Trace Level Determination of Polyether Ionophores in Feed

Table 4

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

	Monensin (mg/kg)	Narasin (mg/kg)
Feed 1	0.046	<0.025
Feed 2	0.73	<0.025
Feed 3	<0.025	0.26
Feed 4	0.059	0.47
Feed 5	<0.025	0.12
Feed 6	0.080	1.6
Feed 7	0.036	0.26
Feed 8	0.055	0.17

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.