Nitrate, Nitrite and Ammonia in Various Samples ('03)

Kristi Tompkins and Rashelle Simmons

Nitrogen compounds are in a delicate balance in water which contains living organisms.  They can also be found in other water sources especially if runoff is evident in rivers and lakes.  The runoff can include many nitrogen contaminants like fertilizer, sewage, garbage and industrial waste (6).  Nitrates and nitrites are also results of the erosion of natural deposits (2).  There are several methods for determining the difference nitrogen compounds in water.  For this experiment, the phenate spectrophotometric method was chosen for ammonia nitrogen content for its sensitivity over the Nessler method (10).  However, color development proved to be quite dependent on reagent quality and was not successful in this experiment.  The alternative, the powder pillows, turned out to be most sensitive offering a detection limit of 0.01 mg/L. Nitrite/nitrate nitrogen concentrations were also determined spectrophotometrically using cadmium reduction.  Cadmium reduction was the only method available for nitrate analysis.  Two procedures existed included the powder pillows and mixing reagents from scratch.  The last being too labor intensive.  In this method nitrate is converted into  nitrate therefore the results includes nitrogen from both sources.