Ammonia and ammonium are different forms of nitrogen. The major factor that determines the proportion of ammonia to ammonium in water is pH. The activity of the ammonia is also influenced by ionic strength and temperature. It is important to remember as un‐ionized NH 3 can be harmful to aquatic organisms, while ionized ammonium is basically ...

Ammonia (NH3) and Ammonium (NH4) are in equilibrium when dissolved in water. The proportion of NH3 and NH4+ in the sample will vary based on pressure, temperature and most importantly pH. In basic solutions ammonia is the dominant species. This is important to note when comparing to other instrumentation that may read as NH3 or NH3-N.

Ammonia exists in water as either the ammonium ion (NH4+) or the un-ionized ammonia (NH3). Un-ionized ammonia is toxic to fish, while the ammonium ion is nontoxic except at extremely high concentrations. At neutral pH 7 and ambient temperature, almost all …

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The presence of ammonia nitrogen in surface water usually indicates domestic pollution. Ammonia in ground water is normal and is due to microbiological processes. Two methods for determining ammonia, the Nessler method and the Salicylate method, are used in Hach products and procedures. Chemical Reactions: Nessler method

It may be possible to use the ammonia IntelliCAL™ ISENH3181 and ammonium IntelliCAL™ ISENH4181 probe in seawater applications. Special treatment such as distillation may be required. Links

The Nitrogen-Ammonia Ion Selective Electrode (ISE) Method Nitrogen, Ammonia-Direct Measurement ISE Electrode, Method 10001 DOC316.53.01235 and Nitrogen, Ammonia-Known Addition ISE Method 10002, ISE Electrode_DOC316.53.01234 has equivalent status for United States Evironmental Protection Agency (USEPA) wastewater reporting.

Ammonia reacts with alkaline phenol, then with sodium hypochlorite to form indophenol blue. Sodium nitroprusside (nitroferricyanide) is added to enhance sensitivity. The absorbance of the reaction product is measured at 630 nm, and is directly proportional to the original ammonia concentration in the sample.

The Ammonia (Nitrogen) Test Strips, 0-6.0 mg/L (Product # 2755325) will not detect quaternary ammonium compounds or residues. The test strips work by raising the pH of the sample to above 10 which converts all ammonium ions in the sample to free (un-ionized) ammonia.

The Nitrogen, Ammonia- Salicylate or Nessler methods use a reagent blank to zero the instrument before the reacted sample is measured. A reagent blank is deionized water plus the Nitrogen, Ammonia reagents. A possible reason for a high reagent blank measurement may a contaminated deionized water source, which is common with Ammonia chemistries.