Introduction to Modern Liquid Chromatography, Third Edition part 7 pptx

... 74 2 .7. 2 Gradient Elution, 75 2 .7. 3 Peak Capacity and Two-dimensional Separation, 76 2 .7. 4 Peak Tracking, 77 2 .7. 5 Secondary Equilibria, 78 2 .7. 6 Column Switching, 79 2 .7. 7 Retention Predictions ... Separation, 70 2.6.2 Mass Overload: Effect of Sample Weight on Separation, 71 2.6.3 Avoiding Problems due to Too Large a Sample, 73 2 .7 RELATED TOPICS, 74 2 .7....

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... 3 4 5 6 7 8 9 10 11 12 13 14 15 (a) (b) 3 4 5 6 7 13 12 10 9 14 16 15 17 19 20 21 27 29 28 24 23 30 34 32 31 33 35 36 39 41 46 42 43 47 48 51 50 49 44 45 52 53 54 56 55 57 63 67 71 72 73 74 77 76 73 70 69 68 82 81 78 75 85 83 87 89 88 86 89 90 ... most laboratories that deal with a need for analyzing chemical mixtures are equipped for HPLC; it is often the first choi...

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... General UV-Detector Characteristics, 166 4.5 FLUORESCENCE DETECTORS, 1 67 4.6 ELECTROCHEMICAL (AMPEROMETRIC) DETECTORS, 170 4 .7 RADIOACTIVITY DETECTORS, 172 4.8 CONDUCTIVITY DETECTORS, 174 4.9 CHEMILUMINESCENT ... 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...

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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 ... preparing totally porous silica particles is to aggre- gate or assemble microparticles, as illustrated in Figure 5.10. One such procedure is to disperse a silica sol of define...

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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; ... 6.4.1.4). 6.3 SELECTIVITY 2 67 (d) 1 1.5 2.0 2.5 3.0 4.0 3.5 3.0 2.5 2.0 S log k w “irregular” r 2 = 0. 87 (c) %B (100f) 0 10203040506 070 2.0 1.5 1.0 0.5 0.0 1 2 3 4...

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... 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 that an ... peak is seen in Figure 7. 5 for a mobile-phase pH = 3.0. As the pH increases to 3.5 (Fig. 7. 5b) and 4.0 (Fig. 7. 5c), the peak progressively broadens and becomes more distorted (peak f...

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... (min) Time ( min ) Time ( min ) 02468 Time (min) 02468 4 5 7 6 4 5 6 7 1 2 3 4 5 6 7 4 5 7 6 0 2 4 6 8 0 2 4 6 8 10 12 4 + 5 7 6 4 + 5 7 6 (a) (b) (c) (d) (e) (f ) Figure 7. 15 IPC separation of a sample of water-soluble ... From these initial experiments (Fig. 7. 15a–c), it appears that a hexane sulfonate concen- tration of 6 to 7 mM would provide maximum resolution of peak...

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... × 4.0-mm silica column (5-μm particles); 1.5% methanol-methylene chloride; 25 ◦ C; 1mL/min.(a) Fresh sample; (b) degraded sample of polymer (stored at pH -7. 4 and 37 ◦ C for 60 days); (c) degraded ... 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...

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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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... need to be applied to this value before the final sample concentration is reported. 11.4 QUANTITATIVE ANALYSIS 521 it in water or buffer to make a primary stock. This stock then is added to the ... 11.8 to 11.10 for Same Analyte and Separation Conditions Response Concentration (ng/mL) External Standard a Internal Standard b Standard Addition c 0 4 87 1 215 0.0408 72 9 2 416 0. 078...

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