Determination of tetracycline residues in eggs using LC-MS/MS and UHPLC/Q-TOF-MS methods

Upotreba antibiotika kao veterinarskih lijekova može dovesti do pojave njihovih rezidua u hrani životinjskog podrijetla kao što su meso goveda, svinja i peradi, mlijeko i mliječni proizvodi, jaja, ribe i med. Zahvaljujući širokom spektru djelovanja prema Gram-pozitivnim i Gram-negativnim bakterijama, rikecijama, mikoplazmama, klamidijama i jednostaničnim parazitima, tetraciklinski antibiotici su našli široku primjenu u veterinarskoj medicini. Rezidui antibiotika mogu imati nepovoljne učinke na zdravlje potrošača, a jedna od posljedica pretjerane uporabe antibiotika je i širenje antibiotičke rezistencije. Stoga je nužno razviti učinkovite metode za određivanje rezidua tetraciklinskih antibiotika u hrani životinjskog podrijetla kako bi se spriječilo daljnje širenje antibiotičke rezistencije. U ovom je radu provedena optimizacija tekućinske kromatografije s tandemskom spektrometrijom masa (LC-MS/MS) i tekućinske kromatografije ultravisoke djelotvornosti sa spektrometrijom masa i analizatorom vremena preleta (UHPLC/Q-TOF-MS), u svrhu postizanja maksimalne osjetljivosti i selektivnosti instrumenata za određivanje rezidua tetraciklina, epitetraciklina, oksitetraciklina, epioksitetraciklina, klortetraciklina, epiklortetraciklina, i doksiciklina, u obogaćenim uzorcima jaja, pri čemu je veća osjetljivost postignuta UHPLC/Q-TOF-MS metodom. Usporedbom rezultata određivanja rezidua tetraciklinskih antibiotika u uzorcima jaja pokazalo se da su obje primjenjene metode ekstrakcije analita, otapalom i Quechers ekstrakcijom, uspješno provedene, pri čemu je Quechers ekstrakcijom, primjenom LC-MS/MS metode, postignuta bolja ponovljivost, nego kod uzoraka dobivenih ekstrakcijom organskim otapalom.The usage of antibiotics as veterinary drugs can lead to apperance of residues in foods of animal origin, including meat from bovine and porcine animals and poultry, milk and dairy products, eggs, fish and honey. Due to broad spectrum of activity against Gram-positive and Gram-negative bacteria, rickettsiae, mycoplasmas, chlamydiae and protosoan parasites, tetracyclines are wildely used in veterinary medicine. Antibiotic residues can have negative effects on health of consumer who was in contact with contaminated food, and one consequence of excessive usage of antibiotics is antibiotic resistance. Therefore, it is necessery to develop effective methods for determination residues of tetracyclines in animal-derived foods, in order to prevent further spread of antibiotic resistance. In this paper optimization of liquid chromatography with tandem mass spectrometry (LC-MS/MS) and ultra-high performance liquid chromatography coupled with hybrid quadrupole time-of-flight mass spectrometry (UHPLC/Q-TOF-MS) methods was carried out in order to achieve maximum instrument sensitivity and selectivity for determining residues of tetracycline, epitetracycline, oxytetracycline, epioxytetracycline, chlortetracycline, epichlortetracycline and doxycycline, in enriched egg samples, where UHPLC/Q-TOF-MS method had shown higher sensitivity. Both extraction methods, Quechers extraction and organic solvent extraction, were shown to be efficient. However, compared to samples obtained with organic solvent extraction, samples obtained with Quechers extraction, using LC-MS/MS method, achieved better repeatability