Dissolved inorganic phosphorus

Fractionation of milk and titration of the fractions have been of considerable value. Rice and Markley (1924) made an attempt to assign contributions of the various milk components to titratable acidity. One scheme utilizes oxalate to precipitate calcium and rennet to remove the calcium caseinate phosphate micelles (Horst 1947 Ling 1936 Pyne and Ryan 1950). As formulated by Ling, the scheme involves titrations of milk, oxalated milk, rennet whey, and oxalated rennet whey to the phenolphthalein endpoint. From such titrations, Ling calculated that the caseinate contributed about 0.8 mEq of the total titer of 2.2 mEq/100 ml (0.19% lactic acid) in certain milks that he analyzed. These data are consistent with calculations based on the concentrations of phosphate and proteins present (Walstra and Jenness 1984). The casein, serum proteins, colloidal inorganic phosphorus, and dissolved inorganic phosphorus were accounted for by van der Have et al (1979) in their equation relating the titratable acidity of individual cow s milks to the composition. The casein and phosphates account for the major part of the titratable acidity of fresh milk. 

Figure 11.10 Negative correlations between dissolved inorganic phosphorus (pM) and oxygen (mL L-1) concentrations in bottom waters of the Baltic Sea. (Modified from Conley et al., 2002.)...

In the lower reaches of the Genesee River, the results of the extractions suggest that substances other than hydrous oxides are phosphorus sinks. This is evident where the amount of sediment phosphorus extracted by hydrochloric acid steadily increases down river, while the oxalate extractable phosphorus remains relatively constant. Schwertmann (2 ) emphasized that the results of such procedures are best considered as a measure of the relative amount of a phase or, more generally, a measure of an element s reactivity in a sediment under carefully controlled conditions. Laboratory experiments (Figure 8) show that phosphorus uptake by calcium carbonate, under simulated natural conditions, proceeds slowly. The large hydrochloric acid extractable component observed at Rochester may arise from slow uptake and subsequent mineralization of dissolved inorganic phosphorus by carbonate minerals. 

Dissolved inorganic phosphorus (DIP) 0.7 pmol L l DeMaster and Pope, 1996... 

Figure 33.15 The growth rate ofdiazotrophs as a function of temperature and dissolved inorganic phosphorus concentration in the Fennel et al. (2002) model. Reproduced from Fennel et al. (2002) with permission.

Although there is a tendency to consider dissolved inorganic phosphorus (DIP, measured... 

Estimates for the partitioning of the oceanic reservoir between dissolved inorganic phosphorus and particulate phosphorus are given in references b and d as follows (2,581-2,600) X 10 mol dissolved inorganic phosphoms (b, d) and (20-21) X 10 mol particulate phosphorus (d, b). 

A profile of the S C of Die in the Pacific Ocean showing the surface enrichment and the correlation with DIC, O2 and dissolved inorganic phosphorus (DIP). Redrawn from Broecker and Peng (1982). 

Dissolved inorganic phosphorus, DIP, versus dissolved inorganic nitrate (DIN, which is mostly NOf) concentrations in the world s oceans between 1000 and 5000 m (plotted using Ocean Data View). Dark points represent data from the North Atlantic and lighter points are data from the North Pacific. Lines indicate linear regressions through the data from the Atlantic and Pacific. 

Fig. 6.5 (a) Dissolved silicate and (b) dissolved inorganic phosphorus (DIP) plotted against salinity in the Great Ouse Estuary (eastern England), illustrating non-conservative removal. 

Fig. 6.30 Oxygen and phosphorus concentrations in the Baltic Sea. Dark line through data is a regression line and thin line marks zero 02 concentration. DIP, dissolved inorganic phosphorus. Data plots after Fonselius (1981) and Nehring (1981), with permission from Elsevier Science.

Figure 5. Average rate of planktonic nitrogen fixation plotted vs. average concentration of dissolved inorganic phosphorus (DIP) for a variety of freshwater and marine ecosvstems. Freshwater ecosystems—solid sysmbols marine ecosvstems—hollow symbols (Howarth et al. 1988).

Prastka, K., Sanders, R. and Jickells, T. (1998) Has the role of estuaries as sources or sinks of dissolved inorganic phosphorus changed over time Results of a Kd study. Marine Pollution Bulletin, 36, 718-728. 

Table 4 Turnover rates of dissolved Inorganic phosphorus (DIP) and dissolved organic phosphorus (DOP) In surface sea water ...

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

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