Table 4: Samples from the Finnish national feed control programme from 2008 analysed by LC-MS/MS.

Monensin (mg/kg)Narasin (mg/kg)

Feed 10.046<0.025
Feed 20.73<0.025
Feed 3<0.0250.26
Feed 40.0590.47
Feed 5<0.0250.12
Feed 60.0801.6
Feed 70.0360.26
Feed 80.0550.17

Lasalocid, maduramicin, and semduramicin were not detected with LC-MS/MS. All samples analysed with HPLC-UV were negative. Lasalocid, maduramicin, and semduramicin were not measured with HPLC-UV.