Analytical Sciences

Abstract − Analytical Sciences, 17(3), 435 (2001).

Kinetic Spectrophotometric Determination of Thiocyanate Based on Its Inhibitory Effect on the Oxidation of Methyl Red by Bromate
Jahanbakhsh GHASEMI,*  Reza AMINI,* and Abbas AFKHAMI**
*Department of Chemistry, Razi University, Kermanshah, Iran
**Department of Chemistry, Bu-Ali-Sina University, Hamadan, Iran
A kinetic spectrophotometric method for measuring thiocyanate is described. The proposed method is based on the inhibitory effect of thiocyanate on the oxidation of Methyl Red by bromate in the presence of nitrite, which was monitored at 520 nm. The variables affecting the rate of the reaction were investigated and the optimum conditions were established. Thiocyanate can be measured in the range of 0.05 - 1.1 ug ml-1 with a detection limit of 0.025 ug ml-1. This method has been used to determine trace thiocyanate in urine and tap water samples.