Alaa Aldin Alromeed1, Laura Scrano2, Sabino A Bufo1, Tomás Undabeytia3. 1. Department of Science, University of Basilicata, Potenza, Italy. 2. Department of European Culture (DICEM), University of Basilicata, Matera, Italy. 3. Institute of Natural Resources and Agrobiology (IRNAS-CSIC), Seville, Spain.
Abstract
BACKGROUND: MCPA [(4-chloro-2-methylphenoxy) acetic acid] is a widely used herbicide showing high leaching in the soil. In this study, clay-protein-based formulations of this herbicide were designed to reduce the risk of water pollution resulting from conventional formulations. RESULTS: Clay-gelatin formulations of MCPA were prepared, and the influence of synthesis parameters such as pH and the presence of a plasticiser (glycerol) on the active substance content and performance of the new formulations was examined. Differential scanning calorimetry measurements provided information on the stability of the gelatin matrix in the gelatin-clay complex. Fourier transform infrared spectroscopy showed that the herbicide was retained by the formation of hydrogen bonds with side amino groups of the protein backbone and polyion complexation. Clay-protein-based formulations prepared at a pH below the isoelectric point value of the protein and in the absence of glycerol provided the slowest release of MCPA in water. Soil column experiments showed a fourfold reduction in leaching and improved bioactivity in the upper soil layer for the new formulation compared with a commercial product used as a control. CONCLUSIONS: A reduction in the recommended dose of MCPA can be achieved by employing clay-gelatin, which reduces the environmental risk associated with herbicide applications.
BACKGROUND:MCPA [(4-chloro-2-methylphenoxy) acetic acid] is a widely used herbicide showing high leaching in the soil. In this study, clay-protein-based formulations of this herbicide were designed to reduce the risk of water pollution resulting from conventional formulations. RESULTS: Clay-gelatin formulations of MCPA were prepared, and the influence of synthesis parameters such as pH and the presence of a plasticiser (glycerol) on the active substance content and performance of the new formulations was examined. Differential scanning calorimetry measurements provided information on the stability of the gelatin matrix in the gelatin-clay complex. Fourier transform infrared spectroscopy showed that the herbicide was retained by the formation of hydrogen bonds with side amino groups of the protein backbone and polyion complexation. Clay-protein-based formulations prepared at a pH below the isoelectric point value of the protein and in the absence of glycerol provided the slowest release of MCPA in water. Soil column experiments showed a fourfold reduction in leaching and improved bioactivity in the upper soil layer for the new formulation compared with a commercial product used as a control. CONCLUSIONS: A reduction in the recommended dose of MCPA can be achieved by employing clay-gelatin, which reduces the environmental risk associated with herbicide applications.
Authors: Jose L Marco-Brown; Tomás Undabeytia; Rosa M Torres Sánchez; María Dos Santos Afonso Journal: Environ Sci Pollut Res Int Date: 2017-03-09 Impact factor: 4.223
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