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Collection of effluents

The second interface design that was developed for use with yu-SEC-CZE used the internal rotor of a valve for the collection of effluent from the SEC microcolumn. The volume collected was reduced to 500 nL, which increased the resolution when compared to the valve-loop interface (20). However, a fixed volume again presented the same restrictions on the SEC and CZE operating parameters. An entirely different approach to the interface design was necessary to optimize the conditions in both of the microcolumns. [Pg.206]

Principles and Characteristics Multidimensional gas chromatography (MDGC) is widely used, due to the mobile-phase compatibility between the primary and secondary separating systems, which allows relatively simple coupling with less-complicated interfaces. In its simplest form, 2DGC can be carried out in the off-line mode. The most elementary procedure involves manual collection of effluent from a column, followed by reinjection into another column of a different selectivity (e.g. from an apolar to a polar column). Selecting proper GC-column combinations is critical. In on-line mode, the interface in MDGC must provide for the quantitative transfer of the effluent from one column... [Pg.548]

Collection of effluent fractions is followed by their analyses using the detection devices based on a physical property such as refractive index, condictivity, ultra violet or visible absorption. [Pg.91]

A small (25-kg), portable apheresis system, available in 1993, is designed to meet a wide variety of blood cell separation needs. The role of the apheresis system is to control the behavior, separation, and collection of blood components from the bowl while maintaining maximum donor safety. The system controls the flow rates of blood and components through variable pump speeds. It directs the flow of components out of the bowl, by fully automatic opening and closing of valves based on the output of the system sensors. The system monitors the separation of blood components in the bowl by an optics system that aims at the shoulder of the bowl. A sensor on the effluent line monitors the flow of components out of the bowl. [Pg.523]

Accepting that the cryofocussing/remobilization process is both effective in the collection of discrete sections of the effluent from column 1, and very rapid in reinjection to column 2, we can now propose a number of ways of using the LMCS device in multidimensional gas chromatography modes. [Pg.87]

Fill a 250 mL separatory funnel with ca 0.25M sodium sulphate solution. Allow this solution to drip into the column at a rate of about 2 mL per minute, and collect the effluent in a 500 mL conical flask. When all the solution has passed through the column, titrate the effluent with standard 0.1 M sodium hydroxide using phenolphthalein as indicator. [Pg.207]

Weigh out accurately about 0.10 g of analytical grade sodium chloride and about 0.20 g of potassium bromide, dissolve the mixture in about 2.0 mL of water and transfer quantitatively to the top of the column with the aid of 0.3 M sodium nitrate. Pass 0.3 M sodium nitrate through the column at a flow rate of about 1 mL per minute and collect the effluent in 10 mL fractions. Transfer each fraction in turn to a conical flask, dilute with an equal volume of water, add 2 drops of 0.2M potassium chromate solution and titrate with standard 0.02M silver nitrate. [Pg.209]

There are two general types of multidimensional chromatography separation schemes those in which the effluent from one column flows directly on to a second column at some time during the experiment, and those in which some type of trap exists between the two columns to decouple them (off-line mode). The purpose of a trap is often to allow collection of a fixed eluate volume to reconcentrate the analyte zone prior to the second separation step, or to allow a changeover from one solvent system to another. The use of offline multidimensional techniques (conventional sample cleanup) with incompatible mobile phases, is common in the literature, and replacing these procedures with automated on-line multidimensional separations will require continuous development efforts. [Pg.546]

SFC-TLC is largely unexplored. Stahl [927] developed a device for supercritical fluid extraction with deposition of the fluid extracts on a moving TLC plate. Wunsche et al. [928] have described an automated apparatus for direct pSFC-TLC coupling. Compared to collecting the effluent from the SFC in decompression vessels, the direct deposition of the effluent on the TLC plate leads to significant losses of analytes. Multidimensional SFC has been reviewed [929]. [Pg.550]

The core - flood apparatus is illustrated in Figure 1. The system consists of two positive displacement pumps with their respective metering controls which are connected through 1/8 inch stainless steel tubing to a cross joint and subsequently to the inlet end of a coreholder 35 cm. long and 4 cm. in diameter. Online filters of 7 im size were used to filter the polymer and brine solutions. A bypass line was used to inject a slug of surfactant solution. Two Validyne pressure transducers with appropriate capacity diaphragms are connected to the system. One of these measured differential pressure between the two pressure taps located about one centimeter from either end of the coreholder, and the other recorded the total pressure drop across the core and was directly connected to the inlet line. A two - channel linear strip chart recorder provided a continuous trace of the pressures. An automatic fraction collector was used to collect the effluent fluids. [Pg.245]

This was significant in the preparation of l,2-dimethyl-3-hydroxy-4-pyridone, employed clinically as an iron chelating agent. The aminoreductone is obtained by reaction of methylamine with maltol. Traces of metal within the system readily form highly colored complexes with reactant or product and these are difficult to remove. With the CMR, the preparation was achieved in 65 % yield without the need for decolorizing charcoal and the product was crystallized by collecting the effluent in acetone (Scheme 2.10) [22]. [Pg.48]

Wastewater samples have usually been collected in precleaned amber glass containers. Both discrete and composite samples have been used for the analysis of effluents and influents of WWTPs. Unpreserved samples are normally stored at 4 °C for 48 h, or frozen [48]. Other authors add chemical agents such as methanol, sulfuric acid, or mercuric chloride to prevent bacterial activity during storage, and/or store the samples in supports used for extraction [26,35,57]. [Pg.19]

However, full structural analysis of a lipid will often necessitate further analysis of the collected column effluent for a single GLC peak. Infrared and NMR spectroscopy and mass spectrometry are all useful techniques which will give information for identification purposes, including the position and configuration of any double bonds. [Pg.438]

We have developed and tested a metabolism system and regimen which allows collection of data comparable to those from terrestrial animals. The key to our experiments is a metabolism chamber, described previously Cl3, 14) CFig. 1), which can be operated in either the static or flow-through mode. Briefly, individuals or groups of animals are held at constant temperature in the jacketed glass chamber (A), on a stainless steel screen (B), while pure water or test solution is passed over them (or held under static conditions). Solid wastes are separated in a jacketed container (C) held near 0°C to minimize microbial action, and the effluent containing dissolved metabolites is passed onto a column of nonionic macroreticular adsoprtion resin where organic solutes are adsorbed from solution (D). [Pg.221]

Distributions of water and reactants are of high interest for PEFCs as the membrane conductivity is strongly dependent on water content. The information of water distribution is instrumental for designing innovative water management schemes in a PEFC. A few authors have studied overall water balance by collection of the fuel cell effluent and condensation of the gas-phase water vapor. However, determination of the in situ distribution of water vapor is desirable at various locations within the anode and cathode gas channel flow paths. Mench et al. pioneered the use of a gas chromatograph for water distribution measurements. The technique can be used to directly map water distribution in the anode and cathode of an operating fuel cell with a time resolution of approximately 2 min and a spatial resolution limited only by the proximity of sample extraction ports located in gas channels. [Pg.509]


See other pages where Collection of effluents is mentioned: [Pg.49]    [Pg.49]    [Pg.287]    [Pg.22]    [Pg.181]    [Pg.23]    [Pg.23]    [Pg.412]    [Pg.141]    [Pg.49]    [Pg.49]    [Pg.287]    [Pg.22]    [Pg.181]    [Pg.23]    [Pg.23]    [Pg.412]    [Pg.141]    [Pg.58]    [Pg.427]    [Pg.2207]    [Pg.17]    [Pg.167]    [Pg.545]    [Pg.82]    [Pg.432]    [Pg.449]    [Pg.88]    [Pg.794]    [Pg.210]    [Pg.627]    [Pg.222]    [Pg.620]    [Pg.647]    [Pg.351]    [Pg.369]    [Pg.106]    [Pg.129]    [Pg.110]    [Pg.87]    [Pg.200]    [Pg.171]   
See also in sourсe #XX -- [ Pg.48 ]




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Effluent

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