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Monthly Newsletter
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The Importance of Organoselenium Speciation
 The toxicity and bioavailability of selenium is dictated by the molecular form, concentration, and the capacity of an organism to metabolize the selenium in a useful manner or detoxify it. There are many parts of the world that have selenium deficiencies which necessitate augmentation of the diet with viable sources of selenium, particularly cattle feed, which is typically in the form of selenized yeast. In other circumstances, selenium is introduced in excess to the environment causing mutations and mortality in fish and birds. In both of these cases, the importance of knowing more than just the total selenium concentration is of paramount importance.
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Some of our clients have questioned why so many separate bottles are needed for similar analyses, when it would be so much easier for their sample collection team to collect one bottle to be split by the lab upon receipt. For example, if a client wants to measure total and dissolved total mercury (THg) and methylmercury (MeHg), we would send out four fluoropolymer or glass bottles, one for each analysis. Is this overkill? Well, according the conclusions drawn from
a recent paper co-authored by BAL's VP of Operations,
Annie Carter, it is not.
The lead author on this paper, titled
Assessing bias in total mercury results after removing a subsample from the bottle, is former Brooks Rand Labs employee, Dr. Joel Creswell, who now works at the EPA. The research presented in the paper demonstrates that removing a subsample from the original bottle prior to addition of bromine monochloride (BrCl) can result in a positive bias for the THg concentration measured from the original container. The proposed mechanism for the bias is that 'excess' inorganic Hg is adsorbed to the bottle walls and is not accounted for in the subsampled aliquot. The adsorbed inorganic Hg is then drawn into solution when BrCl is added. Collecting THg and MeHg samples in separate bottles whenever possible is recommended by the study authors. This same bias mechanism would apply if a subsample was removed from the original bottle to be filtered for dissolved Hg; therefore, collecting total and dissolved THg samples in separate bottles whenever possible is always advised by BAL scientists. Your BAL technical and project management team is ready to provide you with critical information like this prior to your next sampling event.
Contact us today!
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BAL at SETAC and International Water Conference
 That's right, Brooks Applied Lab staffers are making appearances at conferences all over the country next month! The week of November 6
th - 10
th
Elizabeth Madonick and
Tiffany Stilwater will be attending the Society of Environmental Toxicology and Chemistry (
SETAC) World Congress and North American Annual Meeting in sunny Orlando, Florida! This is the first year that our
newly merged lab will be exhibiting at the SETAC Conference, and Elizabeth will be presenting the research of
Jacki Aitken, a metals chemist and group leader in BAL's Metals Speciation Group. Keep an eye out for Jacki's poster on the
Maternal transfer of metals in Steller Sea Lions (Eumetopias jubatus) from the Washington State Coast. Meanwhile
Russ Gerads and
Jamie Fox will be in San Antonio, Texas the same week to attend
The International Water Conference. This conference focuses on the technical aspects of treatment, use, and reuse of water for industrial and engineering purposes. Please feel free to reach out to any of our staff if you or your colleagues are planning to attend either conference!
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Meaningful Metals Data and Advanced Speciation Solutions
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Small Business Enterprise
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