Nutrient detection

The detection principles for nitrate and phosphate into which research had already been performed have been inventoried on the basis of a literature research. A selection has been made of promising detection principles for both components using a number of selection criteria for both salt and fresh water applications. In each case, a differentation was made between those principles which could be considered in a monitor design, and principles which could be used in a sensor design. Apart from monitor systems based on colour reactions, a chemiluminescence monitor for nitrate is technically the most feasible. Such a monitor is also the most promising from the point of view of its sensitivity and selectivity. The use of an enzymatic conversion appears to be an advantage in the development of sensors for phosphate and nitrate, considering the high selectivity which accompanies it. Such a development is however full of risks, considering stability and detection limit. An enzyme sensor for nitrate has a higher chance of succes than the analogous sensor for phosphate in terms of stability and sensitivity.