title: Slow-release formulations of the herbicide MCPA by using clay-protein composites.
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.
authors.affiliation: Department of Science, University of Basilicata, Potenza, Italy.
authors.forename: Alaa Aldin
authors.initials: AA
authors.lastname: Alromeed
authors.affiliation: Department of European Culture (DICEM), University of Basilicata, Matera, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Scrano
authors.affiliation: Department of Science, University of Basilicata, Potenza, Italy.
authors.forename: Sabino A
authors.initials: SA
authors.lastname: Bufo
authors.affiliation: Institute of Natural Resources and Agrobiology (IRNAS-CSIC), Seville, Spain.
authors.forename: Tomás
authors.initials: T
authors.lastname: Undabeytia
mesh_terms: D008456:2-Methyl-4-chlorophenoxyacetic Acid / Q000737:chemistry*; D001546:Bentonite; D005780:Gelatin; D006540:Herbicides / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D012987:Soil / Q000737:chemistry
chemical_list: D006540:Herbicides; D012987:Soil; D001546:Bentonite; D005780:Gelatin; D008456:2-Methyl-4-chlorophenoxyacetic Acid
keywords: MCPA; clay; herbicide formulations; protein; slow release; soil