Metabolism of 14C-labelled and non-labelled sulfadiazine after administration to pigs.
The behaviour of sulfadiazine (SDZ) and its metabolites was investigated by administering the (14)C-labelled veterinary drug to fattening pigs. The excretion kinetics were determined after daily collection of manure. Two known metabolites, N-acetylsulfadiazine and 4-hydroxysulfadiazine, and two hitherto unidentified minor metabolites were recovered. Various mass spectrometric techniques such as parent, product ion scans and accurate mass measurement were used. The new compounds were identified as N-formylsulfadiazine (For-SDZ) and N-acetyl-4-hydroxysulfadiazine (Ac-4-OH-SDZ). The identification of SDZ, Ac-SDZ and For-SDZ was confirmed by comparison of the spectroscopic and chromatographic data of the synthesized authentic references. The identification of the hydroxylated compounds 4-OH-SDZ and Ac-4-OH-SDZ was performed by MSn, and accurate mass measurements. Only 4% of the administered radioactivity remained in the pig after ten days and SDZ accounted for 44% of the 96% radioactivity excreted. More than 93% of the labelled compounds were detected and identified in the manure. The key analytical problem, namely a high concentration of matrix in sample extracts, was overcome by advanced measurement techniques and with the use of a suitable internal standard. The mean recoveries for all compounds were >or=96%. Linearity was established over a concentration range of 0.5 to 10,000 microg kg(-1) manure with a correlation coefficient>or=0.99. The same experiment was carried out simultaneously with non-labelled SDZ to obtain manure for outdoor soil experiments.
Lamshöft
Marc
M
Institute of Environmental Research (INFU), University of Dortmund, Otto-Hahn-Strasse 6, 44221, Dortmund, Germany.
Sukul
Premasis
P
Zühlke
Sebastian
S
Spiteller
Michael
M
D000818:Animals; D002247:Carbon Isotopes; D002851:Chromatography, High Pressure Liquid; D006900:Hydroxylation; D007700:Kinetics; D008372:Manure; D008660:Metabolism; D013411:Sulfadiazine / Q000008:administration & dosage / Q000378:metabolism*; D013552:Swine; D053719:Tandem Mass Spectrometry
D002247:Carbon Isotopes; D008372:Manure; D013411:Sulfadiazine