| Phenolic compounds are widely used in many fields, such as chemical industry, pharmaceutical industry, tanning and dyes. They are important environmental pollutants due to their toxicity to human and difficult to degrade. Although there are many ways to determine the phenolic compounds, it is difficult to find a fast and facile one. As a result, it is necessary to establish a sensitive and selective analytical method to detect phenolic compounds. The work is summarized as follows: First, the electrochemical properties of dihydroxybenzene isomers based on glass carbon electrode were investigated. In 0.1 mol-L-1 HAc-NaAc buffer solution (pH 5.6), the reduction peaks of p - dihydroxybenzene and o - dihydroxybenzene were partly separated by DPV at the GC electrode. By adding the surfactant of cetyl pyridinium chloride (CPC) to enhance the detection sensitivity and using semi-derivative technique to improve the separation, p- DHB and o - DHB have been detected simultaneously. The linear calibration ranges were 1.2 ×10-6 to 1.0×10-4 mol-L-1 for p - DHB and 8.2×10-7 to 1.0×10-7 mol·L-1 for o - DHB, and with detection limits of 3.6×10-7 and 2.4×10-7 mol·L-1, respectively. This method has been applied to the direct determination of DHB isomers in water sample, and the recovery was from 97 to 104%. This is a simple, fast and convenient method. And this also provided a new idea for direct determination of phenolic compounds. Second in the presence of cetyltrimethyl ammonium bromide (CTAB), the electrooxidation of naphthol isomers were studied by cyclic voltammetry on the GC electrode. Two well-defined oxidation peaks at 0.37 V and 0.55V were obtained. By using semi-derivative technique to improve the separation, a-naphthol and 8-naphthol have been detected simultaneously. The linear calibration ranges were 4.3×10-7 to...
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