Quantitative Analysis of L-Abrine and Ricinine Spiked into Selected Food Matrices by Liquid Chromatography-Tandem Mass Spectrometry

Abstract

Abrin and ricin are highly toxic and lethal proteins which have the potential to be used as bioterrorism agents.Labrine and ricinine, molecular biomarkers for abrin and ricin, serve as useful biomarkers in assessing exposure and contamination.In this study, we developed a method for the quantitation of L-abrine and ricinine spiked into four food types: ground beef, chicken breast, hot dogs, and Eggbeaters®.This method involved sample homogenization, followed by polymeric reversed solid phase extraction, evaporation, and reconstitution.Determination and quantitation of L-abrine and ricinine was achieved using LC tandem mass spectrometry utilizing positive electrospray ionization. Quantitation was based upon fragmentation of m/z219→132 for L-abrine and m/z 165→138 for ricinine.The limit of detection achieved was 0.1 µg/L while the limit of quantitation was 0.50 µg/L for L-abrine and 0.30 µg/L for ricinine.A 7-point standard calibration curve showed good linearity for both analytes (r2 = 0.990) with a CV of <10% for replicates.Spiked fortified food matrices at 5 µg/L, 25 µg/L, and 50 µg/L yielded recoveries ranging from 93-119%. Validation results showed this method to be rapid, accurate, sensitive, and suitable for surveillance monitoring of food products suspected of abrin and ricin contamination.