This project is designed to redress the scarcity of information on the composition, structure and cycling of compounds of marine sedimentary organic-P. Standard methods for isolating soluble organic-P are being coupled with analytical pyrolysis of the insoluble macromolecular fraction of organic-P, chromatographic (HPLC, GC) and direct spectroscopic (31P-NMR,MS) methods to characterize organic-P compounds in marine pore waters and sediments. Chemical structure and composition dictate whether organic-P compounds are labile or refractory with respect to microbially mediated degradation, and control recycling of sedimentary organic-P into the water column. Composition and chemical structure will therefore, in large part, control the ultimate burial rate of refractory organic-P. Construction of a material balance for the sedimentary organic-P reservoir based on detailed compositional/structural information of constituent organic-P compounds will permit documentation of the remineralization of the labile versus the refractory organic-P reservoirs.
