Dissolved Phosphorus Compounds Research Articles

The Measurement of Dissolved Phosphorus Compounds: Evidence for Hydrolysis During Storage and Implications for Analytical Definitions in Environmental Analysis

Labile organophosphorus and inorganic polyphosphate compounds have been identified as a potential source of error in the measurement of inorganic monophosphate in natural samples. To test this, a range of synthetic phosphorus containing compounds were used to prepare solutions of known composition, which were measured by three commonly used analytical methods for the determination of monophosphate in natural waters. The solutions were also measured after acidic persulphate digestion, to assess the overall recovery of phosphorus by a standard total dissolved phosphorus analysis. No significant concentration of phosphorus was detected in any of the solutions by the three monophosphate methods, when analysed within 4 h of preparation. However, when analysed after 72 h storage, about half of the selected compounds showed an increase in the monophosphate concentration. The phosphorus concentrations measured after acidic digestion were in close agreement with the formulated values for the compounds. These results indicate that the selected compounds are included in the total dissolved fraction, but may also contribute to the monophosphate fraction by hydrolysis to monophosphate in solution after storage.

Comparison of Phosphorus Dynamics in Two Oklahoma Reservoirs and a Natural Lake Varying in Abiogenic Turbidity

The rate of phosphate uptake, the immediate fate of phosphate, and the potential rate of release of phosphate from dissolved phosphorus compounds in epilimnia of two reservoirs and one natural lake in northcentral Oklahoma were compared in the summer and in the late autumn. Sangre Isle Lake is a highly productive eutrophic impoundment, Sanborn Lake is a natural lake with low phytoplanktonic productivity, and Boomer Lake is an impoundment with modest productivity that is heavily affected by clay suspensoids. Although the uptake of phosphate (radiometrically determined) was rapid in each of these lakes in summer, the fate of phosphate in Boomer Lake differed from that of the others, with much of the phosphate sorbing to suspended silts and clays rather than biota (determined by isopycnic sedimentation). Recycling of phosphate from phosphomonoesters was greatest in Sangre Isle Lake, moderate in Sanborn Lake, but was undetectable in Boomer Lake. These findings suggest that high concentrations of clay suspensoids influence the epilimnetic P dynamics in reservoirs and lakes.