Citation:

HEITHMAR, E. M., G. MOMPLAISIR, AND C. G. ROSAL. COMPLEMENTARY APPROACHES TO THE DETERMINATION OF ARSENIC SPECIES RELEVANT TO CONCENTRATED ANIMAL FEEDING OPERATIONS. Presented at National Environmental Monitoring Conference, Cambridge, MA, August 20, 2007.

Impact/Purpose:

Provide state-of-the-science sampling, analysis, separation, and detection methods to allow rapid, accurate field and laboratory analyses of contaminated soils, sediments, biota, and groundwater to support Superfund clean-up decisions. Apply state-of-the-science methods in chemical analysis and data interpretation (e.g., mass spectral interpretation) to actual problems of OSWER, the Regions, and the States, in cooperation with the Las Vegas Technical Support Center as well as by direct contacts with Regional and State employees. Provide technical advice and guidance to OSWER using the environmental chemistry expertise (e.g., mass spectrometry, analytical methods development, clean-up methodology, inorganics, organometallics, volatile organics, non-volatile organics, semi-volatile organics, separation technologies, etc.) found within the branch.

Technical research support for various projects initiated either by Regions/Program Offices or ECB scientists. While these efforts will support the Regions and Program Offices, they cannot be predicted or planned in advance, and may serve multiple duty (e.g., solve real-world problems, serve to ground-truth analytical approaches that ECB is developing, transfer new technology). Many of the activities in this task support requests involving enforcement decisions and therefore are categorized as "environmental forensics".

Description:

Ion-exchange chromatography is the most often used analytical approach for arsenic

speciation, due to the weak-acid nature of several of its species. However, no single

technique can determine all potentially occurring arsenic species, especially in complex

environmental matrices. Solid and liquid waste streams from concentrated animal

feeding operations (CAFOs) are particularly challenging, due to the likely presence of

certain phenylarsonic acid derivatives and their transformation products. This laboratory

has employed inductively coupled plasma mass spectrometry with both reverse-phase

high performance liquid chromatography and capillary electrophoresis to determine

several arsenic species relevant to CAFOs. We have focused on roxarsone (4-hydroxy-

3-nitrophenylarsonic acid) and its potential transformation products, including

phenylarsonic acid derivatives, as well as arsenate, arsenite, and pentavalent dimethyl and

monomethyl arsenic acids. Gas chromatography/mass spectrometry with on-line vacuum

distillation has been applied to determine volatile arsenic species. We will present a brief

discussion of the issue of organoarsenicals in CAFO waste, a description of the three

analytical approaches, some example results from waste extracts, and finally a discussion

of the strengths and limitations of the approaches.

Record Details: