The aim of the study is to suggest the method of ricin determination in biological liquids during forensic medical and chemicotox-icological examination. This research describes the optimal conditions of sample processing of biological liquids, allowing to ex-tract the components (ricinine and ricinoleic acid) of castor seeds. The recommended analysis conditions allow to perform research for 15 minutes by high resolution mass spectrometry method combined with high-value liquid chromatography on a chroma-to-mass spectrometer to detect ricinine and ricinoleic acid. The chromatographic (retention time) and mass-spectrometric param-eters (mass spectra) were established for the exact high-quality determination of ricinine and ricinoleic acid. © 2023, Media Sphera Publishing Group. All rights reserved.