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A positive test for nitrite is indicated by a dark brown solution, arising from the iron-nitric oxide complex ion. This test is related to the brown ring test for the nitrate ion, which forms the same complex in a ring. In contrast, nitrites turn the whole solution brown and therefore interfere with that test. [1]
The Griess test is an analytical chemistry test which detects the presence of nitrite ion in solution. One of its most important uses is the determination of nitrite in drinking water . The Griess diazotization reaction, on which the Griess reagent relies, was first described in 1858 by Peter Griess .
The nitrate anion is an oxidizer, and many tests for the nitrate anion are based on this property. However, other oxidants present in the analyte may interfere and give erroneous results. Nitrate can also be detected by first reducing it to the more reactive nitrite ion and using one of many nitrite tests. [1]
The presence of nitrites, which causes a pink color on the reagent strip pad, therefore acts as an indicator of urinary tract infection. [51] The nitrite test is quite specific, meaning that someone is likely to have a UTI if it is positive, but it is not sensitive; a negative result does not reliably indicate that the subject does not have a UTI.
The color intensity of the resulting solution is then measured by a colorimeter and checked against a calibration curve to determine the nitrite ion concentration. [ 4 ] To analyze nitrate concentrations quantitatively, the sample is first passed through a copper-cadmium column to reduce the nitrate ions quantitatively to nitrite ions, and the ...
In the NO − 3 anion, the oxidation state of the central nitrogen atom is V (+5). This corresponds to the highest possible oxidation number of nitrogen. Nitrate is a potentially powerful oxidizer as evidenced by its explosive behaviour at high temperature when it is detonated in ammonium nitrate (NH 4 NO 3), or black powder, ignited by the shock wave of a primary explosive.
Dissimilatory nitrate reduction to ammonium is a two step process, reducing NO 3 − to NO 2 − then NO 2 − to NH 4 +, though the reaction may begin with NO 2 − directly. [1] Each step is mediated by a different enzyme, the first step of dissimilatory nitrate reduction to ammonium is usually mediated by a periplasmic nitrate reductase.
The nitrite ion has the chemical formula NO − 2. Nitrite (mostly sodium nitrite) is widely used throughout chemical and pharmaceutical industries. [1] The nitrite anion is a pervasive intermediate in the nitrogen cycle in nature. The name nitrite also refers to organic compounds having the –ONO group, which are esters of nitrous acid.