Non-extractable pesticide residues in soils and plants

Abstract

Abstract

Application of [U-14C-phenyl]-cyprodinil on spring wheat to investigate the formation and structure of non-extractable residues within the cell wall

“…Xenobiotic fragments recycled into natural plant products are excluded from this definition, and are regarded as an integral indistinguishable part of the plant matrix [3,4]. Macromolecular components such as lignin, proteins, and polysaccharides (starch, cellulose, hemicellulose, pectin) serve as structures for the formation of bound or non-extractable residues [2,5,6,36,37].…”

Peer Reviewed: Nonextractable Pesticide Residues in Soil

“…Khan (16), Kearney (17 ), and Fuhr and Mittelstaedt (18) also proposed alternative definitions from time to time. Roberts's proposed definition, which was adopted by the International Union of Pure and Applied Chemistry, has evolved somewhat from the 1975 definition to this, stating that bound residues represent "chemical species originating from pesticides, used according to good agricultural practice, that are unextracted by methods which do not significantly change the chemical nature of these residues" (19). This definition is generally accepted in literature, although various experts proposed important modifications at a workshop in 1996 on bound residues in soil (20).…”

“Humification” Process or Formation of Refractory Soil Organic Matter

“…Non-extractable residues, (sometimes also referred to as bound residues, or non-extracted residues) in plants and soils are defined as chemical species originating from pesticides and herbicides (parent compounds, metabolites, and fragments) used in agriculture practice, that are unextractable by methods which do not significantly change the chemical nature of these residues. These non-extractable residues are considered to exclude fragments recycled through metabolic pathways leading to natural products (ROBERTS, 1984).The formation of bound residues can be analyzed by isotopic labels and in trace amounts only by the use of radiolabeled compounds. The radiotracer technique allows the transformation to be balanced and the residues formed to be quantified.…”

“…Nitro groups of anthropogenic chemicals are often reduced to amino groups before significant residue formation occurs. The amino derivative of certain pesticides contributes to relatively high amounts of residues and causes fast formation rates (ROBERTS, 1984). Reactions catalyzed by fungal ligninolytic exoenzymes were shown to generate oxidative cross-linking to typical humic structure moieties, which causes the formation of amide bonds DAWEL et al, 1997).…”