Detection of chlorophenols in aqueous solution via hydrodynamic channel flow cell voltammetry using a boron-doped diamond electrode

Electroanalysis of the priority pollutant family of chlorophenols is largely unreported in the scientific literature, due mainly to the electrode passivation observed from oxidative products at most solid electrodes. However, the combination of the channel flow cell with a mechanically and chemically robust boron-doped diamond (BDD) as a solid electrode material for the detection of several chlorophenols shows a linear range up to 20 μM. This makes the technique analytically useful over the concentration range in which aquatic chlorophenol pollution requires monitoring. Laser ablation voltammetry using a 532 nm Nd: YAG Laser at 1.6 W cm^-2 produced no significant change in the signal of the current observed and confirmed the lack of any significant electrode passivation for the concentrations studied. Closely similar responses were obtained for 4-chlorophenol, 2-chlorophenol. phenol, 2.4-dichlorophenool and 4-chloro-3-methylphenol suggesting that a "total phenol" concentration could be measured. No interferences were observed when nitrite and sulfite anions were also present in solution even in concentrations higher than those usually found in water samples.