Micro-chemical test for nitrate: Difference between revisions

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Author: [[user:CBlaeuer| Christine Bläuer]]<br>
Author: [[user:CBlaeuer| Christine Bläuer]]<br>
 
 
{{underConstruction}}
 
back to [[Micro-chemical testing]]
back to [[Micro-chemical testing]]


More information about the necessary equipment and materials see Article Micro-chemistry.  
Fpr more information on the required equipment and materials see the Micro-chemistry article.  


== Procedure ==
== Procedure ==
   
   
Evaporate the test drop to complete dryness. Place 1 or 2 crystals of diphenylamine[1] on the residue and add 1 drop of concentrated sulfuric acid.
Evaporate the sample test drop to complete dryness. Place 1 or 2 crystals of diphenylamine[1] on the residue and add 1 drop of concentrated sulfuric acid.
If NO3- is present the solution instantly turn blue to dark violet.  


== Substances that may inhibit the test or affect its delicacy: ==
If NO<sub>3</sub><sup>-</sup> is present the solution instantly turns blue to dark violet or purple.
 
 
'''''Substances that may inhibit the test or affect its sensitivity:'''''
   
   
The reaction is very sensitive but not very specific, as e.g. nitrites and other oxidizing reagents like chlorates or organic contaminants can produce the same color reaction. In our context, and especially when the micro-chemical test has for an aim to confirm the nature of microscopically determined salt phases.  
The reaction is very sensitive but not very specific, as other oxidizing reagents can produce the same color. In our context the test is usually adequate, especially when the micro-chemical test has the aim of confirming the nature of microscopically determined salt phases present.  


== Important notice on waste disposal ==
== Important notice on waste disposal ==
   
   
Diphenylamine is a poison. The test drops have to be collected in a separate waste container and disposed off accordingly (not in the canalization!). For each of these tests only one or two milliliters of waste water are produced, that can be collected and periodically disposed off. It should be no problem to find a bigger laboratory that will accept such small amounts of waste and handle them accordingly.  
Diphenylamine is poisonous. The test drops have to be collected in a separate waste container and disposed of accordingly (not down the drain!). For each of these tests only one or two milliliters of waste water are produced, that can be collected and periodically disposed off. It should be no problem to find a bigger laboratory that will accept such small amounts of waste and handle them appropriately.  


== Literature ==
== Literature ==
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[[category:Bläuer,Christine]][[category:inProgress]][[category: microchemistry]]
[[category:Bläuer,Christine]][[category:approved]][[category: microchemistry]]

Revision as of 10:38, 20 September 2013

Author: Christine Bläuer

back to Micro-chemical testing

Fpr more information on the required equipment and materials see the Micro-chemistry article.

Procedure

Evaporate the sample test drop to complete dryness. Place 1 or 2 crystals of diphenylamine[1] on the residue and add 1 drop of concentrated sulfuric acid.

If NO3- is present the solution instantly turns blue to dark violet or purple.


Substances that may inhibit the test or affect its sensitivity:

The reaction is very sensitive but not very specific, as other oxidizing reagents can produce the same color. In our context the test is usually adequate, especially when the micro-chemical test has the aim of confirming the nature of microscopically determined salt phases present.

Important notice on waste disposal

Diphenylamine is poisonous. The test drops have to be collected in a separate waste container and disposed of accordingly (not down the drain!). For each of these tests only one or two milliliters of waste water are produced, that can be collected and periodically disposed off. It should be no problem to find a bigger laboratory that will accept such small amounts of waste and handle them appropriately.

Literature