This European Standard specifies a high performance liquid chromatography - mass spectrometry (LC-MS/MS) method for the identification of tylosin, spiramycin, virginiamycin, carbadox and olaquindox in animal feeds.
The method is suitable for the identification of low concentrations of tylosin, spiramycin, virginiamycin, carbadox and olaquindox in compound animal feeds. A limit of identification of 1 mg/kg for tylosin, spiramycin and virginiamycin, 4 mg/kg for carbadox and 3 mg/kg for olaquindox should be obtained by using the described method. The method was fully validated during a collaborative study (see Annex A).
Since tylosin, spiramycin and virginiamycin are fermentation products consisting of a mixture of several closely related compounds, the analysis is based on detection and identification of the most abundant constituents. For tylosin the marker is tylosin A, for spiramycin the marker is spiramycin I and II and for virginiamycin the marker is virginiamycin M1 and S1. The other isomers and forms can be readily detected with the same method but adjustment of the MS parameters according to the molecular mass of precursor and product ions need to be made. Carbadox and olaquindox are analysed as such.