Phosphorus in nature

Figure 5. Photograph of an autonomous lab-on-a-chip system (top) configured for remote field monitoring of phosphorus in natural waters. Bottom is a closeup of the detector area of the system.

Cabrera et al. [95] determined total dissolved and suspended phosphorus in natural waters by a method involving digestion with hydrogen peroxide and sulphuric acid, errors may be caused by adsorption of phosphorus on hydrous iron and aluminium oxides formed during neutralization prior to filtration. It is proposed that this can be prevented by adding extra sulphuric acid after neutralization, to dissolve such oxides and release the adsorbed phosphorus into solution. 

Koroleff, F. (1970) Determination of Total Phosphorus in Natural Waters by Means of Persulfate Oxidation. International Council for the Exploration of the Sea (ICES), Report No. 3. 

Davis, J.E. (2000) Geochemical controls on arsenic and phosphorus in natural and engineered systems. Master s Thesis, Virginia Polytechnic Institute, Environmental Engineering, Blacksburg, VA. 

Solorzano, L., and Sharp, J. H. (1980b). Determination of total dissolved phosphorus and particulate phosphorus in natural waters. Limnol. Oceanogr. 25,754-758. 

Valderrama, J. C. (1981).The simultaneous analysis of total nitrogen and total phosphorus in natural waters. Mar. Chem. 10,109-122. 

McKelvie, I.D., Peat, D.M., and Worsfold, PJ. (1995) Techniques for the quantification and speciation of phosphorus in natural waters. Anal. Proc. Inch Anal. Comm. 32, 437 145. 

Zhang H., Davison W., Gadi R., and Kobayashi T. (1998) In situ measurement of dissolved phosphorus in natural waters using DGT. Analyt. Chem. Acta 370, 29-38. 

The spectrophotometric methods for the determination (and speciation) of phosphorus in natural waters have been compared with other analytical techniques [144]. 

W. Lei, K. Fujiwara, K. Fuwa, Determination of phosphorus in natural waters by long-capillary-cell absorption spectrometry, Anal. Chem. 55 (1983) 951. 

Sample dissolution and analyte conversion to a more easily detected species, e.g., the sequential injection determination of total nitrogen in wastewaters involving Kjeldahl oxidation and nitrate formation [141]. The spectrophotometric flow injection determination of organic phosphorus in natural waters [142], relying on the release of the different forms of phosphorus as orthophosphate, is another good example. 

I.D. McKelvie, B.T. Hart, T.J. Cardwell, R.W. Cattrall, Spectrophotometric determination of dissolved organic phosphorus in natural waters using in-line photooxidation and flow injection, Analyst 114 (1989) 1459. 

X-ray spectra of phosphorus in natural organic molecules. The P NEXAFS spectroscopic studies conducted on isolated humic substances and soil organic molecules indicate that the primary form of P is phosphate and phosphonate (Fig. 24 Myneni and Martinez 1999). When compared to humic substances from soil systems, the fluvial humic substances exhibit phosphonate as one of the important components. However, phosphonate constitutes only a minor fraction of total P in humic substances. Soil samples also exhibit features that correspond to polyphosphate. Another study conducted using NEXAFS spectroscopy at the P absorption edge suggested that marine sediments and humic materials do not exhibit phosphonate and the P NEXAFS spectra of these samples more closely resembled that of hydroxyapatite (Vairavamurthy 1999). 

Bikbulatov, E.S., 1974. On estimation of total phosphorus in natural waters Gidrokhim. Mater., 60 167—173 (in Russian). 

Ormaza-Conzalez, F.l. and Statham, P.J. (1991) Determination of dissolved inorganic phosphorus in natural waters at nanomolar concen-... 

Shan, Y., McKelvie, I.D. and Hart, B.T. (1994) Determination of alkaline phosphatase hydrolysable-phosphorus in natural water systems by enzymatic flow injection. Limnology and Oceanography 39, 1993-2000. 

White, E. and Payne, C. (1 980) Distribution and biological availability of reactive high molecular weight phosphorus in natural waters in New Zealand. Canadian Journal of Fisheries and Aquatic Sciences 37, 664-669. 

We noted earlier that mass spectrometry had not been used to any extent in speciation studies of organic phosphorus in natural environments. Here we define phosphorus speciation as the determination of actual molecular formulas and structures of molecules containing phosphorus, and not the more commonly accepted, broad classes of phosphorus such as filterable reactive phosphorus, total filterable phosphorus, filterable organic phosphorus, etc. While a few studies have focused on particular classes of organic phosphorus, such as the inositol phosphates, we are not aware of any attempt to broadly speciate... 

Cross, A.F. and Schlesinger, W.H. (1995) A literature review and evaluation of the Medley fractionation applications to the biogeochemical cycle of soil-phosphorus in natural ecosystems. Geoderma 64, 197-214. 

Figure 2 Representation of a steady-state concentration gradient in a DGT device. Ag is the thickness of the ion-permeable gei membrane, <5 is the thickness of the diffusive boundary layer, and C is the concentration of reactive phosphorus species in the bulk of solution. (Adapted from Zhang H, Davison W, Gadi R, and Ko bay as hi T (1998) In-situ measurement of dissolved phosphorus in natural waters using DGT. Analytica ChimicaActa 370 29-38, with permission from Elsevier.)...

Freeman, P.R. et al.. Flow-injection technique for determination of low levels of phosphorus in natural waters, Analytica Chimica Acta 234, 409,1990. 

McKelvie, I.D. et al., Spectrophotometric determination of dissolved organic phosphorus in natural waters using in-line photo-oxidation and flow injection. Analyst 114, 1459, 1989. Aminot, A. and Kerouel, R., An automated photo-oxidation method for the determination of dissolved organic phosphorus in marine and fresh water. Marine Chemistry 76, 113, 2001. Solorzano, L. and Strickland, J.D., Polyphosphate in seawater. Limnology and Oceanography 13, 515,1968. 

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