Simultaneous Voltammetric Determination of Benzene, Toluene and Xylenes (BTX) in Water Using a Cathodically Pre-treated Boron-doped Diamond Electrode

An electrochemical method for the simultaneous determination of benzene, toluene and xylenes (BTX) in water was developed using square-wave voltammetry (SWV). The determination of BTX was carried out using a cathodically pre-treated boron-doped diamond electrode (BDD) using 0.1 mol L-1 H2SO4 as supporting electrolyte. In the SWV measurements using the BDD, the oxidation peak potentials of the total xylenes-toluene and toluene-benzene couples, present in ternary mixtures, display separations of about 100 and 200 mV, respectively. The attained detection limits for the simultaneous determination of benzene, toluene and total xylenes were 3.0x10(-7), 8.0x10(-7) and 9.1x10(-7) mol L-1, respectively. The recovery values taken in ternary mixtures of benzene, toluene and total xylenes in aqueous solutions are 98.9 %, 99.2 % and 99.4 %, respectively.