Kinetic studies generation collection

A feature of SECM is the quantitative theory available based on reaction-diffusion models (Chapter 5). The SECM may be used for kinetic studies in either the feedback or generation-collection modes. These two possibilities are described below from the point of view of studying immobilized enzyme kinetics. 

Fernandez JL, Bard AJ (2004) Scanning electrochemical microscopy 50. Kinetic study of electrode reactions by the tip generation-substrate collection mode. Anal Chem 76(8) 2281-2289. doi 10.1021/ ac035518a... 

The development of SECM, which began in the late 1980s, is mainly credited to A. Bard and his coworkers who first described the technique, coined its name, and also developed the early modes of its operation, namely the feedback and the generation-collection modes, which will be described later. In the course of its nearly 30 years of existence, SECM has established itself as the tool of choice for studying spatially resolved local electrochemical reactivity of surfaces, including the quantitative study of the kinetics of both electrochemical and chemical reactions from microscopic to submicroscopic scales [2, 7]. Indeed, the ability of SECM to... 

Fig. 6 Concentration-time profile of antidotal atropine and its enantiomers S- and / -hyoscyamine in plasma of an in vivo swine study. Swine were topically exposed to the nerve agent VR (302 pg/ kg, t0) followed by administration of atropine sulphate (30 pg/kg) and the reactivating oxime HI 6 (12.8 mg/kg) via three i.m. injections into the rear leg at 30 (I), 180 (II) and 330 min (III). Blood samples were collected at distinct time points to generate EDTA plasma. Maximum concentrations were found 4 min after drug administration each. No differences of S- and R-Hyo concentrations were evident underlining similar elimination kinetics for both enantiomers. Data are mean and SD from duplicate measurement using the enantioselective LC-MS/MS approach of John et al. [47,49]. Black circles, total hyo grey circles, S-hyo grey triangles, R-hyo...

To test the ECD hypothesis, E. C. M. Chen measured the temperature dependence of the molar response. This entailed a detailed study of all parameters associated with the pulse sampling method. For these molecules the most important reactions were postulated to be electron generation and collection, electron and ion recombination, electron attachment and detachment. It was discovered that the simple thermodynamic model was not applicable and that a kinetic model was necessary to explain the change in temperature dependence. If we assume a steady state exists, an expression can be obtained that relates the ECD molar response to kinetic rate constants for the above reactions [24, 25],... 

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