title: Acute toxicity of the dissociating veterinary antibiotics trimethoprim to Willow trees at varying pH.
abstract: The willow tree acute toxicity test was applied to determine the acute toxicity of the neutral and the ionic form of the antibiotic trimethoprim (TMP) to trees. The pKa of the weak base TMP is at 7.2, and the toxicity testing was done at low (pH 4.3), medium (pH 6.4) and high pH (pH 8.15). The test gave toxic effects, i.e. reduced transpiration at an external concentration of 100 mg/L TMP at medium and high pH, where the neutral form of TMP dominates. At an external concentration of 1,000 mg/L, also at low pH an effect occurred, but it was less pronounced than at medium pH.
authors.affiliation: Masaryk University, Faculty of Science, Research Centre for Toxic Compounds in the Environment, RECETOX, Kamenice 126, Brno, Czech Republic.
authors.forename: Ondrej
authors.initials: O
authors.lastname: Mikes
authors.forename: Stefan
authors.initials: S
authors.lastname: Trapp
mesh_terms: D000900:Anti-Bacterial Agents / Q000633:toxicity*; D006863:Hydrogen-Ion Concentration; D018526:Plant Transpiration / Q000187:drug effects; D032108:Salix / Q000187:drug effects*; D012989:Soil Pollutants / Q000633:toxicity; D023382:Toxicity Tests, Acute; D014295:Trimethoprim / Q000633:toxicity*; D019155:Veterinary Drugs / Q000633:toxicity*
chemical_list: D000900:Anti-Bacterial Agents; D012989:Soil Pollutants; D019155:Veterinary Drugs; D014295:Trimethoprim