The Rideal Walker test is a chemical test used to detect the presence of amines (organic compounds derived from ammonia) in a sample.
Rideal walker test principle
The principle of the Rideal-Walker test relies on the unique and strong odor of the isocyanides produced during the reaction with amines.
This test is a qualitative method for identifying the presence of amines in a sample based on olfactory (smell) detection.
Materials and Reagents for rideal walker test
Reagents for rideal walker test are
- Sample containing the suspected amine
- Chloroform (CHCl3)
- Sodium hypobromite (NaOBr) solution
- A test tube
- A stopper for the test tube
- A source of gentle heat (e.g., water bath)
- A source of fume extraction
Rideal walker test procedure
Here’s the Rideal walker test procedure for conducting in microbiology laboratory.
- Take a clean and dry test tube.
- Add a small amount of your sample (the substance you suspect contains an amine) to the test tube. The amount of sample can vary but should be a small quantity.
- Add an equal volume of chloroform (CHCl3) to the test tube. The chloroform will help in the conversion of the amine to isocyanides.
- Carefully add a small amount of sodium hypobromite (NaOBr) solution to the test tube. Use caution when handling sodium hypobromite, as it can be a hazardous chemical.
- Place a stopper on the test tube to seal it.
- Gently heat the test tube. This can be done by immersing the test tube in a water bath or heating it with a gentle flame. Do not heat it too vigorously.
- As the reaction occurs, the amine in the sample will react with chloroform and sodium hypobromite, producing isocyanides. These isocyanides have a strong and unpleasant odor.
- Carefully unstopper the test tube and waft the fumes that escape towards your nose.
- If you detect the foul odor of isocyanides, it indicates the presence of an amine in the sample.
- Dispose of the contents safely, as isocyanides can be hazardous.
Here’s the video of rideal Walker test procedure
NOTE: The Rideal-Walker test is a qualitative test based on odor detection, and it’s important to handle the reagents and the reaction products with care, as some of them may be harmful.