Ricin analytical methods

Almost all Schedule 1 chemicals are soluble in the organic NMR solvents used in verification (see Section 3.1) and can be analyzed by NMR spectroscopy. Saxitoxin (1.A.7) and ricin (1.A.8) differ from the others. Both are derived from natural sources - the former is a paralytic shellfish poison and the latter, a glycoprotein toxin (40). Analytical methods (ROPs) have not been established for either chemical. NMR data... 

Analytical methods include immune methods (ELISA) and liquid chromatography/mass spectrometry (LC/MS). Gastric contents can be assayed and ricin can be detected in blood and body fluids by radioimmunoassay and LC/MS (Darby et al, 2001 Mouser et al, 2007). 

A ricin detection method has been developed that couples LC-MS/MS with an enzyme-linked immunosorbent assay (ELISA).The analyte target for MS detection is adenine, which is released from ricin during the assay. Adenine detection limits were achieved at 0.1 ng/mL or 1.56 pM in a 500-pL sample volume with this method. This LC-MS method may be chosen over other techniques because milk and drinking water are the intended real-world application for this protocol [77]. Another MS/MS technique detects tryptic peptide fragments from ricin produced by an immunoassay technique. This technique utilizes the inherent speed of MS analysis to confirm peptide identity. This technique is applied to the detection of ricin in food and body fluids such as blood serum and saliva [78]. A similar LC-MS/MS method uses an organic solvent-assisted tryptic digest to prepare samples of crude ricin extracts. This sample preparation... 

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