Author/Editor     Šinigoj-Gačnik, K
Title     Analitika polietrskih antibiotikov (salinomicina, monensina, lasalocida) v kokošjih jajcih
Translated title     Analysis of polyether antibiotics (salinomycin, monensin, lasalocid) in eggs
Type     članek
Source     Slov Vet Res
Vol. and No.     Letnik 38, št. 2
Publication year     2001
Volume     str. 147-56
Language     slo
Abstract     A modified method for simultaneous determination of polyether antibiotics (salinomycin, monensin, lasalocid) in eggs is described. After the tissue had been homogenized in acetonitrile, the extract was partitioned between saturated salt and carbon tetrachloride and the organic layer evaporated to dryness. Clean-up was done by solid-phase extraction on a silica column. One half of the final solution in n-hexane was evaporated and redissolved in methanol-water for the analysis of lasalocide by HPLC. A reversed phase column (C-18) was used with an acidic mobile phase and fluorescence detection with excitation at 310 nm and emission at 420 nm. The other half of the final solution in n-hexane was spotted onto silicagel plates and developed in suitable solvent system (ethyl acetate-water), for the analysis of salinomycin and monensin by high-performance thin-layer chromatography with chemical detection using p-anisaldehyde as a derivative reagent. The intensity of coloured spots was measured by densitometry at 510 nm. The limits of detection and of quantification for lasalocid in eggs were 20 and 25 ng/g respectively, and for both salinomycin and monensin 10 and 20 ng/g respectively. The average recovery of lasalocid from eggs at 25 to 100 ng/g levels was 49.6 % (RSD = 14.7 %), for salinomycin at the same levels 87.8 % (RSD = 13.3 %) and for monensin at 20 to 100 ng/g levels 89.9 % (RSD = 19.6 %).
Summary     Opisali smo modificirano metodo istočasnega določanja ostankov polietrskih antibiotikov salinomicina, monensina in lasalocida v kokošjih jajcih. Vzorce jajc smo najprej homogenizirali z acetonitrilom, nakar smo z ekstrakcijo tekoče-tekoče čistili izvlečke z nasičeno raztopino soli in jih ekstrahirali v tetraklorometan, čemur je sledila uparitev organskega topila. Čiščenje smo nadaljevali na silicijevih kolonah. Polovico končne raztopine v n-heksanu smo uparili, ponovno raztopili v metanolvodi in jo uporabili za določanje lasalocida s tekočinsko kromatografijo. V ta namen smo uporabili kolono C-18 z mešanico metanola in kislega pufra kot mobilne faze in z meritvami fluorescence pri ekscitaciji 300 nm in emisiji 420 nm. Drugo n-heksansko polovico končne raztopine smo nanesli na silikagelske plošče in jih razvijali v primernem razvijalcu (etilacetat-voda) za določanje salinomicina in monensina s tankoplastno kromatografijo visoke zmogljivosti s kemijsko vizualizacijo s p-anisaldehidom. Intenziteto obarvanih madežev smo merili z denzitometrom pri 510 nm. Meji zaznavnosti in meji vrednotenja metode za lasalocid sta bili 20 in 25 ng/g, za salinomicin in monensin pa 10 in 20 ng/g. Izkoristek metode za lasalocid je bil 49,6 % (RSD = 14,7 %) v območju od 25 do 100 ng/g lasalocida v jajcih. Izkoristek za salinomicin v istem območju je znašal 87,8 % (RSD = 13,3 %), za monensin pa 89,9 % (RSD = 19,6 %) v območju od 20 do 100 ng/g.
Descriptors     POULTRY
EGGS
FOOD ANALYSIS
DRUG RESIDUES
MONENSIN
LASALOCID
CHROMATOGRAPHY, THIN LAYER
CHROMATOGRAPHY, LIQUID