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Characterization of Selenium in Solids

Brooks Applied Labs has developed a proprietary method for characterizing the molecular forms of selenium in soil, sediment, industrial byproducts, and biosolids. The technology we have generated allows our clients to ascertain the fate and transport of selenium in the solid phase environment as well as to identify the efficacy of treatment systems. The molecular form of selenium will dictate the toxicity, mobility through a solid substrate, treatability, bioavailability, and bioaccessibility. Our method currently supports discrete quantitation of selenite, selenate, selenocyanate, and methylseleninic acid, as well as fractionation of reduced selenium complexes (e.g., Cd-Se, Hg-Se, and Pb-Se), elemental selenium, and non-extractable selenium compounds.

Traditionally, characterization of metals and metalloid compounds in solid substrates has been limited to generic selective sequential extraction approaches (SSE), scanning electron microscopy energy dispersive spectrometry (SEM-EDS), or synchrotron based approaches (XAFS and XANES). These analytical approaches have limitations that increase the probability of generating inaccurate data, data of limited use necessitating gross assumptions, or misidentification of molecules.

The information generated from our customized selective sequential extraction (SSE) approach is presented in the table below. Unlike most SSE approaches, the first two fractions allow for speciation analyses via ion chromatography inductively coupled plasma mass spectrometry (IC-ICP-MS) for discrete molecular identification and quantification. Fractions 3 and 4 target insoluble selenium species which have specific reactivity in accordance with the chemical bonds. The final fraction allows for mass balance in comparison to the total selenium concentration.

Fraction Description of Target Selenium Species
Fraction 1 Highly mobile ions (SeO4-2, MeSe(IV), SeCN)
Fraction 2 Adsorbed ions (SeO4-2, SeO3-2, SeCN, MeSe(IV))
Fraction 3 S2Se, Se0 (amorphous and crystalline)
Fraction 4 Selenides (HgSe, PbSe, CdSe, ZnSe)
Fraction 5 Non-extractable Selenium

Our proprietary method has been applied worldwide for over a decade to support selenium concerns. Our partners (clients) have been able to address problems with quantitative results instead of computer models and theories. At Brooks Applied Labs we continue to strive to generate novel preparatory and analytical approaches that meet or exceed the needs of the marketplace and the scientific community.

Brooks Applied Labs is On the Road Again…

International Mercury Conference
Last month, VP of Operations, Annie Carter, along with our Mercury Group Leader, David Westby, presented a poster at the International Conference on Mercury as a Global Pollutant (ICMGP) in Providence, RI. The title of the poster they presented is “An Alternative Analytical Technique for Mercury Speciation in Radioactive Tank Waste at the Savannah River Site” and it discussed novel techniques developed just for this unique matrix to compare measurements made by traditional methods to more selective and modern analytical approaches. Contact Us if you would like to learn more!

 

National Environmental Monitoring Conference (NEMC)

VP of Quality, Frank McFarland, will be chairing a session at NEMC in Washington, DC, which is taking place August 7 – 11. The title of the session is “Metals and Metals Speciation Analysis in Environmental Samples.” We know that all you fellow attendees will be sticking it out with Frank on the last morning of the conference and encourage you to stop by and say hello! It’s worth mentioning this session has been chaired by Brooks Applied Labs all but two years since 2010, and is naturally near and dear to our hearts to promote and advance good science surrounding metals analysis. Please support it with us!

5-Year Anniversaries at Brooks Applied Labs!

Brooks Applied Labs had three employees recently celebrate their 5-year anniversary with the company. Project Coordinator Jacki Aitken, Project Manager Jeremy Maute, and Quality Assurance Associate Coila Craig. BAL strives to maintain high levels of employee satisfaction and retention through consistent adherence to our Core Values, and we are grateful to these wonderful employees for their years of dedication and outstanding performance at our company. Congratulations Jacki, Jeremy, and Coila – and thank you so much for all that you do to make our company great!