HPLC OF PHENOLIC-COMPOUNDS WITH A MULTIEL ECTRODE ELECTROCHEMICAL DETECTOR

Reversed-phase liquid chromatography with a multielectrode electrochem ical detector was applied to the separation of phenolic compounds, inc luding methylphenols, chlorophenols and nitrophenols. A mobile phase o f methanol-0.05 M potassium dihydrogen phosphate-0.05 M dipotassium hy drogenphosphate (9:8:1, pH 7) was used at a flow rate of 0.5 ml/min.. Four porous glassy carbon electrodes placed in a series were used for coulometric measurements. Selective and sensitive detection resulted. From the hydrodynamic voltammograms of the compounds, the potential of the four electrodes was set at 550, 700, 750 and 800 mV vs. Ag/AgCl, respectively. These analytical conditions enabled the detection of 2,4 -dinitro-phenol and 4,6-dinitro-2-methylphenols.