Abstract

The chloride ion (Cl-) is very important to both human and animal health, and directly impacts on the natural environment. This paper proposes a simple, accurate, sensitive and selective flow injection catalytic kinetic spectrophotometric method for the rapid determination of chloride ion in tannery effluent. In acidic media and with heat, the reaction of indigo carmine and potassium bromate is catalysed by the chloride ion. The absorbance of this reaction solution was recorded at 610nm. Chemical factors and FIA variables affecting the system were also discussed.

The linear concentration range of the calibration curve was from 0.2-42.0mg l-1 of standard solutions. The relative standard deviation was 0.88% for 28.0mg l-1 chloride ion (n = 9), and the detection limit was 0.009mg l-1 calculated from three times the average background noise. This method, which is suitable for automatic and continuous analysis, has been successfully applied to the determination of chloride ion in tannery effluent.