title: Residue analysis of tetracyclines and their metabolites in eggs and in the environment by HPLC coupled with a microbiological assay and tandem mass spectrometry.
abstract: Tetracyclines are widely used in farm animals. This can cause drug residues in products of animal origin and, after excretion of these substances, in animal slurry and in soil fertilized with that slurry. In this paper, we present a method based on a microbiological assay coupled with HPLC for the detection of oxytetracycline, tetracycline, and chlortetracycline in eggs. After a simple liquid extraction of the samples and HPLC separation, fractions were collected on microtiter plates, and the tetracyclines were analyzed using the Staphylococcus aureus assay. This method was able to identify residues of tetracyclines in eggs at a level set by regulatory agencies (i.e., 200 microg/kg). In addition, it was shown that the described microbiological method can be used as a screening assay for the detection of tetracyclines and possible biologically active metabolites in animal slurry and soil samples. Employing the same extraction procedure, it was demonstrated that LC-MS-MS allowed the quantification of 20-400 microg/kg in eggs with recoveries ranging from 71 to 109% and RSDs of 3-15%.
authors.affiliation: Department of Food Toxicology, School of Veterinary Medicine, Bischofsholer Damm 15, D-30173 Hannover, Germany.
authors.forename: Silke
authors.initials: S
authors.lastname: Sczesny
authors.forename: Heinz
authors.initials: H
authors.lastname: Nau
authors.forename: Gerd
authors.initials: G
authors.lastname: Hamscher
mesh_terms: D000818:Animals; D001681:Biological Assay; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004350:Drug Residues / Q000032:analysis*; D004531:Eggs / Q000032:analysis*; D005243:Feces / Q000737:chemistry; D005308:Fertilizers / Q000032:analysis; D013058:Mass Spectrometry / Q000379:methods; D012987:Soil / Q000032:analysis*; D013211:Staphylococcus aureus / Q000187:drug effects / Q000254:growth & development; D013754:Tetracyclines / Q000032:analysis* / Q000378:metabolism
chemical_list: D005308:Fertilizers; D012987:Soil; D013754:Tetracyclines