Page 84 - Pharmaceutical Analytical Chemistry III

[B] NITRITE IN WATER :

* SOURCES AND SIGNIFICANCE :
 Nitrification

It originates from the decomposition of living materials. It is
a relatively toxic intermediate formed in the bacterial
oxidation of :
proteins → ammonium → nitrite → nitrate.
Nitrite is oxidized during water treatment and should not be
detectable. Its presence indicates recent animal pollution.

 Toxicity
 Nitrite causes methaemoglobinaemia (cyanosis) (A condition in

which haemoglobin is converted to methaemoglobin that is
incapable of transpoting oxygen in the blood)