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Analysis Methods of Ammonia In Environmental Samples
Analysis Methods of Ammonia In Environmental Samples

Ammonia NH3 is found in water and soil samples as NH4+ ion while in air it is found in NH3. According to environmental laws of different states for ammonia NH3 analysis and reporting considered as only NH3. Ammonia is dissolved in water soil as NH4+ while free in air only. Different commercial laboratories are confused. Ammonia is present in waste Water in higher concentration for fertilizer plants. The fertilizer plants are excusing from the law and wants some favor from Environmental Protection Agency that they will allow them to send NH4+ ( actually NH3) in waste effluent. Because they can't control ammonia in waste effluent, I have an idea to don't waste the ammonia but store it in the evaporation pond and reuse for products. By doing this company can save some amount and also protect environment. There are multiple methods for the determination of ammonia in waste water but it's up to laboratory chemist how he calibrate instrument and analyze sample.

Nesslerization

This method involves the reaction of ammonia with Nessler's reagent (K2(HgI4)), forming a yellow color. The intensity of the color is proportional to the ammonia concentration. The color can read on spectrophotometer at 425 nm wave length where standard of ammonia were already graphed. Color is produced at higher pH, while precipitation of calcium carbonate and magnesium carbonate is stay dissolved by sodium potassium tartrate. This addition of sodium potassium tartrate is depends on presence of carbonates of calcium and magnesium.

Ion-Selective Electrodes (ISE)

Ammonia-selective electrodes can measure the concentration of ammonia ions directly. This method is relatively quick and precise. This method is also done at higher pH when it free ammonia electrode sensed it. It has too much interference with waste water matrix like organic and inorganic compounds, while reading of standard is in accurate value.

Colorimetric Methods

Various colorimetric methods use chemical reactions to produce color changes proportional to ammonia concentration. Indophenol blue, Nessler's reagent and salicylate methods are examples

Titration Methods

Ammonia can be titrated with a standard acid solution, and the endpoint is determined by a pH indicator. This method is known as titrimetric analysis. pH indicators are phenolphthalein, and methyl red this a simple acid base titration.

Chemiluminescence

This method exploits the chemiluminescent reaction between ammonia and hypochlorite, producing light. The intensity of light emitted is proportional to ammonia concentration.

Amperometric Methods

Ammonia can be detected electrochemically through amperometric sensors, providing a rapid and sensitive analysis. The choice of method depends on factors like sensitivity, precision, cost, and the specific requirements of the analysis.

Three common colorimetric methods for ammonia analysis in wastewater are

Indophenol Blue Method

This method involves the reaction between ammonia and indophenol reagent, resulting in a blue color. The intensity of the color is proportional to the concentration of ammonia. Color complex can read on spectrophotometer.

Salicylate Method

In this method, ammonia reacts with salicylate to form a colored complex. The color intensity is then measured and correlated with the concentration of ammonia in the standard reading. Colorimetric methods provide a visual indication of ammonia concentration based on color changes, allowing for relatively simple and cost-effective analysis.

Nessler's reagent

This method is widely used in analytical laboratory having good accuracy and less interference and errors. According to my experience I always suggest this method for analysis of ammonia in waste water, while waste of this method is properly incinerated.

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