A modified spectrophotometric method for the determination of trace amounts of phenol in water

A modified spectrophotometric method has been developed for the determinati on of phenol in water. The method is based on the reaction between phenol, sodium nitroprusside and hydroxylamine hydrochloride in a buffer medium of pH 10.6-11.8. The linear dynamic range is 0.05-5.0 mg l(-1). The optimum de termination wavelength is at 700 nm. The molar absorptivity is 1.23 x 10(4) mol l(-1) cm(-1). The relative standard deviation of the standard solution of phenol is 1.3% (n = 10, C = 0.5 mg l(-1)). The average recovery of wate r samples spiked with phenol of 2.0 mg l(-1) is 98.8% (n = 10). The relativ e error of standard sample (C = 0.394 +/- 0.003 mg l(-1)) is 2.0%, F values of the statistical analysis show that there is no significant difference b etween the proposed method and the 4-aminoantipyrine method. The crystal of the product of the colored reaction was synthesized. According to its IR s pectrum, Raman spectrum, Mossbauer spectrum and elemental analysis, the com position and structure of the product have been deduced and the mechanism o f the colored reaction has also been investigated. (C) 2000 Elsevier Scienc e B.V. All rights reserved.