title: Behaviour of mesotrione in maize and soil system and its influence on soil dehydrogenase activity.
abstract: The aim of this study was to investigate the dissipation of mesotrione and effect on dehydrogenase activity (DHA) in maize and soil system. The paper for the first time describes behaviour of this herbicide applied at various doses (separately or in mixture with other herbicide) in acidic and alkaline environment. The experiments were conducted using the method randomized blocks in four repetition cycles. Chemical application in seven variants at recommended doses of herbicide were performed. The sample preparation was performed by a modified QuEChERS method and the concentrations of mesotrione in maize and soil were determined by the liquid chromatography with tandem mass spectrometry (LC-MS/MS). The limit of detection was 0.0005mgkg(-1) and quantification 0.001mgkg(-1). The dissipation of mesotrione were described according to first-order (FO) kinetics equation with R(2) were between 0.8794 and 0.9934. The initial deposit of herbicide in soil and maize was higher in an acidic environment (0.06-0.18mgkg(-1)). A positive correlation between an alkaline pH and the rate of dissipation in soil was observed. The results showed that the time after which 50% (DT50) of substance has been degraded was different for both plant and soil. DT50 for soil was within the range 3.2-6.0days and 2.9-4.4days, for the maize 3.9-4.8days and 3.4-4.5days in an alkaline and an acidic environment, respectively. Concentration of mesotrione at applicable MRL level of 0.05mgkg(-1) in maize was achieved at 0.5-5.9days and at proposed MRL of 0.01mgkg(-1) at 8.8-15.8days. The results indicate that the application of mesotrione affected on DHA in the soil. One day after application this herbicide, concentration of DHA in soil was lower than in control plots, but after 21days was observed trend of increasing DHA.
authors: Plant Protection Institute - National Research Institute, Laboratory of Pesticide Residues, Chelmonskiego 22, Bialystok, Poland. Electronic address: P.Kaczynski@iorpib.poznan.pl.
authors: Piotr
authors: P
authors: Kaczynski
authors: Plant Protection Institute - National Research Institute, Laboratory of Pesticide Residues, Chelmonskiego 22, Bialystok, Poland.
authors: Bozena
authors: B
authors: Lozowicka
authors: Plant Protection Institute - National Research Institute, Laboratory of Pesticide Residues, Chelmonskiego 22, Bialystok, Poland.
authors: Izabela
authors: I
authors: Hrynko
authors: Bialystok University of Technology, Faculty of Civil and Environmental Engineering, Wiejska 45 E, Bialystok, Poland.
authors: Elzbieta
authors: E
authors: Wolejko
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D002853:Chromatography, Liquid; D003512:Cyclohexanones / Q000737:chemistry*; D006540:Herbicides / Q000737:chemistry*; D007700:Kinetics; D010088:Oxidoreductases / Q000235:genetics* / Q000378:metabolism; D012987:Soil / Q000737:chemistry*; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000737:chemistry*; D053719:Tandem Mass Spectrometry; D003313:Zea mays / Q000378:metabolism / Q000382:microbiology
chemical_list: D001426:Bacterial Proteins; D003512:Cyclohexanones; D006540:Herbicides; D012987:Soil; D012989:Soil Pollutants; C432907:mesotrione; D010088:Oxidoreductases
keywords: Dehydrogenase; Dissipation; Maize; Mesotrione; Soil