Nitrogen compounds natural organic matter, protein

Most of the organic nitrogen in natural waters is bound to or built into structural components of humic substances (Bronk, 2002 Schnitzer, 1985). It has been demonstrated both in laboratory experiments and in field observations that proteinaceous matter bound to humic substances becomes bioresistant (Carlson et al., 1985 Hubberten et al., 1994). In pioneering studies on DON phototransformation Amador et al. (1989, 1991) showed that a significant part of amino acids associated with humic matter becomes bioavailable after irradiation. On the other hand, longterm irradiation of a mixture of protein and DOM compounds resulted in decreased bioavailability (Keil and Kirchman, 1994). The loss of bioavadabihty of the protein required presence of DOM, supporting that the DOM either interacted direcdy... 

Raw cotton contains, in addition to cellulose, the usual constituents of a vegetable cell. These are oil and wax, pectoses and pectins, proteins and simpler related nitrogen compounds, organic acids, mineral matter, and natural colouring matter. Cotton yarns or piece goods may contain, in addition, adventitious dirt, size, and machine oil. The approximate composition of raw cotton is as follows ... 

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