Determination Of Six Membered Ring Sulfonamides used In Veterinary Medicine In Manure, Soil And Soil leachates Using Lc-esi Mass Spectrometry

摘要

Sulfonamides are one of the most prescribed groups of veterinary antibiotics in the European Union and most of these substances are six-membered ring sulfonamides. Sulfonamides occur in liquid manure, soils and soil interstitial water due to excretion with and land application of contaminated manure. Hence, trace level analysis of contaminations by sulfonamides in several mixed soil-manure-water substrates is demanded. A simple extraction method for sulfanilamide, sulfadiazine, sulfapyridine, sulfadimidine, and sulfadimethoxine from soil, manure, and soil-manure mixtures with methanol, and from soil leachates with solid phase cartridges, is proposed yielding a mean recovery rate of 72% in all these matrices. Additionally, a fast, selective and sensitive method was tailored for the trace-level determination of the sulfonamides by LC-ESI-MS/MS. Adjusting the offset voltage and, especially the ion source capillary temperature individually for each sulphonamide, improved the sensitivity of the MS/MS. Combined with the use of matrix-matched external standards for quantification, this resulted in limits of determination ≤1.1 μg mL~(-1). The analytical procedure was applied to contaminated samples. Experiments with manure that was separated in its liquid and solid phase showed that a considerable fraction (13-91 % of the applied amount) of sulfonamides remained in the liquid phase. Results from field experiments indicated a high leaching potential of sulfonamides to ground-water by exceeding the limit values, though the total amount of leached sulfonamide was low.