Catalytic spectrophotometric determination of trace phenol in waste water with phenol-potassium bromate-rhodamine 6G system

A rapid and convenient catalytic spectrophotometric method for the determination of trace phenol was established, on the basis of the catalytic effect of phenol on the discoloring reaction of rhodamine 6G and potassium bromate in 0.20 mol/L sulfuric acid medium. A new purple red dye,of which maxmium absorption peak lied at 542 nm was formed in the catalytic reaction and the increase in absorbance, ΔA was linear with the concentration range of 0.02-0.80 mg/L for phenol at 542 nm.The apparent activation energy of catalytic reaction was 112 kJ/mol . Common cations and anions, p-phenol and m-phenol do not interfere with the determination. The method has been applied to the determination of phenol in waste water with satisfactory results.