Plating in-situ

Elorence, T.M. Anodic stripping voltammetry with a glassy carbon electrode mercury-plated in situ. J. Electroanal. Chem. 1970, 27, 273-281. 

The degradation of chemical systems under the repeated pulsing required by TCSPC implies that one must look for ways to use the cyclic pulse sequence to reinitialize the chemical system in each observation cycle. We have done this in our studies of platinum electrodes to restore a clean, reduced surface in each cycle. To expand the scope of the chemistry that can be studied reliably, we have begun to consider other means that can allow similar restoration of desired conditions on short timescales. Mercury electrodes are attractive, because they can be partially stripped and plated in situ and because one can often expel adsorbates by simply polarizing the electrode to sufficiently extreme potentials. 

Finally, a thin chromium deposit was plated in situ on a tungsten substrate, then chronopotentiograms were recorded, the analysis of which showed that Cr(II) species was adsorbed, and that adsorbed and dissolved Cr(II) species participated in the reduction process. No adsorption was demonstrated on a vitreous carbon electrode. Cyclic voltammetry was then used at gold, copper, nickel, vitreous carbon and tungsten electrodes (Figure 19). 

Self-baked carbon electrodes are those whose shapes are formed in situ (33). The carbonaceous mixture is placed into a hoUow tube-shaped metal casing. The upper end receives the unbaked mixture as a soHd block, small particles, or warm plastic paste. The casing contains inwardly-projecting longitudinal perforated fins that become surrounded by baked carbon as the casing is incrementally moved downward and through the contact plates. Casing and carbon are consumed in this furnace. 

Prechromatographic dansylation has the advantage that chromatography separates excess reagent and also the fluorescent by-products (e g dansyl hydroxide) from the reaction products of the substances to be determined In the case of postchromatographic dansylation the whole of the plate baekground fluoresees blue, so that in situ analysis is made more diflicult... 

In situ quantitation Fluorimetric analysis was made with long-wavelength UV light (2exc = 365 nm, X(, > 430 nm). The detection limit on HPTLC plates that were analyzed in a moist state was 25 ng cholesterol per chromatogram zone (Fig. 1). 

In situ quantitation The plate was scanned with visible light (2 = 520 nm) in the reflectance mode (Fig. 1). 

Ring closure of 2, which can be generated in situ by the action of sodium hydroxide on the iminium perchlorate 1, with aqueous ammonia furnishes cyclopenta[c]azepine (3) as violet plates.4... 

Carbon dioxide has been proposed as an additive to improve the performance of lithium batteries [60]. Aurbach et al. [61] studied the film formed on lithium in electrolytes saturated with C02, and using in situ FTIR found that Li2C03 is a major surface species. This means that the formation of a stable Li2C03 film on the lithium surface may improve cyclability [62], Osaka and co-workers [63] also studied the dependence of the lithium efficiency on the plating substrate in LiC104-PC. The addition of C02 resulted in an increase in the efficiency when the substrate was Ni or Ti, but no effect was observed with Ag or Cu substrates. 

The hydrogen gas was later" shown to originate from the formaldehyde, not the water. Instead of cumbersome and slow ex situ weighing, Wiese and Weil measured the plating rate in situ with a quartz microbalance. They connected the electrode to a potentiostat to keep it at the plating... 

In situ loading during the chromatographic development. By this method a continuous gradient of the hquid stationary phase is created on the PLC layer in the direction of the mobile phase flow. This is achieved by developing the plate with a suitable multieomponent solvent system. 

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