Inorganic ion detection system and methods

A method for the separation and detection of nitrate, perchlorate, azide, chloride and chlorate anions in a sample using electrophoresis, the method comprising a sample processing sequence which comprises:

• introducing a sample and a background electrolyte comprising polyethyleneimine into a fused silica capillary separation channel having an internal diameter of from 20 μm to 30 μm, coated with alternating layers of a cationic polymer and an anionic polymer, wherein a first layer and a final layer of the fused silica capillary separation channel coating are cationic polymer layers, wherein the alternating layers consist of two cationic polymer layers and one anionic polymer layer;
• applying a voltage potential across the fused silica capillary separation channel to effect a separation of the nitrate, perchlorate, azide, chloride and chlorate anions, wherein the voltage potential provides a field strength of between 1.0 kV/cm and 3.3 kV/cm of capillary across which the voltage potential is applied;
• and
• detecting the presence of the separated nitrate, perchlorate, azide and chlorate anions, wherein the cationic polymer forming the two cationic polymer layers is a hexadimethrine polymer, and the anionic polymer forming the anionic polymer layers is a polystyrenesulfonate polymer.