Simulating sulfadimidine transport in surface runoff and soil at the microplot and field scale.

To prevent residues of veterinary medicinal products (VMPs) from contaminating surface waters and ground water, an environmental impact assessment is required before a new product is allowed on the market. Physically based simulation models are advocated for the calculation of predicted environmental concentrations at higher tiers of the assessment process. However, the validation status of potentially useful models is poor for VMP transport.

Dissipation and transport of veterinary sulfonamide antibiotics after manure application to grassland in a small catchment.

The heavy use of veterinary antibiotics in modern animal production causes concern about risks of spreading antibiotic resistance after manure applications to agricultural fields. We report on a field study aiming at elucidating the fate of sulfonamide (SA) antibiotics in grassland soils and their transport to surface water. Two controlled manure applications were carried out under different weather conditions.

Exhaustive extraction of sulfonamide antibiotics from aged agricultural soils using pressurized liquid extraction.

A pressurized liquid extraction (PLE) method was developed for the quantification of five sulfonamide antibiotics (sulfadiazine, sulfadimethoxine, sulfamethazine, sulfamethoxazole, and sulfathiazole) in aged soil samples. To account for sequestration effects the extraction was optimized using a composite grassland soil sample collected 11 days after the application of manure containing these substances. The optimized method uses a mixture of buffered water (pH 8.

Tetracyclines and tetracycline resistance in agricultural soils: microcosm and field studies.

The influence of the use of antibiotics on the prevalence of resistance genes in the environment is still poorly understood. We studied the diversity of tetracycline and sulfonamide resistance genes as influenced by fertilization with pig manure in soil microcosms and at two field locations. Manure contained a high diversity of resistance genes, regardless of whether it stemmed from a farm operation with low or regular use of antibiotics.

Fully automated online solid phase extraction coupled directly to liquid chromatography-tandem mass spectrometry. Quantification of sulfonamide antibiotics, neutral and acidic pesticides at low concentrations in surface waters.

A fully automated online solid phase extraction-liquid chromatography-tandem mass spectrometry (SPE-LC-MS/MS) instrumental setup has been developed for the quantification of sulfonamide antibiotics and pesticides in natural water. The direct coupling of an online solid phase extraction cartridge (Oasis HLB) to LC-MS/MS was accomplished using column switching techniques. High sensitivity in the low ng/L range was achieved by large volume injections of 18 mL with a combination of a tri-directional auto-sampler and a dispenser system.