Anions in potable waters - Determination of Anions in Natural and Treated Waters - page 500

Fig. 7.9 Absorption spectra of nitrate and nitrite standard solutions containing
1mg L −1 of nitrogen
Source: Reproduced with permission from the Royal Society of
Chemistry [46]
Results obtained for nitrate by ultraviolet spectroscopy and spectrophotometry are
compared in Table 7.11. Good agreement was obtained for all ground water samples
analysed.
7.18.2 Ultraviolet spectroscopy
This technique has been investigated by several workers [47-49].
R ennie et al. [48] describe a method for determining down to 6µg L −1 nitrate nitrogen
in raw and potable waters which uses an activated carbonfilter, at an elevated pH, to
eliminate interference from organic matter. Interference from several cations that are
precipitated out of solution is also removed by this system. The results obtained using the