Electrode serial

Puacz et al. (1995) developed a catalytic method, based on the iodine-azide reaction, for the determination of hydrogen sulfide in human whole blood. The method involves the generation of hydrogen sulfide in an evolution-absorption apparatus. In addition, the method allows for the determination of sulfide in blood without interference from other sulfur compounds in blood. A detection limit of 4 g/dm3 and a percent recovery of 98-102% were achieved. Although the accuracy and precision of the catalytic method are comparable to those of the ion-selective electrode method, the catalytic method is simpler, faster, and would be advantageous in serial analysis. 

Figure 4.13 — (A) Serially arranged ISEs for the simultaneous determination of sodium, potassium, calcium and chloride ions. (B) Serially and parallelly arranged ISEs for the simultaneous determination of T, Br", Cl and F . WE working electrode PC personal computer Ej-E r, Cr, Br" and F ISEs, respectively C C3 amalgamated-lead columns (1.5 and 2.5 cm long, respectively) AgCl column RE reference electrode PHM pH/mV-meter S sample injection CS carrier stream P pump R chart recorder W waste. (Reproduced from [126] and [127] with permission of Elsevier Science Publishers and Pergamon Press, respectively).

In the last part of the chapter, we have described some efforts toward the modification of the counter electrode with inexpensive and transparent materials. The interest being also related to the possible realization of stacked cells, either serially or in parallel connected, in which two spectrally complementary dyes can work in their optimal absorption region, improving the spectral responsivity of the modules. In these studies, it has been found that osmium complexes as well as... 

To use Equation 20.6 to calculate the fractional concentration change resulting from a diffusion process, one partitions the medium (the solution) into an as yet unspecified number of volume elements of thickness Ax and requires that f(x,t) be uniform within each element. In the simplest case, these elements would form a linear array originating at a planar surface (the electrode) of area A located at x = 0. Therefore, the volume of each element will be A Ax, as represented in Figure 20.1. Each element may be assigned a serial number, J, as indicated in this figure, so that any distance x is given as... 

With regard to assaying the inhibitory activity of extracts electro-chemically, one of the problems of assays using sensors based on cholinesterase was that considerable time, e.g. 30-45 min [46,47], could be needed for the activity of the enzyme electrode to fall below control levels. The time increased as the level of inhibition decreased. Such lengthy assays make any number of serial assays impractical. In previous work [48,49], it had been noted that if sensors were exposed to solution containing inhibitors and then allowed to dry, they could be... 

Dual-electrode detection for CE is much simpler to implement in the microchip format and offers additional sensitivity and selectivity due to the ability to monitor reversible redox reactions as well as help for identifying peaks in complex mixtures. Dual detection with serial gold [90,91] and carbon paste [92], fibre [93] and pyrolysed photoresist [94] working electrodes was reported. 

Potentiometric measurement using a Pt electrode has been employed in a titration (between Cr,072 and Fe(CN)63 ) which was carried out on a PDMS-glass chip. An 11-channel serial dilutor was used to produce the different titrant concentrations, and a chaotic advective mixer was incorporated to facilitate solution mixing [769]. 

The electrochemical TNT sensor was mounted onto the UUV as a separate module, and it serially sent data values to the REMUS UUV. The electrode assembly was mounted on the cone nose of the vehicle and connected to the internal microanalyzer (Fig. 7). Major attention was given to the optimization of variables of the square-wave waveform (including the frequency, amplitude, and potential step) essential for attaining high speed... 

In general, a large serial resistance and an over-small parallel resistance (shunt) tend to reduce the FF. Strategies for reducing the serial resistivity by improving the quality of the Ohmic contact will be discussed. The insertion of very thin polar layers like LiF have been shown to reduce the interface barrier at the cathode in bulk heterojunction solar cells, if they are evaporated between the photoactive material and an A1 electrode [93,94]. 

In all experiments the electrolyte was the highest quality tetra-n-butyl ammonium tetrafluoroborate furnished by Eastman and J.T. Baker, the working electrode was glassy carbon (area 0.31 cm2) polished before each scan, except in film formation studies. The reference electrode was saturated calomel, and the auxiliary electrode was platinum wire. Electrodes and cells were purchased from Princeton Applied Research (PAR). The instrument was a PAR Model 170 Electrochemistry System, Serial No. 16109. 

Another method of spatially resolving variations in impedance involves constructing regular arrays of small cells on a sample surface and performing conventional EIS measurements in them on a serial basis (138). This method does not require any special measurement equipment beyond that needed for conventional EIS measurement. However, as the cell size and working electrode area is reduced, the measured current will be reduced to the point where noise and instrument current resolution become factors. These factors limit how small a cell can be and determine the spatial resolution of the technique. This technique has been used to examine the changes in the EIS response on coil coated galva-... 

The -> impedance of a planar capacitive electrode immersed in a resistive solution conforms to that of a serial R-C circuit. If the geometry of the capacitive electrode is some fractal, then the electrode impedance, Z(o>), is a - CPE, Z = const ( to) n, and the exponent n - depending on the actual form of the fractal - is some function of Df. 

A gold quartz crystal surface can be easily functionalized with an avidin monolayer (Fig. 7.3) that will then allow immobilization of any biotinylated biomolecule through strong avidin-biotin interaction. The only requirement for the development of a successful biosensor device is the availability of biotin-tagged molecules. We have used this strategy to achieve DNA electrode materials without the need for hybridization [44-46]. The dsDNA serial assembly was achieved by first linearizing circular plasmid... 

Figure 20 displays some chromatograms taken from these serial measurements. The flow rates are listed in Table I. If one particular analysis is desired, the electrode height and other parameters (air, for instance)... 

Figure 1 shows only the electrochemical core of a fuel cell. However, a single electrode-electrolyte assembly is not sufficient for electricity generation, since the typical voltage of a single cell is below 1 V. In order to obtain suitable voltages, a number of cells are serially connected. Thus, in addition to the electrochemical components, a fuel cell needs interconnector plates, which connect two electrically adjacent electrochemical units and usually also... 

Kerwin AJ, McLean R, Tegelaar H. A method for the accurate placement of chest electrodes in the taking of serial electrocardiographic tracings. Can Med Assoc J 1960 82 258. 

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