Abstract

This paper focuses on the comparative determination of nitrate anion concentration from selected wells and points along the Kimondi River using UV-Visible spectrophotometric method. The areas monitored were Tulon, Sitatunga swamp, Sironoi, Kimondi Bridge, kipchabo tea factory and Samoo. This research was to determine whether nitrate anions in water are beyond the threshold limit which is harmful to both plant and animal life. Relatively high concentrations of NO₃ usually have their origin in processes of organic pollution and excessive use of inorganic fertilizers. In the case of agricultural areas for example, Nandi County where our analysis was based, these activities may generate great quantities of nitrates. The water was sampled from both the river point and one selected borehole in the respective areas. Three samples were obtained from each of the sampling points and were analyzed for nitrate using the UV-Visible spectrophotometer set at 420 nm. The average of the three-absorbance values was computed and converted to concentration in mg/L. The research showed that levels of nitrate ion in both river and well waters were below the threshold limits.

Key words: Nitrate anion, threshold limit, UV-Visible spectrophotometric method.