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ABI Research Summaries - Robyn Hannigan, Ph.D. Dr. Hannigan's research program is comprised of three strands each integrated under the conceptual theme of applied geochemistry:
These strands are conceptual units and represent thematic foci required for solving the overall problem of the nature of the metal chemistry in human (e.g., hair) and environmental (e.g., water, solid or gas) samples. The emphasis on each strand varies from time to time. Dr. Hannigan's research strategy is threefold: (i) set up large-scale goals; (ii) focus on individual, clearly-defined, short- to medium-term projects that fill in pieces of the larger-scale jigsaw puzzle; (iii) where possible projects should be interdisciplinary. Method Development for Metal Analysis in Environmental and Human Samples: Hannigan is developing new integrated instrumentation in collaboration with Dr. Jon Russ at ASU, PerkinElmer and Arnel, Inc. This instrumentation couples Dynamic Reaction Cell Inductively Coupled Plasma Mass Spectrometry (DRCII) with solid and gas sample introduction systems. Laser ablation (CETAC LSX500) allows the direct analysis of solid samples. In Hannigan's laboratory human hair samples are directly ablated and the metal composition of the hair characterized. This method of analysis is a vast improvement over traditional hair digestion and liquid introduction to the ICP-MS as the laser can be used to both clean the shaft of the hair as well as directly analyze the internal composition of the hair reducing contamination and proving better data for exposure monitoring. Coupling the DRCII to a specially engineering gas chromatograph (Clarus 500) equipped with sulfur, nitrogen and carbon detectors Hannigan and collaborators are developing a new analytical technique to quantify the metal concentrations in volatile samples. This research specifically focuses on the metal composition in volatile phases present in environmental tobacco smoke (ETS). Current metal measurements on ETS rely on particulate concentrations with no understanding of the metal composition in the gas phase. This analytical technique has far reaching consequences for environmental and health researchers. Assessment of Metal Pollution in Agricultural Regions: We use chemical data of rocks, soils, crops, groundwater and runoff to examine the transformation of metal species within agricultural areas. The specific focus is on natural contaminants such as selenium, mercury and arsenic and the rate of uptake and transformation by different crop species. These investigations provides the fundamental framework to link the chemistry of soil and bedrock to plant composition. This research is on-going in the Spring River and Little Red River basins of Arkansas as well as in the Prut River of Moldova and groundwater in Cairo Egypt. Assessment of Metal Contamination in Human and Environmental Samples: Using a combination of techniques Hannigan's research efforts focus on the application of new analytical tools to answer environmental problems. Unique to her approach is the development and application of laser ablation ICP-MS to the study of essential fish habitat and environmental life history reconstruction of freshwater fish. This research is supported by grants to Dr. Hannigan from the National Science Foundation. Selected Publications: Bogdevich O.P., Hannigan R.E., Moraru C.E., Izmailova D.N., Budesteanu S.M., and Cadocinicov O.P. Assessment of heavy metal and Se concentration in soil And sewage sludge. Environmental Research 89: 189-194. 2002. Hannigan, R. Trace element and rare earth element geochemistry of the surface and geothermal waters from the Taupo Volcanic Zone, North Island New Zealand. Hydrology Journal 250: 106-121, 2001. Hannigan R.E., Sholkovitz E.R. The development of middle rare earth element enrichments in freshwaters: weathering of phosphate minerals. Chemical Geology 175: 495-508. 2001. Harden, W., Russ, J., and Hannigan, R. 2003. Application of Dynamic Reaction Cell ICP-MS for metals analysis in human hair: Direct analysis by laser ablation. Submitted to the Journal of Atomic and Analytical Spectrometry. Hannigan, R., Bickford, N., and Hamilton, B. 2003. Otolith Microchemistry and Freshwater Fish Life History. Gordon Research Conference - Catchment Hydrology. Hannigan, R. and Bickford, N. 2003. Linkages Between Bioavailability And Equilibrium Kinetics In A Freshwater System. Environmental Geosciences. In Press. December 2003. Contact Information Robyn Hannigan, Ph.D. Arkansas State University Phone: (870) 972-3086 |