Ammonia nitrogen is an important pollutant in water, and its content directly affects the quality of the water. The ammonia nitrogen analyzer is an instrument used to measure the ammonia nitrogen content in water. Its working principle is to use chemical reactions to convert ammonia nitrogen in the water sample into ammonia, and measure the concentration of the generated ammonia to calculate the ammonia nitrogen content in the water sample. Specifically, ammonia nitrogen testers typically use indicator or colorimetric methods for measurement.
The following are two commonly used measurement methods:
Indicator method
The indicator method is a method that converts ammonia nitrogen in water into nitrite and nitrate by adding oxidants and indicators, and then uses colorimetry to determine the content of the generated nitrite and nitrate, thereby calculating the ammonia nitrogen content in the water sample.
The specific steps are as follows:
Take a certain amount of water sample and add a certain amount of oxidant and indicator;
Within a certain period of time, the oxidant will oxidize the ammonia nitrogen in the water sample to nitrite and nitrate, resulting in color changes;
Determine the content of nitrite and nitrate produced by colorimetric method to calculate the ammonia nitrogen content in the water sample.
colorimetry
Colorimetric method is a method of calculating the ammonia nitrogen content in water samples by adding reagents containing mercury ions to react with ammonia and mercury ions to generate amalgam red compounds. The absorbance of the amalgam red compounds is then measured using colorimetric method.
The specific steps are as follows:
Take a certain amount of water sample and add reagents containing mercury ions (such as mercuric thiocyanate);
Mercurous thiocyanate can react with ammonia in water to form a deep red compound. The absorbance of the red compound is measured by colorimetry to calculate the ammonia nitrogen content in the water sample.
It should be noted that different types of ammonia nitrogen testers may use different measurement methods and steps. In addition, to ensure the accuracy of measurement, the use of ammonia nitrogen measuring instruments requires strict adherence to operating procedures and calibration and maintenance of the instruments.
