title: Analysis of carbohydrate and fatty acid marker abundance in ricin toxin preparations for forensic information.
abstract: One challenge in the forensic analysis of ricin samples is determining the method and extent of sample preparation. Ricin purification from the source castor seeds is essentially a protein purification through removal of the nonprotein fractions of the seed. Two major, nonprotein constituents in the seed are the castor oil and carbohydrates. We used derivatization of carbohydrate and fatty acid markers followed by identification and quantification using gas chromatography/mass spectrometry (GC/MS) to assess compositional changes in ricin samples purified by different methods. The loss of ricinoleic acid indicated steps for oil removal had occurred, and a large decrease of ricinoleic acid was observed between unextracted mash and solvent extracted and protein precipitate preparations. Changes to the carbohydrate content of the sample were also observed following protein precipitation. The differential loss of arabinose relative to mannose was observed indicating the removal of the major carbohydrate fraction of the seed and enrichment of the protein content. When the data is combined and multivariate principle component analysis is applied, these changes in fatty acid and carbohydrate abundance are discriminating enough to be indicative of the preparation method used for each sample.
authors.affiliation: Chemical and Biological Signature Sciences, National Security Directorate, Pacific Northwest National Laboratory, P.O. Box 999, MSIN P7-50, Richland, Washington 99352, USA. Heather.Colburn@pnl.gov
authors.forename: Heather A
authors.initials: HA
authors.lastname: Colburn
authors.forename: David S
authors.initials: DS
authors.lastname: Wunschel
authors.forename: Helen W
authors.initials: HW
authors.lastname: Kreuzer
authors.forename: James J
authors.initials: JJ
authors.lastname: Moran
authors.forename: Kathryn C
authors.initials: KC
authors.lastname: Antolick
authors.forename: Angela M
authors.initials: AM
authors.lastname: Melville
mesh_terms: D001089:Arabinose / Q000737:chemistry; D002241:Carbohydrates / Q000032:analysis*; D002619:Chemical Warfare Agents / Q000737:chemistry*; D005227:Fatty Acids / Q000032:analysis*; D053593:Forensic Toxicology; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D025341:Principal Component Analysis; D012276:Ricin / Q000737:chemistry*; D012277:Ricinoleic Acids / Q000737:chemistry
chemical_list: D002241:Carbohydrates; D002619:Chemical Warfare Agents; D005227:Fatty Acids; D012277:Ricinoleic Acids; D012276:Ricin; D001089:Arabinose; C030521:ricinoleic acid