POTENTIOMETRIC DETECTION OF ALIPHATIC-AMINES BY FLOW-INJECTION ANALYSIS AND ION-INTERACTION CHROMATOGRAPHY WITH A METALLIC COPPER ELECTRODE

The detection of aliphatic amines in flow systems with a potentiometri c method based on a metallic copper wire electrode is described. The e lectrode is shown to give sensitive response toward aliphatic amines i n flow injection analysis. The parameters affecting the response chara cteristics of the electrode such as the pH of the carrier, the concent ration of an ion-interaction reagent and the injection volume were inv estigated. The metallic copper electrode was applied to the detection of amines after separation by ion-interaction chromatography with a mo bile phase containing a low concentration of octylammonium salicylate in unbuffered solution. Detection limits in the range of 0.5-1.0 nmol were obtained in the presence of 0.3 mM octylammonium salicylate at a pH of 6.0 and a flow-rate of 0.3 ml/min. A comparison of the potentiom etric detection with conventional UV is given, showing comparable sens itivities, The potentiometric method offers a low cost, easily constru cted detector with some possible applications.