A modified potentiometric method for the estimation of phenol in aqueous systems

A modified potentiometric titration is proposed for the estimation of pheno l in aqueous systems. The method is evolved on the basis of a critical depe ndence of pH on log V rather than simple V, as used in conventional potenti ometric titrations. The method incorporates titrants in a concentration ran ge several orders of magnitude greater than that of phenol in the aqueous p hase. Derivative potentiometric curves so obtained provide a clear expositi on of the equivalence point and the overall error is found to be between +/ -1.0 and 1.5%. The range of phenol concentration investigated was from 10(- 2) to 10(-3) M. and that of sodium hydroxide used as the titrant from 10(-1 ) to 4.0 M. The maximized titrant concentrations were found to be helpful i n controlling the dilution problem during titration. The lowest detection l imit achieved was 50 mg phenol/L and the method is well-suited to direct aq ueous phase municipal sewage, home effluents and industrial discharges for phenol determination.