If you are looking for optimized HPLC method to analyze Ammonia check our HPLC Applications library

For optimal results in HPLC analysis, it is recommended to measure absorbance at a wavelength that matches the absorption maximum of the compound(s) being analyzed. The UV spectrum shown can assist in selecting an appropriate wavelength for your analysis. Please note that certain mobile phases and buffers may block wavelengths below 230 nm, rendering absorbance measurement at these wavelengths ineffective. If detection below 230 nm is required, it is recommended to use acetonitrile and water as low UV-transparent mobile phases, with phosphoric acid and its salts, sulfuric acid, and TFA as buffers.
For some compounds, the UV-Vis Spectrum is affected by the pH of the mobile phase. The spectra presented here are measured with an acidic mobile phase that has a pH of 3 or lower.

Separation type: Liquid Chromatography Mixed-mode

Ammonia, primary and secondary amines are common compounds used as building blocks in organic synthesis. Derivatives of these compounds are used in agriculture, pharmaceutical, and chemical manufacturing. All compounds in this application are basic and hydrophilic in nature. Problems in analysis include poor peak shape, lack of retention on C18 columns, and absence of chromophores in ammonia, primary and secondary amines. Analysis of hydrophilic amines requires derivatization to provide hydrophobicity/retention and UV activity, ion-pairing reagents to provide retention. Presence of residual silanols will affect peak shape. Ammonia, methylamine, morpholine, ethylamine, diethylamine, and butylamine can be analyzed on a Primesep A HPLC column with trifluoroacetic acid in the mobile phase. Compounds in the mixture can be monitored by ELSD.

Primesep A separates ammonia and simple amines (butylamine, diethylamine, ethylamine, methylamine and morpholine) by cation exchange and reversed phase. Primesep A has an embedded strong anionic functional group which helps retain cations by polar and ion-exchange mechanisms. Excellent peak shape results with a mass spec compatible mobile phase of water, acetonitrile (MeCN, ACN) and trifluoracetic acid (TFA) with evaporative light scattering detection (ELSD).