Soil-sorbed atrazine

Park J-H, Feng Y, Ji P, Voice TC, Boyd SA (2003) Assessment of bioavailability of soil-sorbed atrazine. Appl Environ Microbiol 69 3288-3298 Pignatello JP, Sawhney BL, Frink CR (1987) EBD persistence in soil. Science 236 898... 

Jones, T.W. and PS. Estes. 1984. Uptake and phytotoxicity of soil-sorbed atrazine for the submerged aquatic plant, Potamogeton perfoliatus L. Arch. Environ. Contam. Toxicol. 13 237-241. 

In addition to SOM, clay minerals are another important component that may influence contaminant-soil interactions. Expandable 2 1 type clays are usually more reactive than other clay minerals. Park et al. (2003) used a K-saturated montmorillonite as a sorbent to evaluate the availability of sorbed atrazine to three atrazine-degrading bacteria. K-saturated montmorillonite has a high atrazine sorption capacity with a Freundlich sorption... 

Of the various inorganic soil constituents, smectites (montmorillonite clays) have the greatest potential for sorption of pesticides on account of their large surface area and abundance in soils. Weak base pesticides, both protonated and neutral species, have been shown to be sorbed as interlayer complexes. Sorption of atrazine on smectites ranges from 0 to 100% of added atrazine, depending on the surface charge density of the smectite (36). 

The amount of a triazine retained or sorbed by soil can range from 0% to 100% of the amount applied, but typically sorption on silt loam, loam, or clay loam surface soils ranges from 50% to 80% of the amount applied. Although sorption of triazines (particularly atrazine) by soils has been studied for more than 40 years, there continue to be numerous studies each year to quantify sorption by different soils and to characterize the factors that affect triazine sorption. For instance, in a review of literature for 1964-1984, Koskinen and Moorman (1985) found 343 published Kd values for sorption of atrazine on 148 soils. These published Kd values averaged 4.0 4.0. From 1985 through 1995, 35 additional references reported Kd or Kf values for atrazine alone (Table 21.6). Average reported Kd values are 2.4 7.3 for 109 surface and subsurface soils (Paya-Perez et al., 1992) and 4.9 1.9 for 117 surface soils (Jaynes et al., 1995). 

In this procedure, the interferences are removed by SPE and the analytes pass through the sorbent. An example is the isolation of nonionic herbicides from soil, atrazine and alachlor. Because soil is commonly extracted with methanol or acetonitrile, there is a substantial amount of humic material extracted at the same time. Both methanol and acetonitrile are miscible with water and readily penetrate the pores and surfaces of soil organic matter, which is hydroscopic and contains sorbed water. Because soil organic matter is attached to silicate surfaces and iron and aluminum hydroxides, it readily binds water to its... 

Sites contaminated by chlorinated pesticides (e.g. dichlorodiphenyltrichloroethane (DDT), aldrin, dieldrin, and endrin) and herbicides (e.g. atrazine, molinate and bentazone) due to agricultural activities and accidental spills have received little attention (Chapters 11 and 12). These contaminants are nonpolar in characteristics and sorb strongly to the soil. Similar to other hydrophobic organic compounds, desorption using solubilizing agents such as surfactants and cosolvents as well as... 

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