A new extraction spectrophotometric method for the determination of phenol in water

The product of the reaction among phenol, sodium nitroprusside and hydroxylamine hydrochloride in an alkaline solution can be extracted by chloroform in the presence of cetylpyridinium bromide (CPB), on the basis of which a new extraction spectrophotometric method for the determination of phenol in water is developed. The optimum determination wavelength is 720 nm. The molar absorptivity is 1.05 X 10(5) mol(-1) . L . cm(-1) and the detection limit is 4.0 mu g/L. For 30.0 and 60.0 mu g/L standard solutions, the relative standard deviations are 4.5% and 2.2%, respectively (n = 6). F values of the statistical analysis show that there is no notable difference between the proposed method and 4-AAP method. The results of the standard addition method for the natural water sampled are satisfactory.