Chromatography schematic

Figure 4.2—Stationary phases in ion chromatography. Schematic of a polystyrene sphere used as a cation exchanger. The polystyrene matrix is transformed into a resin that can exchange cations (e.g. DOWEX 4) or into an anion exchange resin (e.g. DOWEX - MSA-l, or Permutite" if R = CH,).

In gas chromatography (schematic in Figure 5.14), the solid phase is usually silica coated with an involatile silicone polymer. Columns may be 10-100 m in length, so separation is usually excellent. Materials are eluted in approximate order of their boiling points (so this only works if they are reasonably volatile and do not decompose readily on heating). Detection of material being eluted relies on a thermal conductivity detector or flame ionization detector. The thermal conductivity detector depends on the fact that the conductivity of gas plus eluent is different from that of gas... 

Alternatively, gas chromatography may be used Fig. XVII-5 shows a schematic readout of the thermal conductivity detector, the areas under the peaks giving the amount adsorbed or desorbed. 

Schematics showing the basis of separation in (a) adsorption chromatography, (b) partition chromatography, (c) ion-exchange chromatography, (d) size-exciusion chromatography, and (e) eiectrophoresis. For the separations in (a), (b), and (d) the soiute represented by the soiid circie ( ) is the more strongiy retained.

In gas chromatography (GC) the sample, which may be a gas or liquid, is injected into a stream of an inert gaseous mobile phase (often called the carrier gas). The sample is carried through a packed or capillary column where the sample s components separate based on their ability to distribute themselves between the mobile and stationary phases. A schematic diagram of a typical gas chromatograph is shown in Figure 12.16. 

Schematic diagram of an injector for packed coiumn gas chromatography.

Schematic diagram of a thermai conductivity detector for gas chromatography.

Schematic diagram of an orthogonal Q/TOF instrument. In this example, an ion beam is produced by electrospray ionization. The solution can be an effluent from a liquid chromatography column or simply a solution of an analyte. The sampling cone and the skimmer help to separate analyte ions from solvent, The RF hexapoles cannot separate ions according to m/z values and are instead used to help confine the ions into a narrow beam. The quadrupole can be made to operate in two modes. In one (wide band-pass mode), all of the ion beam passes through. In the other (narrow band-pass mode), only ions selected according to m/z value are allowed through. In narrow band-pass mode, the gas pressure in the middle hexapole is increased so that ions selected in the quadrupole are caused to fragment following collisions with gas molecules. In both modes, the TOF analyzer is used to produce the final mass spectrum.

FIG. 16"37 Schematic showing the intersection of the operating line with the pure-component isotherms in displacement chromatography. Conditions are the same as in Fig. 16-36. 

Fig. 14-5. Schematic diagram of hydrocarbon detection by gas chromatography. NMVOC, nonmethane volatile organic carbon.

Fig. 17. A schematic of the alkane line obtained by inverse gas chromatography (IGC) measurements. The relative retention volume of carrier gas required to elute a series of alkane probe gases is plotted against the molar area of the probe times the. square root of its surface tension. The slope of the plot is yielding the dispersion component of the surface energy of...

FIGURE 23.1 Schematic of a high osmotic pressure chromatography system. 

Figure 2.12 Schematic representation of an on-line SPE-GC system consisting of three switching valves (VI-V3), two pumps (a solvent-delivery unit (SDU) pump and a syringe pump) and a GC system equipped with a solvent-vapour exit (SVE), an MS instrument detector, a retention gap, a retaining precolumn and an analytical column. Reprinted from Journal of Chromatography, AIIS, A. J. H. Eouter et al, Analysis of microcontaminants in aqueous samples hy fully automated on-line solid-phase extraction-gas chromatography-mass selective detection , pp. 67-83, copyright 1996, with permission from Elsevier Science.

Figure 2.17 Schematic representation of the set-up used for on-line liquid-liquid exti action coupled with capillary GC when using a membrane phase separator. Reprinted from Journal of High Resdution Chromatography, 13, E. C. Goosens et al., Determination of hexachloro-cyclohexanes in gi ound water by coupled liquid-liquid extraction and capillaiy gas cliro-matography , pp. 438-441, 1990, with permission from Wiley-VCH.

Figure 2.20 Schematic representation of the set-up used for on-line exti action-GC VI and V2, valves PI and P2, syringe pumps L, sample loop CC flow, countercunent flow CT, cold ti ap. Reprinted from Journal of High Resolution Chromatography, 16, H. G. J. Mol et ai, Use of open-tubular tapping columns for on-line exti action-capillary gas cluomatography of aqueous samples , pp. 413-418, 1993, with permission from Wiley-VCH.

Figure 5.2 Schematic representation of the final column-switching system (a) foi ward-flush position (b) back-flush position (further details are given in the text). Reprinted from Journal of Chromatography, A 828, A. K. Sakhi et al. Quantitative determination of endogenous retinoids in mouse embiyos by high-performance liquid cliromatography with on-line solid-phase exti action, column switcliing and electi ochemical detection , pp. 451 -460, copyright 1998, with permission from Elsevier Science.

Figure 5.4 Schematic diagrams of a heait-cut valve configuration system. Reprinted from Journal of Chromatography, 602, S. R. Villasenor, Matrix elimination in ion cliromatography by heart-cut column switching techniques , pp. 155-161, copyright 1992, with permission from Elsevier Science.

The basic instrument required for packed-column unified chromatography is shown schematically in Figure 7.9. This is essentially a two-pump HPLC instrument utilizing high-pressure mixing with just a few new components. At least one pump must... 

Figure 7.9 Schematic diagram of the basic instmmentation used for Unified Chromatography.

Figure 9.3 Schematic illustration of the electrophoretic transfer of proteins in the chromatophoresis process. After being eluted from the HPLC column, the proteins were reduced with /3-mercaptoethanol in the protein reaction system (PRS), and then deposited onto the polyacrylamide gradient gel. (PRC, protein reaction cocktail). Reprinted from Journal of Chromatography, 443, W. G. Button et al., Separation of proteins by reversed-phase Mgh-performance liquid cliromatography , pp 363-379, copyright 1988, with permission from Elsevier Science.

Figure 10.4 Schematic representation of the multidimensional GC-IRMS system developed by Nitz et al. (27) PRl and PR2, pressure regulators SV1-SV4, solenoid valves NV— and NV-I-, needle valves FID1-FID3, flame-ionization detectors. Reprinted from Journal of High Resolution Chromatography, 15, S. Nitz et al, Multidimensional gas cliro-matography-isotope ratio mass specti ometiy, (MDGC-IRMS). Pait A system description and teclinical requirements , pp. 387-391, 1992, with permission from Wiley-VCFI.

A method which uses supercritical fluid/solid phase extraction/supercritical fluid chromatography (SE/SPE/SEC) has been developed for the analysis of trace constituents in complex matrices (67). By using this technique, extraction and clean-up are accomplished in one step using unmodified SC CO2. This step is monitored by a photodiode-array detector which allows fractionation. Eigure 10.14 shows a schematic representation of the SE/SPE/SEC set-up. This system allowed selective retention of the sample matrices while eluting and depositing the analytes of interest in the cryogenic trap. Application to the analysis of pesticides from lipid sample matrices have been reported. In this case, the lipids were completely separated from the pesticides. 

Figure 10.14 Schematic representation of the SFSPE/SFC set-up developed by Murugaverl and Vooi hees (67). Reprinted from Journal of Microcolumn Separation, 3, B. Mumgaverl and K. J. Vooi hees, On-line supercritical fluid exti aaion/chromatography system for ti ace analysis of pesticides in soybean oil and rendered fats , pp. 11-16, 1991, with permission from John Wiley and Sons, Inc.

Figure 12.19 Schematic diagram of the interface system used for supercritical fluid cliromatography-gas chromatography. Reprinted from Journal of High Resolution Chromatography, 10, J. M. Levy et al., On-line multidimensional supercritical fluid clrromatogi a-phy/capillary gas chromatography , pp. 337-341, 1987, with permission from Wiley-VCH.

Figure 12.24 Schematic diagram of the multidimensional packed capillary to open tubular column SFC-SFC system. Reprinted from Analytical Chemistry, 62, Z. Juvancz et al., Multidimensional packed capillary coupled to open tubular column supercritical fluid chromatography using a valve-switching interface , pp. 1384-1388, copyright 1990, with permission from the American Chemical Society.

Figure 13.5 Schematic presentation of the procedure involved in coupled-column RPLC AS, autosampler C-1 and C-2, first and second separation columns, respectively M-1 and M-2, mobile phases S-1 and S2, interferences A, target analytes HV, high-pressure valve D, detector. Reprinted from Journal of Chromatography, A 703, E. A. Hogendoom and R van Zoonen, Coupled-column reversed-phase liquid cliromatography in environmental analysis , pp. 149-166, copyright 1995, with permission from Elsevier Science.

Fig. 20 Schematic representation of an eiectric spark discharge chamber for the activation of gases at normal atmospheric pressure for the production of fluorescence in substances separated by thin-layer chromatography [2],...

The recycle reactor is shown schematically in Figure 1. It consists of a catalytic or electrocatalytic reactor unit with a bypass loop, a recycle pump and a molecular sieve trap unit. The latter comprises one or two packed bed columns in parallel each containing 2-10 g of Linde 5A molecular sieve pellets. On line gas chromatography (Shimadzu 14A) was used for the analysis of CH4, O2, CO, CO2, C2H4 and C2H6 in the reactants and products. 

The use of column chromatography for fractionating polymer latex suspensions has been growing rapidly. Fig ire 1 shows a schematic breaikdown of the severeil methods. 

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