An Electrode Immobilized in a Graphite Matrix with Ion Pair Complex for the Determination of Pentachlorophenol

A simple, precise, rapid and low-cost potentiometric method for the determination of pentachlorophenol is proposed. A new pentachlorophenol-sensitive electrode was constructed by incorporating the pentachlorophenol ion pair complex with rhodamine 6G into graphite matrix. The electrode exhibited a linear response over the concentration range of 1×10–5–5×10–2 mol/L, a detection limit of 1.7×10–6 (5.2×10 5) mol/L with a Nernstian slope of 41±1 (68±1) mV/decade. The working pH range is 7.5–10.5. The electrode is easily constructed, has fast response time (3–10 s) and can be used for the period of six months without any considerable deterioration. The proposed sensor displays good sensitivity for pentachlorophenol.