title: Depth distribution of sulfonamide antibiotics in pore water of an undisturbed loamy grassland soil.
abstract: Despite the concern raised by the detections of veterinary antibiotics like sulfonamides (SA) in the environment, their fate in soils is still not sufficiently understood. In a previous article, we demonstrated that manure may substantially influence losses of SA via runoff from soils. Here, we report on the effect of manure on SA availability in soil pore water. Three sulfonamides (sulfadimidine, sulfadiazine, sulfathiazole) and two tracers (bromide and Brilliant Blue) were either applied in manure or as aqueous solution on grassland plots. After 1 and 3 d contact time, the plots were irrigated with deionized water. One day after irrigation, soil cores were taken and profiles of pore water concentrations were determined. The median SA concentrations of the top layer on manured plots varied between 40 and 60 microg L(-1) and between 10 and 30 microg L(-1) on the controls. For the conservative tracer Br the mass recovery was about 60 to 75% and much lower for the SA (2 to 14%). Apparent distribution coefficients K(d,app) of the SA in the topsoil ranged between 3 and 15 L kg(-1) on the manured plots and between 30 to 35 kg L(-1) on the controls. Below the top layer, the concentration distribution showed a pattern typical for preferential flow. Locally, SA concentrations down to 30- to 50-cm depth were as high as in the top 5 cm with little effect of the two application matrices. In the topmost layer, the data indicate that 10 to 25% of sulfadimidine were transformed to its acetyl-metabolite.
authors.affiliation: Department of Urban Water Management, Swiss Federal Institute for Aquatic Science and Technology (Eawag), Uberlandstrasse 133, 8600 Dübendorf, Switzerland.
authors.forename: Michael
authors.initials: M
authors.lastname: Burkhardt
authors.forename: Christian
authors.initials: C
authors.lastname: Stamm
mesh_terms: D000327:Adsorption; D000818:Animals; D000900:Anti-Bacterial Agents / Q000032:analysis* / Q000737:chemistry; D001965:Bromides / Q000032:analysis; D008372:Manure / Q000032:analysis; D006109:Poaceae; D016062:Porosity; D012987:Soil; D012989:Soil Pollutants / Q000032:analysis* / Q000737:chemistry; D013449:Sulfonamides / Q000032:analysis* / Q000737:chemistry; D013552:Swine; D014867:Water / Q000032:analysis
chemical_list: D000900:Anti-Bacterial Agents; D001965:Bromides; D008372:Manure; D012987:Soil; D012989:Soil Pollutants; D013449:Sulfonamides; D014867:Water