Effects of dietary n-3 polyunsaturated fatty acids and ... - FINS

1 st WorkshopXIII International Feed Technology Symposiumexplains the smaller slower elution larger concentration of salinomycin applied to silicagel column, and is more efficient elution samples with high content of salinomycinapplication required greater volume of methanol.Table 1. Results of the determination of contents of salinomycin in premixes and broilerfeed by spectrophotometric methodAdded[µg/g feed]Found ± SD[µg/g feed]Efficacy of extraction(% ) ± SD10 10,4±0,7 103,5±6,820 18,6±0,5 92,8±5,430 26,9±0,9 89,5±8,640 34,3±0,8 85,7±7,560 50,3±0,7 83,8±5,4Based on the results we can conclude that our original extraction method is suitable toextract salinomycine from premixes and poultry feed samples., and that thespectrophotometric method can be successfully applied in monitoring the content ofsalinomycin in eluates, with detection limit of 0,5 mg/kg poultry feed. This means thatthe described method allows the determination of 120 times lower concentrations ofpreventive doses of salinomycine in broiler feed, which is 60 mg/kg feed.For the quantitative determination of salinomycin content in the poultry feed samplescomparative method was elaborated liquid chromatography with post-columnderivatisation with vanillin reagent. Salinomycin from samples extracted by columnchromatographyand eluated with methanol. Eluents was centrifuged and filtered.Separation was carried out with TSK ODS-120T, 10µm column with a mobile phaseconsisting of methanol- water – acetic acid (94:6:0,1, v/v/v) and than using post-columnderivatisation with vanillin reagent. Detection was performed with a spectrophotometricdetector with tungsten lamp at 520 nm. Retention time for salinomycine, under theseconditions of the determination, is 12,0 min. Results of the determination of contents ofsalinomycin in premixes and broiler feed by high performance liquid chromatographyare shown in table 2. Based on the results shown in table 2, we notice that the applicationof the described HPLC procedure is possible to determine the salinomyin content in thepoultry feed samples with high reproducibility rates, ranging from 96,3±2,6 % to112,7±2,7% and detection limit of 15 µg/kg of examined poultry feed.279