KINETIC DETERMINATION OF SULFIDE IN WATER AND AIR SAMPLES

A kinetic method for the determination of sulphide based on its inhibi tion of the Pd(LI) catalysed reaction between pyronine G and the hypop hosphite ion is described. The reaction was followed spectrophotometri cally by measuring the decrease in the absorbance at 548 nm. The influ ence of reaction variables and the interfering effect of other substan ces were studied. Under the selected experimental conditions of 5.0 x 10(-5) M pyronine G; pH 3.2; 0.7 mu g ml(-1) Pd(II); 0.4 M H2PO2- and 25 +/- 0.2 degrees C, sulphide was determined in the range 10-200 ng m l(-1). The method was applied to the determination of sulphide in wate r and air samples.