Quantification of Ricinine and Abrine in Human Plasma by HPLC–MS-MS: Biomarkers of Exposure to Ricin and Abrin

Abstract

Ricin and abrin are toxic ribosome-inactivating proteins found in plants. Exposure to these toxins can be detected using the biomarkers ricinine and abrine, which are present in the same plant sources as the toxins. The concentration of the biomarkers in urine and blood will be dependent upon the purification of abrin or ricin, the route of exposure, and the length of time between exposure and sample collection. Here, we present the first diagnostic assay for the simultaneous quantification of both ricinine and abrine in blood matrices. Furthermore, this is the first-ever method for the detection of abrine in blood products. Samples were processed by isotope-dilution, solid-phase extraction, protein precipitation and quantification by HPLC-MS-MS. This analytical method detects abrine from 5.00 to 500 ng/mL and ricinine from 0.300 to 300 ng/mL with coefficients of determination of 0.996 ± 0.003 and 0.998 ± 0.002 (n = 22), respectively. Quality control material accuracy was determined to have <10% relative error, and precision was within 19% relative standard deviation. The assay's time-to-first result is three hours including sample preparation. Furthermore, the method was applied for the quantification of ricinine in the blood of a patient who had intentionally ingested castor beans to demonstrate the test was fit-for-purpose. This assay was designed to support the diagnosis of ricin and abrin exposures in public health investigations.

Effect of Salicylic Acid in the Yield of Ricinine in Ricinus communis under Greenhouse Condition

“…In another investigation, Wang et al [ 30 ] reported R 2 values of 0.9992 and 0.9988 with HPLC and LC–MS, of the standard solution of ricinine with different standard concentrations (27.7, 13.8, 6.92, 3.46, 1.73, 0.87, 0.43, 0.22, 0.11, 0.05, and 0 µg mL −1 ) and (500, 250, 125, 62.5, 31.2, 15.6, 7.8, 3.9, 1.8 and 0 ng mL −1 ), respectively. Isenberg et al [ 31 ] determined the correlation of ricinine standard by HPLC, which showed a high linearity of R 2 = 0.996 with different ricinine standard concentrations (200, 20.0, 0.800, and 0 ng mL −1 ). In this research, a linearity of R 2 = 0.9618 was obtained with different ricinine standard concentrations (0, 6, 8, 16, 20 μg L −1 ); we proceeded to quantify the ricinine in the extracts.…”

Occurrence and Concentration of Chemical Additives in Consumer Products in Korea

“…The plant originated alkaloid is used as stabilizers, skin-conditioning agents, emulsion, and surfactants in cosmetics [36]. Due to its relatively high toxicity (LD50 value for mice is 2-3 µg/kg), the Organization for the Prohibition of Chemical Weapons listed ricinine as a schedule 1 toxic chemical [37].…”

Rapid, Sensitive and Reliable Ricin Identification in Serum Samples Using LC–MS/MS

“…To enable ricin identification, ricinine, a small alkaloid also found in castor bean seeds with higher levels compared to that of ricin, was suggested as a surrogate marker for ricin intoxication [ 10 ]. Indeed, the detection of ricinine in urine or serum was reported in an in vivo model for ricin intoxication [ 17 , 18 , 19 ] as measured in rat urine at least 48 h post exposure [ 18 ]. However, this approach may cause false positive results, due to the widespread use of ricinine-containing castor-oil in soaps, lubricants, dyes, pharmaceuticals, perfumes and food supplements.…”