Oxidation of trimethoprim by ferrate(VI): kinetics, products, and antibacterial activity

Environ Sci Technol. 2011 Dec 15;45(24):10575-81. doi: 10.1021/es202237g. Epub 2011 Nov 23.


Kinetics, stoichiometry, and products of the oxidation of trimethoprim (TMP), one of the most commonly detected antibacterial agents in surface waters and municipal wastewaters, by ferrate(VI) (Fe(VI)) were determined. The pH dependent second-order rate constants of the reactions of Fe(VI) with TMP were examined using acid-base properties of Fe(VI) and TMP. The kinetics of reactions of diaminopyrimidine (DAP) and trimethoxytoluene (TMT) with Fe(VI) were also determined to understand the reactivity of Fe(VI) with TMP. Oxidation products of the reactions of Fe(VI) with TMP and DAP were identified by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Reaction pathways of oxidation of TMP by Fe(VI) are proposed to demonstrate the cleavage of the TMP molecule to ultimately result in 3,4,5,-trimethoxybenzaldehyde and 2,4-dinitropyrimidine as among the final identified products. The oxidized products mixture exhibited no antibacterial activity against E. coli after complete consumption of TMP. Removal of TMP in the secondary effluent by Fe(VI) was achieved.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Infective Agents, Urinary / analysis
  • Anti-Infective Agents, Urinary / chemistry*
  • Anti-Infective Agents, Urinary / pharmacology
  • Escherichia coli / drug effects
  • Iron / chemistry*
  • Kinetics
  • Models, Chemical
  • Oxidation-Reduction
  • Trimethoprim / analysis
  • Trimethoprim / chemistry*
  • Trimethoprim / pharmacology
  • Waste Disposal, Fluid / methods
  • Water Pollutants, Chemical / analysis
  • Water Pollutants, Chemical / chemistry*
  • Water Pollutants, Chemical / pharmacology


  • Anti-Infective Agents, Urinary
  • Water Pollutants, Chemical
  • ferrate ion
  • Trimethoprim
  • Iron