Introduction to Modern Liquid Chromatography, Third Edition part 18 ppt

... a graphical chromatogram for a visual inspection of the quality of the data. As laboratories move to paperless records, the chromatogram may be viewed only on a computer monitor. For qualitative ... result, when a regulatory auditor reviews the data. It is expected that as additional regulatory requirements are placed on the HPLC laboratory, software manufacturers will continue to provide...

Ngày tải lên: 04/07/2014, 01:20

... 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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... surrounds each particle as (a) (b) (c) Column, showing mobile-phase flow inlet outlet mobile phase pore Particle and surrounding mobile phase stationary phase C 18 C 18 C 18 C 18 C 18 C 18 mobile ... Switching, 79 2.7.7 Retention Predictions Based on Solute Structure, 80 Introduction to Modern Liquid Chromatography, Third Edition, by Lloyd R. Snyder, Joseph J. Kirklan...

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... Equations (2 .18) and (2.18a). The total porosity of the column (as a fraction of the column volume) is defined as ε T , and is composed of the intra-particle porosity ε i , plus the inter-particle ... increase in proportion to retention time. A continual increase in peak width from the beginning to the end of the chromatogram is therefore observed; for example, see the chromatogram of Fig...

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... R s ≥ 2), normally corresponding to a one -third safety factor (vs. baseline separation with R s ≈ 1.5, for peaks of comparable size). The goal of R s ≥ 2 takes into account minor peak tailing, ... choice of column length, particle size, and flow rate will always correspond to a minimum value of h ≈ 2(orν ≈ 3). Because commercial columns are limited to certain lengths and particle sizes...

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... laboratories have preferred columns packed with -5μm particles. Such columns are less demanding in terms of equipment (Section 3.9), and are less likely to be plugged by particulates. Today, ... by conventional HPLC systems (with maximums of 6000 psi or 400 bar) is referred to as ultra–high-pressure liquid chromatography, or U-HPLC. U-HPLC, with pressures > 6000 psi can be used for...

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... 186 4.14.2 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 ... Light-Scattering Detector (CNLSD), 182 4.12.3 Laser Light-Scattering Detectors (LLSD), 183 4.13 CORONA-DISCHARGE DETECTOR (CAD), 184 4.14 MASS SPECTRAL DETECTORS (MS), 1...

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... cell dual photodiode detector output (a) photodiode arra y (b) Figure 4.22 Schematic of a deflection refractive index (RI) detector. (a) Dual-photodiode detector; (b) photodiode array detector (lamp and flow ... heat-exchanger required Sensitive to temperature changes Reliable, fairly easy to operate Nondestructive of photodiode-array technology to the RI detector allows multiple photodio...

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... detector response to reagents to reduce extra-column peak broadening during reaction is to use a knitted reactor, where narrow-bore flexible tubing is knitted into a series of tight radius bends to create ... fast reaction is desired to minimize the reactor volume requirements. Also reactions that go to completion tend to be more reproducible than those that only go partially to...

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... J. N. Seiber, Anal. Chem., 49 (1977) 326. 11. L. R. Snyder and J. J. Kirkland, Introduction to Modern Liquid Chromatography,1 st ed., Wiley, New York, 1979, p. 136. 12. J. W. Dolan, LCGC, 14 (1996) ... Pressure Ruggedness Operator Column Type Speed Convenience Stability a 5-μm totally porous 1 4 4 4 4 3.5 totally porous 2 3 4 4 4 2- to 3-μm totally porous 3 2 2 3 3 <2-μm totally...

Ngày tải lên: 04/07/2014, 01:20