In situ sampling system

The nitrogen associated to the particulate matter collected by filtration [36,160,161], by sediment traps or by in situ sampling systems [162-164] is commonly determined using the high-temperature combustion gas chromatography. 

Table 1 summarizes several of the experimental methods discussed in this chapter. A need exists for new or revised methods for transport experimentation, particularly for therapeutic proteins or peptides in polymeric systems. An important criterion for the new or revised methods includes in situ sampling using micro techniques which simultaneously sample, separate, and analyze the sample. For example, capillary zone electrophoresis provides a micro technique with high separation resolution and the potential to measure the mobilities and diffusion coefficients of the diffusant in the presence of a polymer. Combining the separation and analytical components adds considerable power and versatility to the method. In addition, up-to-date separation instrumentation is computer-driven, so that methods development is optimized, data are acquired according to a predetermined program, and data analysis is facilitated. 

Diffuse reflectance FTIR (DRIFT) spectra were recorded on a Bio-Rad FTIR spectrometer (EXCALIBUR FTS3000). A high-temperature cell was attached to a flow system that allows in-situ sample treatment, adsorption and desorption of probe molecules at different temperatures. 

Figure 7.4 STM chamber in situ sample heating system.

The marked advantage of an in situ detection system is that it does not ingest the molecules hence it does not disturb the area, does not require as close approach to an explosive device, and it should produce a faster response time than ingesting systems. The disadvantage of in situ systems is also that they do not ingest the molecules hence they have no means of concentrating the sample... 

The data collection system consists of a photodiode for each interferometer, an amplifier, A->D board [Metrabyte], and a personal computer for collecting the data in real time. With the exception of the sample and reference mirrors located in the reactor, all of the other components for measuring the sample strains are external to the reactor. Thus, it is not necessary to disturb the sample in order to make these in-situ sample strain measurements. 

A Multiple-Unit Large-Volume In Situ Filtration System for Sampling Oceanic Particulate Matter in Mesoscale Environments... 

Figure 5.5 Time series of interstitial water profiles at an intertidal site in the Wash (UK), near to the major riverine discharge, after the tide has ebbed. The inventory of nitrate in the interstitial water decreases with time due to rapid denitrification. The interstitial water profiles are collected using an in-situ sipping system consisting of porous probes inserted at fixed depths in the sediment from which water samples are removed by applying a vacuum. Samples are preserved using mercuric chloride and returned to the laboratory for colorimetric analysis.

The flow analyser is well suited for handling aqueous samples, which are directly inserted into the manifold by taking advantage of loop-based or time-based sample introduction. Due to the portability, ruggedness, low power requirement and low maintenance requirement inherent to the unsegmented flow systems, specific approaches for in situ sample collection and handling have been proposed. 

Only a limited amount of work on high materials has been performed in the UHV environment. However, a few references to UHV design are included [6.44-6.51]. A few commercial instruments are available either as a complete system (JEOL, for example) or as an add-on to a custom UHV chamber containing other characterization techniques and/or in situ sample preparation (cleaning, annealing, cleaving, pealing) or film deposition capabilities. 

Schematic diagram of two methods of the stationary type of seabed, remote in situ testing system. (After Richards, A.F., and Zuidberg, H.M., Sampling and in situ geotechnical investigations offehore. In Marine Geotechnology and Nearshore/Offshore S tructures, STP 923, Chaney, R.C., and Fang, H.-Y., eds., ASTM, Philadelphia, PA, 51-73,1986. Reprinted with permission. Copyright ASTM.)...

M.P. Dudukovic and P.L. Mills, Challenges inReaction Engineering Practice of Heterogeneous Catalytic Systems Claudia Diehm, Hiisyein Karadeniz, Canan Karakaya, Matthias Hettel, and Obf Deutschmann, Spatial Resolution of Species and Temperature Profiles in Catalytic Reactofs In Situ Sampling Techniques and CFD... 

Traditional adsorption preconcentration techniques are based aroimd the passage of filtered (and sometimes acidified or otherwise pretreated) water through a column of adsorbent. After passage of the sample the compounds of interest are eluted with an appropriate solvent or solvent mixture. Such techniques can be laboratory based, in situ (pumped systems or, more rarely, in passive towed units), or, in more recent systems, can be used in online applications. 

In situ sampling/filtration/extraction systems offer the most favourable conditions for accurate determinations of organic trace compounds in seawater. 

The Kiel in situ pump system (KISP) for filtration and extraction of trace organics at the depth of sampling Petrick et al, 1996) is suitable for volumes of up to 2000 L or more (depending on particle concentration) and depths in excess of 6000 m. Sufficient amounts of PAH and CB may thus be collected in open-ocean waters to allow their analytical determination at concentration levels around or below 0.01 pg/L. The sampler is depicted in Fig. 22-1 (technical details can be found in Chapter 2). 

The sample passes through the GFF filter (300 mm ID, 0.5 i,m pore size), PUFP (100 mm ID, 100 mm height), and back-up PUFP (100 mm ID, 100 mm height). The system design makes it possible to sample up to several cubic meters of water at the flow rate of 1-2 L/min ( = 60-120 L/h = 1440-2880 L/day). The in situ preconcentration system was applied to several water samples 100-200 L and 1500-2000 L of river and tap water samples were collected, respectively. 

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