Investigation of the chemical identity of soluble organophosphorus compounds found in natural waters

The ability of various laboratory algal cultures to generate substantial quantities of dissolved organic phosphorus (DOP) compounds has been demonstrated. After isolation and concentration of these compounds by low pressure filtration, freeze drying and redissolution, molecular size profiles on Sephadex gels were obtained. Comparison between DOP and inositol phosphate profiles on Sephadex G-25 prompted specific studies for the presence of inositol phosphates in the culture solutions. Alkaline bromination techniques established in soil chemistry research were employed in conjunction with Sephadex gel filtration to generate circumstantial evidence for the presence of inositol monophosphate and the absence of inositol hexaphosphate. The results obtained in conjunction with preliminary volatile derivative studies have provided the base for continued studies on the specific chemical nature of DOP compounds in aqueous systems.U.S. Department of the InteriorU.S. Geological SurveyOpe

Gas chromatography of volatile metal chelates: Application of a new technique to metal analysis in natural waters

Originally, the application of commercially available monothiohexafluoroacetylacetone (HFAS) and its formation of volatile chelates with metals of environmental significance to rapid, multi-element analysis was under investigation. Inability to reproduce published results for the Nickel chelate led to critical examination of the chelating agent and ultimately to withdrawal of the compound from the commercial market when its identity and purity were found to be questionable. Independent synthesis of HFAS was unsuccessful and initial project objectives were abandoned. Project objectives were redirected to verification and extension of previous studies involving the lead chelate of 2,2,6,6-tetramethylheptane-3,5-dione (PIV) . Extraction studies were conducted using flameless atomization atomic absorption for analysis but are of questionable value as a result of analytical inconsistencies. Gas chromatographic studies indicated previously reported synthesis of Pb(PIV)₂ had likely not been achieved. Both HFAS and PIV studies were unsuccessful and have resulted in programs of independent synthesis and continued research at The University of Tennessee where the Principal Investigator is now in residence.U.S. Department of the InteriorU.S. Geological SurveyOpe