The in situ environment

E.M. Stuve, A. Krasnopoler, and D.E. Sauer, Relating the in-situ, ex-situ, and non-situ environments in surface electrochemistry, Surf. Sci. 335, 177-185 (1995). 

The second approach is to study real catalysts with in situ techniques such as infrared and Mossbauer spectroscopy, EXAFS and XRD, under reaction conditions, or, as is more often done, under a controlled environment after quenching of the reaction. The in situ techniques, however, are not sufficiently surface specific to yield the desired atom-by-atom characterization of the surface. At best they determine the composition of the particles. 

Fuchs, B. M. Wallner, G. Beisker, W. Schwippl, I. Ludwig, W. Amann, R. Flow cytometric analysis of the in situ accessibility of Escherichia coli 16S rRNA for fluorescently labeled oligonucleotide probes. Appl. Environ. Microbiol. 1998, 64, 4973 1982. 

In contrast to other analytical methods, ion-selective electrodes respond to an ion activity, not concentration, which makes them especially attractive for clinical applications as health disorders are usually correlated to ion activity. While most ISEs are used in vitro, the possibility to perform measurements in vivo and continuously with implanted sensors could arm a physician with a valuable diagnostic tool. In-vivo detection is still a challenge, as sensors must meet two strict requirements first, minimally perturb the in-vivo environment, which could be problematic due to injuries and inflammation often created by an implanted sensor and also due to leaching of sensing materials second, the sensor must not be susceptible to this environment, and effects of protein adsorption, cell adhesion, and extraction of lipophilic species on a sensor response must be diminished [13], Nevertheless, direct electrolyte measurements in situ in rabbit muscles and in a porcine beating heart were successfully performed with microfabricated sensor arrays [18],... 

D. Ganser, M. Burgdorf, R. Losch (2001) A novel approach to the in situ measurement of oxygen concentrations in the sapwood of woody plants. Plant, Cell and Environment, 24 1055-1064... 

Collection of in situ XAS data using a single cell fuel cell avoids problems associated with bubble formation found in liquid electrolytes as well as questions regarding the influence of adsorption of ions from the supporting electrolyte. However, the in situ study of membrane electrode assemblies (MEAs) in a fuel cell environment using transmission... 

Elshahed, M.S., Gieg, E.M., Mclnerney, M.L., and Suflita, J.M. Signature metabolites attesting to the in situ attenuation of alkylbenzenes in anaerobic environments. Environ. Sci. Technoi, 35(4) 682-689, 2001. 

Cement-based stabiUzation/solidification (S/S) is a technology for the in situ or ex situ treatment of hazardous wastes and hazardous waste sites. It is a process that uses cement and other additives or processes to physically and/or chemically immobilize the hazardous constituents of contaminated soils, sludges, sediments, or liquid wastes. The objective is to prevent the migration of contaminants in the environment by forming a solid mass. 

The in situ nature of this treatment also minimizes potential exposure to humans and the environment. Ex situ options like excavation require repeated worker handhng of the contaminated soil and increased opportunity for volatilization of contaminants (leading to off-site contamination). The off-gas stream generated as part of the SPSH process can be treated using conventional off-gas treatment technologies such as catalytic oxidation, thermal oxidation, condensation, and granular activated carbon (GAC). 

Over recent years, the electrochlorination of a wide range of substrates has been reported. The direct halogenation of benzene has been studied at Pt and Rh electrodes and the in situ spectro-electrochemical monitoring of the process with confocal microprobe Raman methods allowed optimization of the reaction conditions [80]. Toluene has been chlorinated at DSAs and the kinetics of this process have been explored in detail [81]. The electrochlorination of 1,4-dimethoxy-2-tert-butylbenzene has been reported in CCI4 and in acetonitrile environments [82]. A difference in mechanism has been proposed to explain the observation of l,4-dimethoxy-2-tert-butyl-5-chlorobenzene and l,4-dimethoxy-2-tert-butyl-6-chlorobenzene, respectively, as the main products. Succinimide is electrochlo-rinated to give A -chlorosuccinimide at platinum electrodes, but the process has been reported to be relatively inefficient due to side reactions (when compared... 

Most asymmetric catalyses are termolecular reactions. To obtain a sufficient asymmetric bias, the reactant and/or substrate must be placed in a chiral environment induced by the catalyst. Perhaps one of the most reliable mechanisms for transmitting stereochemical information is the in situ formation of reactive intermediates in which the chiral catalyst and reactant are covalently bound. Under some conditions, the inter-... 

As life-cycle qualification activities move to the in situ operating environment a methodical approach for the site calibration of control and monitoring instrumentation is needed to provide suitable calibration and any associated records for the loop instrumentation and regulating devices on critical parameter duty. 

An early paper on the use of ATR for the in - situ monitoring of the adsorption of AOT from heptane and water solutions utilized the intensity of the 0=0 band (near 1740 cm1) and the sulfonate band (1045 cm1) for construction of adsorption isotherms. In addition, the utility of detailed examination of the shifts in the sulfonate band frequency for assessing the headgroup environment in adsorbed layers was discussed (115). 

Dunn, R.J.K., PR. Teasdale, J. Wamken, and J.M. Arthur. 2007. Evaluation of the in situ, time-integrated DGT technique by monitoring changes in heavy metal concentrations in estuarine waters. Environ, Pollut. 148 213-220. 

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