Chiang Mai Journal of Science

      Proposed study described a new approach for the identifi cation of three isomers of benzyloxyphenol (BLP) i.e. 2-BLP, 3-BLP, and 4-BLP on their perturbation effects by using a novel Belousov-Zhabotinsky (BZ) oscillating system. In such a system, typical oscillating profi le was achieved due to the oxidation of malic acid (substrate) by NaBrO₃ in the presence of tetra-azamacrocyclic Cu-complex catalyst ([CuL](ClO₄)₂) in an acidic medium. Ligand “L” in the complex is 5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraeazacyclotetradeca-4,11-diene. Perturbation experiments were carried out by adding identical amounts of analytes into the active BZ system. As a result, quite different responses were achieved which can be accredited to propose a new identifi cation technique based on the oscillation system. Concisely, 2-BLP produced a shorter inhibition time (t_in) with a small regenerated oscillation amplitude (A) while 3-BLP almost suppressed oscillation (longer t_in) with a small regeneration of A. As compared to 2-BLP and 3-BLP, the 4-BLP initiated higher regeneration of A but produce larger t_in from 2-BLP and shorter than 3-BLP. Thus, these three isomers were distinguished. Through cyclic voltammetry, redox reactions were confi rmed between the additives and NaBrO₃ while the oxidized products (quinones) from these isomers were identifi ed by Ultraviolet (UV) and InfraRed (IR) spectroscopies. The perturbation reaction mechanism is justifi ed on the outcomes of the above-mentioned techniques and the FKN mechanism.