A kinetic method for the determination of thiourea by its catalytic effect in micellar media

Spectrochim Acta A Mol Biomol Spectrosc. 2009 Mar;72(2):327-31. doi: 10.1016/j.saa.2008.09.029. Epub 2008 Oct 19.


A highly sensitive, selective and simple kinetic method was developed for the determination of trace levels of thiourea based on its catalytic effect on the oxidation of janus green in phosphoric acid media and presence of Triton X-100 surfactant without any separation and pre-concentration steps. The reaction was monitored spectrophotometrically by tracing the formation of the green-colored oxidized product of janus green at 617 nm within 15 min of mixing the reagents. The effect of some factors on the reaction speed was investigated. Following the recommended procedure, thiourea could be determined with linear calibration graph in 0.03-10.00 microg/ml range. The detection limit of the proposed method is 0.02 microg/ml. Most of foreign species do not interfere with the determination. The high sensitivity and selectivity of the proposed method allowed its successful application to fruit juice and industrial waste water.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Azo Compounds / chemistry
  • Beverages
  • Biological Assay / methods*
  • Catalysis
  • Detergents / chemistry
  • Fruit / chemistry
  • Humans
  • Indicators and Reagents / analysis*
  • Industrial Waste
  • Micelles*
  • Molecular Structure
  • Octoxynol / chemistry
  • Oxidation-Reduction
  • Phosphoric Acids / chemistry
  • Sensitivity and Specificity
  • Sewage / chemistry
  • Thiourea / analysis*


  • Azo Compounds
  • Detergents
  • Indicators and Reagents
  • Industrial Waste
  • Micelles
  • Phosphoric Acids
  • Sewage
  • Octoxynol
  • janus green
  • phosphoric acid
  • Thiourea