Human plasma ricinine quantification by LC-HRMS after micro-solid-phase elution

A rapid, sensitive and specific method for ricinine identification and quantification in plasma has been developed by LC-HRMS. Deuterated ricinine was used as the internal standard. From 100 mu L of plasma, ricinine was extracted using micro-solid-phase elution, which allows a reduced extraction time, by eliminating the evaporation step. Eluate is directly injected into the LC-HRMS system. Chromatographic separation was performed using a reverse-phase C-18 column with a 4.5 min gradient elution. The method was validated according to European Medicines Agency guidelines. Linearity was verified between 0.25 and 500.0 ng/mL; the maximum precision calculated was 19.9% for the lower limit of quantitation and 9.6% for quality control, and accuracy was within +/- 5.6% of the nominal concentrations. Selectivity, carryover, matrix effect and stability were also verified according to European Medicines Agency guidelines. The method allows the rapid and reliable identification of ricin-exposed victims in case of terrorist attacks or poisonings: three intoxication cases are reported.

Automated summary

A rapid, sensitive and specific LC-HRMS method was developed for the identification and quantification of ricinine in plasma. Micro-solid-phase elution was used to extract ricinine from 100 μL of plasma, eliminating the evaporation step and reducing extraction time. The method was validated according to European Medicines Agency guidelines and showed good linearity, precision, and accuracy. The method allows rapid and reliable identification of ricin-exposed victims in cases of terrorist attacks or poisonings, as demonstrated by the report of three intoxication cases.