A low cost method which based on the reaction of Pentachlorophenol (PCP) with concentrated nitric acid to form chloranil, which liberates iodine with potassium iodide, is described. The liberated iodine bleaches the violet colour of AZURE-B which is measure at 650nm. Beer's law is obeyed over the concentration range of 1-10 µg of PCP in final solution volume of 25 ml (0.04 - 0.4 ppm). The apparent molar absorptivity and Sandell's sensitivity were found to be 5.28 x 105 l mol-1 cm-1 and 51x 10-5 µg cm-2. The method has been satisfactorily applied to the determination of PCP in air, water, plant material, textile effluent and biological samples.
