Study of the Effect of Nitrotoluene Sulfonates Impurity on the Kinetic of TNT - Potassium Permanganate Reaction

The oxidation – reduction reaction of trinitrotoluene (TNT) with potassium permanganate solution and its decolorination rate are used as a quality control test in industry to verify the purity of TNT. The impurities such as other derivatives of TNT are due to increasing decolorination rate of potassium permanganate solution. On the other, nitrotoluene sulfonates are usually formed when sodium sulfite is added to TNT. The presence of sodium and sulfur in the TNT bulk is confirmed by using ICP technique. In this research, the kinetic of potassium permanganate reaction with pure TNT and nitrotoluene sulfonates (TNT and sodium sulfite) is studied using the absorption spectrometry in visible region and the rate constants and the reproducibility of the method are measured for determination of nitrotoluene sulfonates amounts. In the optimized concentrations of sulfuric acid (0.6 M) and potassium permanganate (0.6 mM), the results show 1.3 times increasing of reaction rate in the presence of nitrotoluene sulfonate. Introducing a simple, inexpensive and rapid method for quantifying nitrotoluene sulfonates are the advantages of the proposed method.