ISSN 1017-2548(Print)
ISSN 2234-8530(Online)
Volume 38, Number 12
JKCSEZ 38(12)
December 20, 1994 

An indirect spectrophotometric method, presumably heretofore unmentioned, for the rapid determination of COD in the presence of chloride of high concentration is described. The alkaline sample is refluxed to react with a definite amount of permanganate, present in excess. A photometric measurement at 535 nm for the extent of the fading of the permanganate color after refluxing completes the procedure. The optimum conditions which give the absorbance-concentration plot the maximum linearity and slope in the range of 0∼5 ppm COD are as follows: reflux at 100℃ for 10 min in the presence of 0.15 mM permanganate and 0.2% NaOH with a sample size of 5 ml. An overall running time was less than 15 min. The t-test reveals that the proposed method is not significantly different from the official method.