Anions in non saline waters - Determination of Anions in Natural and Treated Waters - page 239

2.63.10 High performance liquid chromatography
The application of this technique is discussed under multianion analysis in sections
13.1.1.3, 13.1.1.4 and 13.1.1.5.
2.63.11 Ion exclusion chromatography
Kim and Kim [541] have described an extremely sensitive determination of nitrite in
drinking water (tap water and underground water) and environmental samples (rain, lake
water, and soil) by ion exclusion chromatography with electrochemical detection.
Potential interferences in the determination of nitrite by the standard spectrophotometric
method or by the ion exchange chromatographic method with either conductivity or
ultraviolet detection were eliminated. The detection limit was 0.1µg L −1 without
preconcentration. No nitrite was observed from tap water or underground drinking water.
The recoveries of nitrite added to tap water at 0.02, 0.1 and 1mg L −1 levels were between
96 and 104.5%. The average coefficient of variation was 4.7%. The recovery results were
in good agreement with those obtained by the standard spectrophoto-metric method.
Nitrite concentrations between 0.068 and 0.19mg L −1 were observed in rain within a
week period. A greater variation, between 0.015 and 0.26mg L −1 was observed in lake
water.
2.63.12 Micelle chromatography
The application of this technique is discussed under multianion analysis in section
13.5.1.2.
2.63.13 Gas chromatography
Funazo et al. [542] have given details of a procedure for the determination of nitrite in
river water by gas chromatography after reaction with m- nitroaniline and
hypophosphorous acid to convert nitrite to nitrobenzene.
It is well known that nitrite diazotises aromatic amines in acidic media and that the
resulting diazonium ions are reduced by hypophosphorous acid to form benzene
derivatives. The reactions are formulated as follows.