Research

• Transition metal porphyrins.
• Organic geochemistry.
• Synthesis, reactions and spectrometry of the transition-metal prophyrins and related materials.
• Biogeochemistry of tetrapyrrole pigments.

Current research involves the analysis of the photosynthetic pigments, the chlorophylls and carotenoids, in the waters and sediments of Lake Okeechobee and Florida Bay, two of the major aquatic/marine natural resources of southern Florida. Data from these analyses are utilized in chemotaxonomy, assessing photoautotrophic community structure specifically, and paleolimnology-paleooceanograpy, unravelling past environments and primary productivity.

Other continuing research includes all aspects of the chemistry, biochemistry, and geochemistry of the tetrapyrrole pigments (chlorophylls, hemes, porphyrins), especially as related to fossil fuel (petroleum, coal) research.

Techniques include HPLC, PDA, UV/VIS, NMR, MS, microscopy and general wet-chemical methodologies.

Selected Publications

C. E. Carraher Jr., J. W. Louda, D. C. Sterling, E. W. Baker, A. Rivalta and J. Q. Zhang: "Electron Impact Mass Spectrometry of Condensation Metal-Containing Polymers" In: Metal-Containing Polymeric Materials,  pp. 409-420 (1996 - ACS Washington D.C.)

N. M. Winfree, J. W. Louda, E. W. Baker, A. Steinman, K. E. Havens: "Application of Clorophyll and Carotenoid Pigments for the Chemotaxonomic Assessment of the Waters and Surficial Sediments of Lake Okeechobee, Florida" In: Eganhouse, R. (Ed.) Application of Molecular Markers in Environmental Geochemistry, pp 77-91. (1997 - ACS Symposium series #671, ACS Washington D. C.) 

A. Steinman, K. E. Havens, J. W. Louda, N. M. Winfree, E. W. Baker: "Characterization of the Photoautotropphic Bacterial Communities in a Sub-tropical Lake (Lake Okeechobee, Florida)" In: Can. J. Fish Aquat. Sci. Vol. 55, pp 206-219, 1998

J. W. Louda, J. Li, L. Liu, M. N. Winfree, E. W. Baker: "Chlorophyll Degradation during Senescence and Death" In: Org. Geochem. Vol. 29, pp 1233-1251, 1998

K. E. Havens, A. Steinman, H. J. Carrick, J. W. Louda, E. W. Baker: "A Comparative Analysis of Periphyton Communities in a Subtropical Lake Using HPLC Analysis and Microscopic Cell Counts" Accepted in: Aquatic Sciences (1999)

J. W. Louda, J. W. Loitz, D. T. Rudnick, E. W. Baker: "Early Diagenetic Alteration of Chlorophyll-a in a Comtemporaneous Marl System, Florida Bay" In review: Org. Geochem. (2000)