Flow injection potentiometric determination of chlorpromazine

New chlorpromazine selective electrodes with a tubular arrangement and no internal reference solution are proposed. Selective membranes are of poly(vinyl chloride) (PVC) with the tetraphenylborate·chlorpromazine (TPB·CPZ) ion-exchanger dissolved in o-nitrophenyl octyl ether (oNPOE). Analytical features of the electrodes were evaluated on a single-channel flow assembly having 500 μl injection volumes and flow-rates of 4.5 ml min−1. For a carrier solution of 3.3 × 10−3 M in sodium sulphate, Nernstian response was observed over the concentration range 1.0 × 10−5 to 1.0 × 10−2 M. Average slopes were about 59 mV decade−1 and squared correlation coefficients were >0.9984. Slight hiper-Nernstian behaviour was observed in buffer solutions of 4.4 pH; average slopes were of 62.06 mV decade−1. The electrode displayed a good selectivity for CPZ, with respect to, several foreign inorganic and organic species.The selective electrodes were successfully applied to the analysis of pure solutions and pharmaceutical preparations. Proposed method allows the analysis of 84 samples h−1, producing wastewaters of low toxicity. The proposed method offers the advantage of simplicity, accuracy, applicability to coloured and turbid samples, and automation feasibility.