Detection and Quantification of Ricin in Beverages Using Isotope Dilution Tandem Mass Spectrometry
The toxic plant protein ricin has gained notoriety due to wide availability and potential use as a bioterrorism agent, with particular concern for food supply contamination. We have developed a sensitive and selective mass spectrometry-based method to detect ricin in tap water, 2% milk, apple juice,...
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Published in | Analytical chemistry (Washington) Vol. 83; no. 8; pp. 2897 - 2905 |
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Main Authors | , , , , |
Format | Journal Article |
Language | English |
Published |
Washington, DC
American Chemical Society
15.04.2011
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Subjects | |
Online Access | Get full text |
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Summary: | The toxic plant protein ricin has gained notoriety due to wide availability and potential use as a bioterrorism agent, with particular concern for food supply contamination. We have developed a sensitive and selective mass spectrometry-based method to detect ricin in tap water, 2% milk, apple juice, and orange juice. Ricin added to beverage matrices was extracted using antibody-bound magnetic beads and digested with trypsin. Absolute quantification was performed using isotope dilution mass spectrometry with a linear ion trap operating in product-ion-monitoring mode. The method allows for identification of ricin A chain and B chain and for distinction of ricin from ricin agglutinin within a single analytical run. Ricin-bound beads were also tested for deadenylase activity by incubation with a synthetic ssDNA oligomer. Depurination of the substrate by ricin was confirmed by matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOFMS). This method was used successfully to extract ricin from each beverage matrix. The activity of recovered ricin was assessed, and quantification was achieved, with a limit of detection of 10 fmol/mL (0.64 ng/mL). |
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ISSN: | 0003-2700 1520-6882 |
DOI: | 10.1021/ac102571f |