Total dissolved phosphorus , marine

Eberlein and Kattner [194] described an automated method for the determination of orthophosphate and total dissolved phosphorus in the marine environment. Separate aliquots of filtered seawater samples were used for the determination orthophosphate and total dissolved phosphorus in the concentration range 0.01-5 xg/l phosphorus. The digestion mixture for total dissolved phosphorus consisted of sodium hydroxide (1.5 g), potassium peroxidisulfate (5 g) and boric acid (3 g) dissolved in doubly distilled water (100 ml). Seawater samples (50 ml) were mixed with the digestion reagent, heated under pressure at 115-120 °C for 2 h, cooled, and stored before determination in the autoanalyser system. For total phosphorus, extra ascorbic acid was added to the aerosol water of the autoanalyser manifold before the reagents used for the molybdenum blue reaction were added. For measurement of orthophosphate, a phosphate working reagent composed of sulfuric acid, ammonium molyb-... 

The role of the atmosphere in the phosphorus cycle seems to be poorly understood. Since it does not exist in the form of stable gaseous compounds, phosphorus in the atmosphere is either adsorbed on particulate matter, e.g. dust (including pollen) and exhaust fumes or dissolved in sea-spray. The fallout of phosphorus, as dry deposition and precipitation, has been estimated to be within the range 3.6—9.2 Tg P y for terrestrial ecosystems, 0.054— 0.140 Tg P y for freshwater ecosystems, and 2.6—3.5 Tg y" for the marine ecosystem. This gives a total fallout from the atmosphere of 6.3—12.8 Tg P y i (Pierrou, 1976). It should be noted, however, that Emery et al. (1955)... 

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