Metalaxyl

Metalation Metalations Metalaxyl [137414-52-9] Metal borides Metal carbonyls... 

A solvent free, fast and environmentally friendly near infrared-based methodology was developed for the determination and quality control of 11 pesticides in commercially available formulations. This methodology was based on the direct measurement of the diffuse reflectance spectra of solid samples inside glass vials and a multivariate calibration model to determine the active principle concentration in agrochemicals. The proposed PLS model was made using 11 known commercial and 22 doped samples (11 under and 11 over dosed) for calibration and 22 different formulations as the validation set. For Buprofezin, Chlorsulfuron, Cyromazine, Daminozide, Diuron and Iprodione determination, the information in the spectral range between 1618 and 2630 nm of the reflectance spectra was employed. On the other hand, for Bensulfuron, Fenoxycarb, Metalaxyl, Procymidone and Tricyclazole determination, the first order derivative spectra in the range between 1618 and 2630 nm was used. In both cases, a linear remove correction was applied. Mean accuracy errors between 0.5 and 3.1% were obtained for the validation set. 

Buser H-R, MD Muller, ME Balmer (2002) Environmental behavionr of the chiral acetamide pesticide metalaxyl enantioselective degradation and chiral stability in soil. Environ Sci Technol 36 221-226. 

The need to develop and use chiral chromatographic techniques to resolve racemates in pesticide residues will be driven by new hazard and risk assessments undertaken using data from differential metabolism studies. The molecular structures of many pesticides incorporate chiral centers and, in some cases, the activity differs between enantiomers. Consequently, in recent years manufacturers have introduced resolved enantiomers to provide pesticides of higher activity per unit mass applied. For example, the fungicide metalaxyl is a racemic mix of R- and 5-enantiomers, both having the same mode of action but differing considerably in effectiveness. The -enantiomer is the most effective and is marketed as a separate product metalaxyl-M. In future, it will not be satisfactory to rely on hazard/risk assessments based on data from metabolism studies of racemic mixes. The metabolism studies will need to be undertaken on one, or more, of the resolved enantiomers. 

Sample Added/ mg kg Furaloxyl Found/ mg kg Recovery % Added/ mg kg Metalaxyl Found/ mg kg Recovery %... 

Fig. 9.73 Gas chromatograms of (1) standard containing 6ng of metalaxyl (B) (b) extract from soil Anot treated with metalaxyl and (c) extract of soil Aafter addition of metalaxyl at 20mg kg-1 (6 jl of 1g per 20ml). Column temperature 190°C. Detector temperature 250°C. Attenuation 50x1. 

Fig. 16.2 Cumulative probability distributions of Metalaxyl residue at 150, 300 and 500cm soil depths, simulated on the basis of Western Australian coastal sandy soil conditions. The diagram shows that the cumulative probabilities are high for Metalaxyl to reach the three soil depths at significant residue fractions (% applied)...

Metalaxyl acid, see Metalaxvl Methacrolein, see 2-Methyl-l,3-bntadiene Methacrylic acid, see Methyl methacrylate... 

CASRN 57837-19-1 molecular formula C15H21NO4 FW 279.30 Soil. Little information is available on the degradation of metalaxyl in soil however, Sharom and Edgington (1986) reported metalaxyl acid as a possible metabolite. Repeated applications of metalaxyl decrease its persistence. Following an initial application, the average half-life was 28 d. After repeated applications, the half-life decreased to 14 d (Bailey and Coffey, 1985). 

Andon, R.J.E., Counsell, J.F., Tees, E.B., Martin, J.F., and Mash, MJ. Thermodynamic properties of organic oxygen compounds. Part 17. Tow-temperature heat capacity and entropy of the cresols, Trans. Faraday Soc., 63 1115-1121,1967. Andon, R.J.E., Cox, J.D., and Herington, E.F.G. Phase relationships in the pyridine series. Part V. The thermodynamic properties of dilute solutions of pyridine bases in water at 25 °C and 40 °C, J. Chem. Soc. (London), pp. 3188-3196, 1954. Andrades, M.S., Sanchez-Martin, M.J., and Sanchez-Camazano, M. Significance of soil properties in the adsorption and mobility of the fungicide metalaxyl in vineyard soils, J. Agric. Food Chem., 49(5) 2363-2369, 2001. 

Bailey, A.M. and Coffey, M.D. Biodegradation of metalaxyl in avocado soils, Phytopathology, 75 135-137, 1985. 

Businelli, M., Patumi, M., and Marncchini, C. Identification and determination of some metalaxyl degradation prodncts in lettuce and sunflower, J. Agric. Food Chem., 32(3) 644-647,1984. 

Carsel, R.F., Nixon, W.B., and Ballantine, L.G. Comparison of pesticide root zone model predictions with observed concentrations for the tobacco pesticide metalaxyl in unsaturated zone soils. Environ. Toxicol Chem., 5(4) 345-353,1986. 

Owen, W.J. and Donzel, B. Oxidative degradation of chlortoluron, propiconazole, and metalaxyl in suspension cultures of various crop plants, Pestic. Biochem. Physiol, 26 75-89, 1986. 

Sharom, M.S. and Edgington, L.V. The adsorption, mobility, and persistence of metalaxyl in soil and aqueous systems. Can. J. Plant Pathol, 4 334-340, 1982. 

Sukop, M. and Cogger, C.G. Adsorption of carbofuran, metalaxyl, and simazine K c evaluation and relation to soil transport. J. Environ. Sci. Health, B27(5) 565-590, 1992. 

Topalov, A. Molnar-Gabor, D. Csnadi, J. Photocatalytic oxidation of the fungicide Metalaxyl dissolved in water over Ti02. Wat. Res. 1999, 33, 1372. 

Enantioselective Biodegradation of Metalaxyl by Sewage Sludge and Screening Bacteria... 

The acylalanines are characterised by metalaxyl, the most studied member of the group. Metalaxyl exists as two enantiomers, metalaxyl M being the most active. Metalaxyl is known to interact with the RNA polymerase-I-template complex,8 inhibiting the incorporation of ribonucleotide triphosphates into ribosomal RNA. 

Mazzola, M., Andrews, P.K., Reganold, J.P. and Levesque, C.A. 2002. Frequency, virulence, and metalaxyl sensitivity of Pythium spp. isolated from apple roots under conventional and organic production systems. Plant Disease 86 669-675. 

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