title: Ultratrace kinetic measurements of the reduction of methylene blue.
abstract: 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.
authors.affiliation: Department of Chemistry, Stanford University, Stanford, California 94305-5080, USA.
authors.forename: Alexander J
authors.initials: AJ
authors.lastname: Hallock
authors.forename: Elena S F
authors.initials: ES
authors.lastname: Berman
authors.forename: Richard N
authors.initials: RN
authors.lastname: Zare
mesh_terms: 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
chemical_list: D000097:Acetonitriles; C011010:hydromethylthionine; D001205:Ascorbic Acid; D008751:Methylene Blue; C032159:acetonitrile