New analytical techniques for mycotoxins in complex organic matrices

dc.contributor.author Bicking, Merlin
dc.contributor.department Chemistry
dc.date 2018-08-16T12:15:49.000
dc.date.accessioned 2020-07-02T05:57:58Z
dc.date.available 2020-07-02T05:57:58Z
dc.date.copyright Fri Jan 01 00:00:00 UTC 1982
dc.date.issued 1982
dc.description.abstract <p>Air samples are collected for analysis from the Ames Solid Waste Recovery System. The high level of airborne fungi within the processing area is of concern due to the possible presence of toxic mycotoxins, and carcinogenic fungal metabolites. An analytical method has been developed to determine the concentration of aflatoxins B1, B2, G1, and G2 in the air of the plant which produces Refuse Derived Fuel (RDF);After extraction with methanol, some components in the matrix are precipitated by dissolving the sample in 30% acetonitrile/chloroform. An aliquot of this solution is injected onto a Styragel column where the sample components undergo simultaneous size exclusion and reverse phase partitioning. Additional studies have provided a more thorough understanding of solvent related non-exclusion effects on size exclusion gels. The Styragel column appears to have a useable lifetime of more than six months. After elution from Styragel, the sample is diverted to a second column containing Florisil which has been modified with oxalic acid and deactivated with water;Aflatoxins are eluted with 5% water/acetone. After removal of this solvent, the sample is dissolved in 150 (mu)L of a spotting solvent and the entire sample applied to a thin layer chromatography (TLC) plate using a unique sample applicator developed here. The aflatoxins on the TLC plate are analyzed by laser fluorescence;A detection limit of 10 pg is possible for aflatoxin standards using a nitrogen laser as the excitation source. Sample concentrations are determined by comparing with an internal standard, a specially synthesized aflatoxin derivative. In two separate RDF samples, aflatoxin B1 was found at levels of 6.5 and 17.0 ppb. The analytical method has also proven useful in the analysis of contaminated corn and peanut meal samples;In a separate study, the spore pigment in Aspergillus flavus wasisolated. The mass spectrum indicates a molecular weight in excessof 700. Only aliphatic hydrocarbons have been identified in the massspectrum of products from a permanganate oxidation. The isolatedpigment is obviously a mixture and no further work was done to;elucidate structures;('1)This research was supported by U.S. Department of Energy, Contract No. W-7405-Eng-82.</p>
dc.format.mimetype application/pdf
dc.identifier archive/lib.dr.iastate.edu/rtd/7027/
dc.identifier.articleid 8026
dc.identifier.contextkey 6304180
dc.identifier.doi https://doi.org/10.31274/rtd-180813-5174
dc.identifier.s3bucket isulib-bepress-aws-west
dc.identifier.submissionpath rtd/7027
dc.identifier.uri https://dr.lib.iastate.edu/handle/20.500.12876/79859
dc.language.iso en
dc.source.bitstream archive/lib.dr.iastate.edu/rtd/7027/r_8221175.pdf|||Sat Jan 15 01:41:00 UTC 2022
dc.subject.disciplines Analytical Chemistry
dc.subject.keywords Chemistry
dc.subject.keywords Analytic
dc.subject.keywords Chemistry
dc.subject.keywords Chemistry (Organic - Analytical)
dc.subject.keywords Organic chemistry
dc.title New analytical techniques for mycotoxins in complex organic matrices
dc.type article
dc.type.genre dissertation
dspace.entity.type Publication
relation.isOrgUnitOfPublication 42864f6e-7a3d-4be3-8b5a-0ae3c3830a11
thesis.degree.level dissertation
thesis.degree.name Doctor of Philosophy
File
Original bundle
Now showing 1 - 1 of 1
No Thumbnail Available
Name:
r_8221175.pdf
Size:
2.22 MB
Format:
Adobe Portable Document Format
Description: