Determination of phenol in water by pervaporation–flow injection analysis Original Research Article

A pervaporation–flow injection method for the determination of phenol in aqueous samples is described. The method involves sample injection into a concentrated sodium chloride (25 wt.%) donor stream at pH 2 and stopping the flow of the acceptor stream containing 0.1 M KNO3 and 0.01 M NaOH in the acceptor chamber of the pervaporation unit for 12 min. This period allows the completion of phenol transfer from the headspace of the donor chamber of the pervaporation unit through the membrane into the static solution in the acceptor chamber. After restarting the flow through the acceptor chamber the phenol concentration is detected amperometrically at a glassy carbon electrode set at +0.6 V. At 20°C the linear detection range was found to be 1–50 mg l−1 with R.S.D. varying between 1 and 4% for n=3. The detection limit and sample throughput were determined as 0.9 mg l−1 and 5 h−1, respectively. Excellent agreement with the standard 4-aminoantipyrine (4-AAP) method was observed when validating the method with lake samples containing suspension and spiked with phenol.