Fast and single method for quantitation of ricinine or L-abrine in plasma and urine by ultra-high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS)

L-abrine and ricinine are two small molecules found respectively in the seeds of Abrus precatorius and Ricinus communis. L-abrine and ricinine are extracted simultaneously with the toxins ricin and abrin from the seeds and are therefore exposure markers for these toxins. We developed and validated a fast and simple method for the simultaneous quantitation of ricinine and L-abrine in plasma and urine by ultra-high performance liquid chromatography coupled with a tandem mass spectrometer (UHPLC LC40 Nexera X3-TQ8060 Shimadzu). A pretreatment step was achieved using solid phase extraction on the Strata®-X 30 mg, 1 mL cartridge (Phenomenex) before a chromatographic separation on a Luna Omega Polar C18 column (50 × 2.1 mm, 1.6 μm; Phenomenex) with a gradient of mobile phase composed of water and acetonitrile, each containing 0.1% formic acid. This method is sensitive (lower limit of quantification at 0.4 and 2 ng/mL in plasma and in urine respectively), fast (chromatographic analysis in 5 minutes), easier and cheaper than the proteomic analysis of the toxins. It represents an interesting alternative for highlighting an intoxication by ricin or abrin.