DETERMINATION OF MONENSIN, SALINOMYCIN AND NARASIN IN MUSCLE, LIVER AND EGGS FROM DOMESTIC-FOWL USING LIQUID-CHROMATOGRAPHY ELECTROSPRAY MASS-SPECTROMETRY

A method is presented for the simultaneous determination of the three ionophores, monensin, salinomycin and narasin in muscle, liver and egg s from domestic fowl. Samples are homogenised in methanol and any iono phores present are extracted into toluene-hexane. The extracts are con centrated and injected into a bench-top electrospray LC-MS system. Chr omatography is carried out using an end-capped reversed-phase column, with a mobile phase consisting a mixture of acetonitrile, methanol, te trahydrofuran, trifluoroacetic acid and water. Using single-ion monito ring, the ionophores can be detected down to the 1 ng/g level.