87764-37-2Relevant articles and documents
Elimination of racemic and enantioenriched metalaxyl based fungicides under tropical conditions in the field
Monkiedje, Adolphe,Zuehlke, Sebastian,Maniepi, Saurelle Jacqueline Ngouopiho,Spiteller, Michael
, p. 655 - 663 (2007)
The elimination has been studied of racemic and enantioenriched metalaxyl applied as an emulsifiable concentrate and wettable powder combined with copper in a Cameroonian field site. The kinetics of the degradation/dissipation of metalaxyl and its acid metabolite were investigated using reversed phase HPLC-MS/MS, while the enantiomeric ratios were measured by HPLC-MS/MS using a Chiralcel OD-H HPLC column. Some soil enzymes activities were determined concurrently for 120 d. The elimination of racemic metalaxyl was shown to be enantioselective, with the R-enantiomer being degraded more slowly than the S-enantiomer. Dissipation followed approximate square root first-order kinetics (R > 0.98) without lag phases. The enantiomers of metalaxyl have different elimination rates, with half-lives ranging from only 0.8 to 1.5 days. After application to soil, the elimination of metalaxyl in the copper containing formulation was slower. The activities of acid phosphatase, alkaline phosphatase, and alkaline glucosidase were monitored throughout the experiments. No significant influence of metalaxyl and copper could be observed on these parameters. The significantly shorter half-life values of all forms of metalaxyl under field conditions, compared to the previously reported laboratory derived ones, may have implications for the plant disease control with these fungicides in tropical rainforest areas.
Persistence, fate, and metabolism of [14C]metalaxyl in typical Indian soils
Sukul, Premasis,Spiteller, Michael
, p. 2352 - 2358 (2001)
The biodegradation of ring-labeled [14C]metalaxyl in six Indian soils was examined. The total recovery of radioactivity from soil was 100 ± 6% of the applied radioactivity. Volatile organics and 14CO2 were detected at lower levels. This suggests that neither mineralization nor volatilization is a major route of metalaxyl dissipation. The most rapid degradation of metalaxyl was observed in Bannimantap soil, in which the half-life of metalaxyl was 36 days. An inverse relationship was found when half-lives were plotted against microbial biomass and soil clay content. However, soil total organic carbon did not correlate with metalaxyl persistence. Five metabolites detected by thin-layer chromatography were more polar than metalaxyl.
