affect fermentative activity. Quinoxyfen, belonging to the family of quinolines, showed no effect on the alcoholic fermentation using three strains of yeasts (Cabras et al., 2000 Lopez et al., 2004). 

M. Del Carlo, M. Mascini, A. Pepe, D. Compagnone and M. Mascini, Electrochemical bioassay for the investigation of chlorpyrifos-methyl in vine samples, J. Agric. Food Chern., 50 (2002) 7206-7210. 

Amperometric activity of the electrodes in thiocholine before and following exposure to solutions of pesticides was measured. Sample to sample reproducibility was found to be favourable (RSD 6.6%), as was stability with electrodes being shown to be capable of being stored for up to 2 months at —18°C. Linear detection of chlorpyrifos methyl oxon by inhibition was obtained between 1 x 10 8 and 5 x 10 8M by this approach. 

A recent application of a tetracianoquinodimethane (TCNQ)-modi-fied SPE for the development of a biosensing device for chlorpyrifos methyl was also reported. This method was demonstrated to detect the active molecule both in standard solution and in commercial products (Reldan 22) with comparable sensitivity. The analytical protocol was then applied to grapes and vine leaf samples in order to improve safety in wine-making process [27]. 

Chlorpyrifos-methyl, methoprene Grain — Enzyme immunoassay — [141]... 

Chlorpyrifos-methyl. Two applications six days apart of 0.007 kg chlorpyrifos-raethyl/ha to a forest block had no noticeable effect on breeding songbird populations and induced only limited drift increases of aquatic invertebrates without significantly altering benthos populations or native fish diets (32). Applications of 0.72-0.86 kg chlorpyrifos-methyl/ha to streams caused severe disturbances of aquatic invertebrates and substantial depressions of benthos populations for several months (33). Diets of native fish were significantly altered due to effects on fish food organisms. Some mortality of crayfish and minnows was observed, but no brook trout mortality occurred. Chlorpyrifos-methyl has not been developed for forestry use in Canada. 

Common Name Chlorpyrifos-methyl Synonym Reldan... 

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