Premium
Reduced metribuzin pollution with phosphatidylcholine–clay formulations
Author(s) -
Undabeytia Tomás,
Recio Esther,
Maqueda Celia,
Morillo Esmeralda,
GómezPantoja Eulalia,
SánchezVerdejo Trinidad
Publication year - 2011
Publication title -
pest management science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.296
H-Index - 125
eISSN - 1526-4998
pISSN - 1526-498X
DOI - 10.1002/ps.2060
Subject(s) - metribuzin , chemistry , sorption , leaching (pedology) , montmorillonite , active ingredient , adsorption , environmental chemistry , bioavailability , alachlor , chromatography , soil water , chemical engineering , atrazine , pesticide , organic chemistry , soil science , environmental science , agronomy , bioinformatics , weed control , biology , engineering
BACKGROUND: Metribuzin is a widely used herbicide that has been identified as a groundwater contaminant. In this study, slow‐release formulations of metribuzin were designed by encapsulating the active ingredient in phosphatidylcholine (PC) vesicles and adsorbing the vesicles onto montmorillonite. RESULTS: The maximum active ingredient content in the slow‐release formulations was 246 g kg −1 . Infrared spectroscopy results revealed that the hydrophobic interactions between metribuzin and the alkyl chains on PC were necessary for encapsulation. In addition, water bridges connecting the herbicide and the PC headgroup enhanced the solubility of metribuzin in PC. Adsorption experiments in soils were performed to evaluate the relationship between sorption and leaching. Funnel experiments in a sandy soil revealed that the herbicide was not irreversibly retained in the formulation matrix. In soil column experiments, PC–clay formulations enhanced herbicide accumulation and biological activity in the top soil layer relative to a commercial formulation. PC–clay formulations also reduced the dissipation of metribuzin by a factor of 1.6–2.5. CONCLUSIONS: A reduction in the recommended dose of metribuzin can be achieved by employing PC–clay formulations, which reduces the environmental risk associated with herbicide applications. Moreover, PC and montmorillonite are non‐toxic and do not negatively affect the environment. Copyright © 2010 Society of Chemical Industry