20 research outputs found
Dietary Exposure to a Group of Naturally Produced Organohalogens (Halogenated Dimethyl Bipyrroles) via Consumption of Fish and Seafood
Monitoring of Fusarium Trichothecenes in Canadian Cereal Grain Shipments from 2010 to 2012
A method involving dry grinding, rotary sample dividing, and gas
chromatography–mass spectrometry was evaluated for the analysis
of eight Fusarium trichothecenes in
cereal grains. Processing of whole cereal grains by the method produced
representative test portions for the analysis of deoxynivalenol (DON).
Method validation data, as well as the successful participation in
various international proficiency tests, demonstrated the analytical
method produced accurate and precise results. The evaluated method
was used to monitor DON, 3- and 15-acetyldeoxynivalenol, nivalenol
(NIV), T-2 toxin, HT-2 toxin, diacetoxyscirpenol, and fusarenon-X
in shipments of Canadian wheat, durum, barley, corn, rye, and oats
transported between August 1, 2010, and July 31, 2012. DON was the
most frequently measured trichothecene, found in 231 of the 303 samples
at concentrations up to 2.34 mg/kg; NIV was the next most frequently
observed trichothecene, but its occurrence was limited to barley.
Concentrations of DON were significantly associated with wheat class
and grade. The median DON concentration in durum (0.09 mg/kg) was
lower than that for hard red spring (0.21 mg/kg). Lower grades of
wheat also contained higher median concentrations of DON than higher
grades, supporting the current use of <i>Fusarium</i> damaged
kernels as a grading factor to manage DON
Examination of the bioaccumulation of halogenated dimethyl bipyrroles in an Arctic marine food web using stable nitrogen isotope analysis
Concentrations of four possibly naturally produced organohalogens - 1,1′-dimethyl-3,3′,4-tribromo-4,5,5′-trichloro-2,2′- bipyrrole (DBP-Br3Cl3), 1,1′-dimethyl-3,3′,4,4′-tetrabromo-5,5′-dichloro-2, 2′-bipyrrole (DBP-Br4Cl2), 1,1′-dimethyl-3,3′,4,4′,5-pentabromo-5′-chloro-2, 2′-bipyrrole (DBP-Br5Cl) and 1,1′-dimethyl-3,3′,4,4′,5,5′-hexabromo-2,2′- bipyrrole (DBP-Br6) - were quantitated and the extent of their magnification through an entire Arctic marine food web [measured as integrated trophic magnification factors (TMFs)] were calculated. The food web consisted of three zooplankton species (Calanus hyperboreus, Mysis oculata, and Sagitta sp.), one fish species [Arctic cod (Boreogadus saida)], four seabird species [dovekie (Alle alle), black guillemot (Cepphus grylle), black-legged kittiwake (Rissa tridactyla), and glaucous gull (Larus hyperboreus)], and one marine mammal species [ringed seal (Phoca hispida)]. Trophic levels in the food web were calculated from ratios of stable isotopes of nitrogen (15N/14N). All halogenated dimethyl bipyrrole (HDBP) congeners were found to significantly (P \u3c0.02) biomagnify, or increase in concentration with trophic level in the invertebrate - fish - seabird food web. DBP-Br4Cl2 (TMF=14.6) was found to biomagnify to a greater extent than DBP-Br3Cl3 (TMF=5.2), DBP-Br5Cl (TMF=6.9), or DBP-Br6 (TMF=7.0), even though the Kow of DBP-Br4Cl2 was predicted to be lower than those of DBP-Br5Cl and DBP-Br6. None of the four HDBP congeners in ringed seals followed the general trend of increasing concentration with trophic level, which was possibly due to an ability of the seals to metabolize HDBPs. Crown Copyright © 2001 Published by Elsevier Science Ltd. All rights reserved
Using anthropogenic contaminants and stable isotopes to assess the feeding ecology of Greenland sharks
Organochlorine contaminants (OCs) are a large group of ubiquitous pollutants that have potential as tracers of ecological processes. To examine this utility, we measured OCs, stable isotopes of nitrogen (δ15N) and carbon (δ15C), and stomach contents in a large Arctic marine fish, the Greenland shark (Somniosus microcephalus), collected in the Davis Strait region to examine the feeding ecology of this little studied elasmobranch. Stable isotopes and OCs were also measured in the turbot (Reinhardtius hippoglossoides) and stable isotopes in the ringed seal (Phoca hispida) and harp seal (Pagophilus groenlandicus) to put the shark results in context. Values of δ15N suggest that the Greenland shark feeds at a similar trophic level as the turbot and ringed seal (about the fourth trophic level) and at a higher trophic level than harp seals, despite the presence of many turbot and a single ringed seal in the stomach contents of 14 sharks. Values of δ13C indicate that source of carbon in turbot and Greenland shark is of a more pelagic origin than in ringed and harp seals. High concentrations of biomagnifying OCs in the sharks compared with the turbot (concentration 10-100X lower) and ringed seals (3-10X lower) suggest that the sharks feed at a higher trophic level than implied by stable isotopes. High urea levels found in the tissues of sharks may influence δ15N values, resulting in an underestimate of shark trophic position, and requires additional study. The presence of a ringed seal in the stomach of one shark, relatively high levels of a contaminant metabolite (oxychlordane; slowly formed in fish) in some sharks, and high OC levels suggest that seals may be a common food item of some Greenland sharks. This study shows the utility of using OCs in ecological study and suggests caution when interpreting stable-isotope data as a single indicator of trophic position
Fate of Ergot Alkaloids during Laboratory Scale Durum Processing and Pasta Production
The fate of ergot alkaloids during the milling of durum and subsequent production and cooking of pasta was examined. Durum samples containing varying amounts of ergot sclerotia (0.01–0.1% by mass) were milled, and all milling product was analyzed for 10 ergot alkaloids using liquid chromatography with tandem mass spectrometry. Spaghetti was prepared from the semolina obtained during milling. Ergocristine, ergocristinine, and ergotamine were the predominant ergot alkaloids observed in the milling fractions and spaghetti. Approximately 84% of the total ergot alkaloid mass of the whole grain durum resided in the milling product fractions associated with the outer kernel layers (bran, shorts, feeds). No consistent loss of ergot alkaloids was observed during the production or cooking of spaghetti. However, changes in the ratio of R- to S-enantiomers occurred during the milling and cooking of spaghetti. Products containing bran, shorts, and feeds, as well as cooked spaghetti, contained a higher proportion of the less biologically active S-enantiomers. The results of this study emphasize the need to monitor R- and S-enantiomers, and to consider food and feed products, as opposed to whole grain, when assessing any exposure of consumers to ergot alkaloids
Occurrence of Ergot and Ergot Alkaloids in Western Canadian Wheat and Other Cereals
A new method was
developed to analyze 10 ergot alkaloids in cereal
grains. Analytes included both “ine” and “inine”
type ergot alkaloids. Validation of the method showed it performed
with good accuracy and precision and that minor enhancement due to
matrix effects was present during LC-MS/MS analysis, but was mitigated
by use of an internal standard. The method was used to survey durum
and wheat harvested in 2011, a year in which ergot infection was particularly
widespread in western Canada. A strong linear relationship between
the concentration of ergot alkaloids and the presence of ergot sclerotia
was observed. In addition, shipments of cereals from 2010–2012
were also monitored for ergot alkaloids. Concentrations of total ergot
alkaloids in shipments were lower than observed in harvest samples,
and averaged from 0.065 mg/kg in barley to 1.14 mg/kg in rye. In shipments,
the concentration of ergot alkaloids was significantly lower in wheat
of higher grades