Redox measurements

Redox measurements (see Table VIII) on several isoindole derivatives indicate that this system should be particularly susceptible to reduction. In practice, reduction of isoindoles (and, presumably, also... 

Criterion C3 internal redox measure oxygen balance... 

Patrick WH, Gambrell RP, Faulkner SP. Redox measurements of soil. In Sparks DL, editor. Methods of Soil Analysis, Part 3 Chemical Methods, 3rd Ed. Madison SSSA 1996. pp. 1255-1273. 

Titrations can often be conveniently followed potentiometrically and in many cases it is not the actual value of the electrode potential that is important but the pattern of changing potential as the composition of the solution varies - pH and redox measurements are particularly well suited to such methods. In many instances the equivalence point will be indicated by a significant change in potential (Figure 4.6) but sometimes the change at the equivalence point is difficult to... 

Peiffer, S., O. Klemm, K. Pecher, and R. Hollerung. 1992. Redox measurements in aqueous solutions—A theoretical approach to data interpretation based on electrode kinetics. J. Contam. Hydrol. 10, 1-18. 

Pt electrodes, respectively (5). Voltage readings from the Pt electrode in the Np suspensions appeared stable within 15 minutes The redox measurements were converted to pe values [pe 16.9 Eh (in volts) at 25°C] because it is convenient to discuss the redox potential of an aqueous solution in terms of the pe (defined as -log Q of the electron activity)(8). 

Potentiometric redox measurements are often performed in nonaqueous or mixed-solvent media. For such solvents various potentiometric sensors have been developed, which, under rigorously controlled conditions, give a Nemstian response over a wide ranges of activities, particularly in buffered solutions. There are some experimental limitations, such as with solvent purification and handling or use of a reference electrode without salt bridges, but there also ate important advantages. Solutes may be more soluble in such media, and redox... 

Munoz 1994). Furthermore the electrode is highly susceptible to contamination effects. While contaminations of a platinum electrode can be disposed of managed, thermodynamic disequilibrium and low concentrations can not. Therefore redox measurements should be aborted after 1 hour if no steady value is reached. The statement derived from the measurement in that case is, that the water is redox species are not in thermodynamical redox equilibrium with the platinum electrode. 

Kokholm, G. 1977. Redox Measurements Their Theory and Technique. ST40, Radiometer A/S Emdrupvej 72 DK-2400, Copenhagen NV, Denmark. 

Figure 6.177 Two-wire transmitter for pH/redox or conductivity measurements. pH-measuring range pH 2.00—16.00 Resolution pH 0.01 Automatic temperature compensating range -20°C—H50°C Redox measuring range -1500—r1500mV Resolution 1 mV Conductivity measuring range 0-2000 mS/cm ...

Camera 119] discussed the control of the safety of nitration of pentaery-thritol with nitric acid by Redox measurement as described in Chapter X. 

Other electrodes which have been examined are as follows graphite electrodes, simple Ag, AgCl reference electrodes (Farrell etal. 1991) microelectrodes constructed from micropipets (Pang Zhang 1998 Shaikh etal. 1985). James and Bartell (2000) also list several general reviews and examples of redox measurements. 

The redox potential, like the pH, is an intensity measurement. In theory, it measures the availability rather than the quantity of electrons. Because the redox potential is governed by the potential rate of electron donation versus the rate of electron acceptance, however, it is also a crude estimate of the number of electron donors (reducing agents) present. The qualitative nature of redox measurements has discouraged their use. Redox measurements, however, are used frequently in wastewater treatment to indicate the extent of treatment necessary. 

What electrochemical properties for redox measurements would the ideal electrode have ... 

Johnson, B., Hydroperoxide determinations from Hf- Redox Measurements , Courtaulds Coatings Tech. Report, (1993) (c). 

Measurement of Trans-membrane Potential. For a constant bias potential, negligible current flows through the insulator on the semiconductor chip, so that there is no steady state potential across Rm- The potential across the chip is y - Vm. If in the absence of the membrane an photocurrent inflection point potential was measured at S = pip/ then in the presence of the membrane it will shift positive by the value of the trans-membrane potential as indicated by Equation 3. Measuring Vm is clearly analogous to using the sensor to make pH or redox measurements. 

In conjunction with in vitro redox measurements on BChl and BPh monomers, the measurement of the free energy gap of a mutant allows us to attempt an extrapolation of the location of the CT state in the wild type RC. Solution measurements indicate that the difference in redox potential between a BChl and a BPh is on the order of 0.2-... 

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