Nitrogen in seawater

The Adamski [13] procedure is semiautomated. It gives an accuracy of 8.1% and a precision of 8.2% for seawater samples spiked with 3-35 p,g/l organic nitrogen. This procedure is based on the indophenol blue method and was employed using a Technicon AutoAnalyzer II system with the appropriate accessories. Various workers have described automated procedures for determination of low levels of organic nitrogen in seawater [15,16]. 

Shepherd and Davies [26] have described a semiautomated version of the alkaline peroxodisulfate procedure for the determination of total dissolved organic nitrogen in seawater. These workers carried out experiments on a range of contaminated and clean seawaters using a version [27] of Koroleff s [24] alkaline peroxodisulfate oxidation technique. 

Frankovitch and Jones [33] have presented a rapid automated method for the determination of total combined nitrogen in seawater. The method has a detection limit of 2 pM. 

The oxidation munber of nitrogen in all organic compoimds is -III. Most of the dissolved nitrogen in seawater is in the form of DON except in the deep ocean where nitrate concentrations are very high. The mean smfece water DON concentration is 6 2 p,M N and in deep waters it is 4 2 p,M N. PON generally represents only a small fraction of the fixed nitrogen pool. 

Content of dissolved nitrogen in seawater (mL/L) Near the equator High latitudes 14.1 8.2... 

Figure 7 The solubility of nitrogen in seawater as a function of temperature and salinity...

Walsh, T. W. (1989). Total dissolved nitrogen in seawater A new high temperature combustion method and a comparison with photo-oxidation. Mar. Chem. 29, 295—311. 

All locating scents commonly used in ion-exchange chromatography have been tested for use as reagents in determining total amino nitrogen in seawater. 

Seasonal Distributions of Dissolved Inorganic Nitrogen in Seawaters... 

A. Tovar, C. Moreno, M.P. Manuel-Vez, M. Garcia-Vargas, A simple automated method for the speciation of dissolved inorganic nitrogen in seawater. Anal. Chim. Acta 469 (2002) 235-242. 

Pike S.M. and Moran S.B. 1997. Use of Poretics (super R) 0.7 jun pore size glass fiber filters for determination of particulate organic carbon and nitrogen in seawater and freshwater. Mar. Chem. 57 355-360. 

H., Parker A.E., Primm O., Pujo-Pay M., Savidge W.B., Seitzinger S., Spyres G., and Styles R. 2004. A direct instrument comparison for measurement of total dissolved nitrogen in seawater. 

Shepherd R.J. and Davies I.M. 1981. A semiautomatic alkaline peroxodisulphate method for the routine determination of total dissolved nitrogen in seawater. Anal. Chim. Acta 130 55-63. 

In some cases, nitrogen or even carbon may be limiting nntrients, the presence of which determines the rate of algal growth. This is particnlarly trne of nitrogen in seawater. In seawater, micronutrients, particularly iron, may be limiting. 

In some cases, nitrogen or even carbon may be limiting nutrients. This is particularly true of nitrogen in seawater. 

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