Introduction to Modern Liquid Chromatography, Third Edition part 78 pptx

... be given to the tubing from the detector outlet, since small-i.d. tubing combined with higher flow rates can lead to a higher back-pressure and damage to the detector flow cell. It may be necessary to ... of the tee to the fraction collector. Care should be taken in balancing the flow rates to ensure that the detector output is synchronized with the peaks entering the fraction collec...

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... most laboratories that deal with a need for analyzing chemical mixtures are equipped for HPLC; it is often the first choice of technique Introduction to Modern Liquid Chromatography, Third Edition, ... Do?, 4 1.2 A SHORT HISTORY OF HPLC, 6 1.3 SOME ALTERNATIVES TO HPLC, 8 1.3.1 Gas Chromatography (GC), 8 1.3.2 Thin-Layer Chromatography (TLC), 9 1.3.3 Supercritical Fluid Chromato...

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... 77 2.7.5 Secondary Equilibria, 78 2.7.6 Column Switching, 79 2.7.7 Retention Predictions Based on Solute Structure, 80 Introduction to Modern Liquid Chromatography, Third Edition, by Lloyd R. Snyder, Joseph ... Thin-layer Chromatography, Wiley-Interscience, New York, 1 978, pp. 5–8. 18. J. C. Moore, J. Polymer Sci. Part A, 2 (1964) 835. 19. L. S. Ettre and A. Zlatkis, eds.,...

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... Quadrupoles and Ion Traps, 188 4.14.3 Other MS Detectors, 190 4.15 OTHER HYPHENATED DETECTORS, 191 Introduction to Modern Liquid Chromatography, Third Edition, by Lloyd R. Snyder, Joseph J. Kirkland, ... 158 4.3 INTRODUCTION TO INDIVIDUAL DETECTORS, 160 4.4 UV-VISIBLE DETECTORS, 160 4.4.1 Fixed-Wavelength Detectors, 163 4.4.2 Variable-Wavelength Detectors, 164 4.4.3 Diode-Arr...

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... heating, microparticles of silica spherical composit e Figure 5.10 Aggregation of microparticles to form totally porous particles. 212 THE COLUMN and the particles are strengthened by sintering. Small particles ... sol particles. Small, silica-sol particles are used to prepare particles with smaller pores; larger pores are formed from larger silica sol-particles. This aggregation method c...

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... 5,5-diphenylhydantoin; 3, acetophenone; 4, benzonitrile; 5, 5-phenylpentanol; 6,anisole;7, toluene; 8, cis-chalcone; 9, ethylbenzene; 10, trans-chalcone. Conditions: 150 × 4.6-mm (5-μm) columns; 45% acetonitrile-water; ... 5, 3,4-dichloroaniline; 6, 2-nitrotoluene; 7, 3-nitrotoluene; 8, toluene; 9,3-nitro-o-xylene; 10, 4-nitro-m-xylene. Conditions: 250 × 4.6-mm (5-μm) C 8 column; acetonitrile...

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... to ±1.5 unit for higher concentrations of the buffer). The buffer capacity of the mobile phase is proportional to buffer concentra- tion, which typically falls within a range of 5 to 25 mM. To ... reader may wish to skip this digression, proceed to Section 7.2.1.2, andreturntothepresent section as needed. We can define the ‘‘effective buffer capacity’’ of the mobile phase to mean...

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... sulfonate concen- tration of 6 to 7 mM would provide maximum resolution of peaks 4 to 7 (placing peak 5 midway between peaks 4 and 6, but without moving peak 7 too close to peak 6). Figure 7.15d–f ... C 8 column (3-μmparti- cles); 15% methanol- buffer (pH-3.2); 35 ◦ C; 2.0 mL/min. Chromatograms recreated from data in [48]. 338 IONIC SAMPLES: REVERSED-PHASE, ION-PAIR, AND ION-EXCHANGE CH...

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... required to achieve the desired retention range of 1 ≤ k ≤ 10, as well as to take advantage of solvent-strength selectivity. At the conclusion of exploratory TLC studies with silica plates, we need to ... often tolerate lower values of N (Section 15.4.1.1). 8.6 HYDROPHILIC INTERACTION CHROMATOGRAPHY (HILIC) Hydrophilic interaction chromatography (HILIC) can be regarded as normal-phase c...

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... behavior can make it extremely difficult to obtain reproducible isocratic separations of macromolecules in different laboratories, or even within the same laboratory. Furthermore the isocratic separation ... separations by RPC (with fixed run times, for automated analysis) are only practical by means of gradient elution and are commonly used to assay combinatorial libraries [3], as well as...

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