Adsorption of Chlorantraniliprole: Which Soil Factors Affect Sorbent Affinity?.

Structural termite damage and control costs average $5 billion USD yr-1 in the United States, which is in part due to labor-intensive control practices currently employed such as soil-injection or trenching.  Surface termiticide application on soil surrounding structures could offer a simpler, cost-efficient alternative to injecting/trenching.  Previous research has shown downward soil distribution of the termiticide, chlorantraniliprole, can be improved via increasing application carrier volume and the use of soil surfactants; however, results varied across soils of varying textures (clay or sand) and organic matter contents (low [1-2% w w-1] and moderate [3-5%]).  Laboratory research was initiated to determine the degree to which certain soil texture and organic matter concentration affect chlorantraniliprole-soil sorption.  Four soil textures (clay, clay loam, sand, or silt loam) were evaluated at two soil organic matter contents (native amount or native + 2.5% w w-1).  Chlorantraniprole was spiked at 0, 1, 2, 4, 8, or 12 mg kg-1, and the parent compound was quantified 24 h later using high performance liquid chromatograph-diode array detector-mass spectroscopy methodology to develop chlorantraniliprole-soil sorption isotherms.