Ultratrace kinetic measurements of the reduction of methylene blue.
The kinetics of methylene blue reduction by ascorbic acid in acetonitrile was investigated by cavity ring-down spectroscopy. Because of our high sensitivity we were able to use very low concentrations (1-10 nM) of the dye. Under these conditions, we observed a second-order loss of dye as well as a competing back reaction with dissolved oxygen. The use of an inexpensive diode laser and a relatively simple setup should make ultratrace kinetic studies more accessible.
Hallock
Alexander J
AJ
Department of Chemistry, Stanford University, Stanford, California 94305-5080, USA.
Berman
Elena S F
ES
Zare
Richard N
RN
D000097:Acetonitriles / Q000737:chemistry; D001205:Ascorbic Acid / Q000737:chemistry; D007700:Kinetics; D007834:Lasers; D008751:Methylene Blue / Q000031:analogs & derivatives* / Q000737:chemistry*; D055095:Optics and Photonics / Q000295:instrumentation; D010084:Oxidation-Reduction; D012680:Sensitivity and Specificity; D013057:Spectrum Analysis
D000097:Acetonitriles; C011010:hydromethylthionine; D001205:Ascorbic Acid; D008751:Methylene Blue; C032159:acetonitrile