Introduction to Modern Liquid Chromatography, Third Edition part 30 pot

... REVERSED-PHASE CHROMATOGRAPHY (NARP), 295 6.6 SPECIAL PROBLEMS, 297 6.6.1 Poor Retention of Very Polar Samples, 297 6.6.2 Peak Tailing, 298 Introduction to Modern Liquid Chromatography, Third Edition, by ... N Totally porous 5 30 2,500–3,000 Totally porous 5 50 4,500–5,000 Totally porous 5 100 8,000–10,000 Totally porous 5 150 12,000–15,000 Totally porous 5 250 20,000–25,000 To...

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... 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-Array Detectors, 165 4.4.4 ... REVERSED-PHASE, ION-PAIR, AND ION- EXCHANGE CHROMATOGRAPHY 303 7.1 Introduction, 304 7.2 Acid–Base Equilibria and Reversed-Phase Retention, 304 7.2.1 Choice of Buffers, 309 7.2.1.1...

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... follows: (150 × 4.6-mm, 5-μm particles) V s ≤ 80 μL; (100 × 4.6-mm, 3-μm particles) V s ≤ 50 μL; (30 × 4.6-mm, 3-μm particles) V s < 30 μL; (30 × 2.1-mm, 1.5-μm particles) V s < 4 μL. If ... 1 to 4, the peak begins to widen and then develops a flat top. For Equation (2.27) and the examples of Figure 2.22, we assume the delivery of an undistorted (i.e., cylindrical) sample plug t...

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... the total of the autosampler -to- column plus column -to- detector connections. Sometimes it is advantageous to use a short piece of 0.007-in i.d. tubing between the autosampler and column, so as to ... with pressures up to 6000 psi between the pump and detector, so the tubing must be able to withstand such pressures. Also tubing used to transport the sample from the autosampler to...

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... directed to a photodetector, where it is monitored and converted to an electronic signal for data processing. Because fluorescence is emitted in all directions, it is common to monitor the emitted ... carried out at detector startup identify many potential detector problems and can provide automatic wavelength calibration. The background, or baseline absorbance, of UV detectors can incre...

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... pack- ing particles. To prevent particle aggregation, the interaction of the particle with the slurry liquid should be stronger than interactions between particles. For example, C 8 -orC 18 -modified particles ... as illustrated by the cartoon of Figure 5.25a, the liquid may be acceptable. However, if the particles tend to aggregate as in Figure 5.25b, the liquid is likely a poor cho...

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... so that on average a change in %B by a factor of two (e.g., a change in mobile phase from 100% B to 50% B) will change values of k by a factor of 2 to 4. Similar plots of log k against log %B ... Indicated Wavelength (nm) 200 210 220 230 240 250 260 Acetonitrile a,b 0.52 3.1 0.03 0.02 0.00 0.00 0.00 0.00 0.00 Ethoxynonafluorobutane 0.01 h Presumed similar to ethyl ether Chloroform c 0.2...

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... runs, see [14]). It should be 10.1 INTRODUCTION 479 50°C 35% B 30 C 35% B 50°C 45% B 30 C 45% B (a) 50°C t G = 10 min 30 C t G = 10 min 30 C t G = 30 min 50°C t G = 30 min (b) pH−2.5 t G = 10 min pH−3.0 t G = ... min pH−3.0 t G = 10 min pH−3.5 t G = 10 min pH−2.5 t G = 30 min pH−3.0 t G = 30 min pH−3.5 t G = 30 min (d) ACN MeOH 1:1 THF 1:1 1:1 1:1:1 (f ) 30% ACN 15% ACN+ 20%...

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... hand. Second, the data system and associated software must be able to convert the HPLC Introduction to Modern Liquid Chromatography, Third Edition, by Lloyd R. Snyder, Joseph J. Kirkland, and John W. ... quantification. One way to minimize this problem is to stop integration when the peak is sure to have left the detector. This can be accomplished by visually determining w...

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... 513 E 2 the error due to the autosampler, or E 3 the error due to signal -to- noise (Eq. 11.1). As a rule, if the RSD of an error source is less than half the total RSD, its contribution to total RSD will ... automatically assign it to the forced time point for all chromatograms. It is a good practice to visually examine every chromatogram to confirm that the integration is correct...

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