A simple method for screening and quantification of ricinine in feed with HPLC and LC-MS

A simple high-performance liquid chromatography (HPLC) and liquid chromatography-mass spectrometry (LC-MS) method for screening and quantification of ricinine in feeds is established for use in feed quality control. Ricinine is extracted from the sample with methanol. The sample extract is directly used for screening with LC-MS and is cleaned up using solid-phase extraction for quantification with HPLC and LC-MS. A 9 min isocratic elution with 10% acetonitrile (v/v) at a flow rate of 0.2 mL/min is performed on an Atlantis dC(18) column (5 microm, 2.1 x 100 mm) at ambient temperature with UV detection at 310 nm and MS in positive selective ion recording mode. Good linearity (r(2) > or = 0.99) is found in the investigated concentration ranges from 0.054 to 55.4 microg/mL for HPLC and 5 to 1000 ng/mL for LC-MS. In the final extracts, the limits of detection (LOD) and quantification (LOQ) for HPLC are 75 pg and 150 pg, respectively; the LOD and LOQ for HPLC-MS are 6 pg and 15 pg, respectively.