This paper describes a simple spectrophotometric procedure for determining NO3--N in water samples. In the proposed method, NO2--N of a water sample is first removed from the water with sulfamic acid. Then, NO3--N is reduced to NO2--N using vanadium (III) chloride and a detection reagent is added. When rapid collection of data is necessary, this method can be adapted to a microtechnique using a 96-well microplate, resulting in a detection limit of 5 NO3--N mg/l. Using a larger volume spectrophotometer cell (5 cm) lowers the detection limit to 0.5 NO3--N mg/l. The proposed method is applicable for routine analysis of water in aquaculture systems and wastewaters in which medium-high NO3--N concentrations are expected. Benefits of the method are reduction of the laborious preparation and avoidance of contact with the harmful substances typical of the cadmium reduction method.
A direct spectrophotometric assay for evaluating nitrate-ntrogen in intensive aquaculture systems
CECCHINI, Stefano
;
2012-01-01
Abstract
This paper describes a simple spectrophotometric procedure for determining NO3--N in water samples. In the proposed method, NO2--N of a water sample is first removed from the water with sulfamic acid. Then, NO3--N is reduced to NO2--N using vanadium (III) chloride and a detection reagent is added. When rapid collection of data is necessary, this method can be adapted to a microtechnique using a 96-well microplate, resulting in a detection limit of 5 NO3--N mg/l. Using a larger volume spectrophotometer cell (5 cm) lowers the detection limit to 0.5 NO3--N mg/l. The proposed method is applicable for routine analysis of water in aquaculture systems and wastewaters in which medium-high NO3--N concentrations are expected. Benefits of the method are reduction of the laborious preparation and avoidance of contact with the harmful substances typical of the cadmium reduction method.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
