Buffer Component
An organic salt acts as a mobile phase additive in liquid chromatography to facilitate the ionization of analytes during mass spectrometry. Use of ammonium formate ensures that the pH of the solvent remains stable (improving the repeatability of retention times for polar compounds found in textile dyes). This chemical allows for the formation of ammonium adducts which often provide a clearer signal than simple protonated ions in certain detection modes.
Chromatographic Performance
Volatile properties of the salt make it ideal for electrospray ionization because it evaporates completely without clogging the detector interface. When detecting perfluorinated chemicals in fabric extracts, ammonium formate prevents the suppression of signals that occurs with less volatile buffers. Its presence in the mobile phase assists in the separation of short chain and long chain molecules.
Mill Application
Laboratories preparing samples from wastewater or finished garments rely on high purity grades of this additive to avoid background noise. If the concentration of ammonium formate deviates from the standard operating procedure, the shift in ionic strength can cause peaks to overlap.
Technical Limit
The salt is typically used in concentrations ranging from 2 to 10 millimolar to provide sufficient buffering without precipitating in the presence of organic solvents. High concentrations of the additive might lead to ion suppression for some specific target molecules. The purity level of the solid reagent determines the baseline stability in ultra high performance liquid chromatography.
