... through detector +
connecting tubing
(extra-column peak broadenin
g
)
(e)(f )
1
2
3
4
5
6
7
9
8
2
3
1
2
3
4
5
6
8
7
9
Detector
particle
pore
Figure 2.12 Illustration of various contributions to band ... 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 chromatogr...
... Anal. Chem., 39 ( 196 7) 698 , 705.
24. R. P. W. Scott, W. J. Blackburn, and T. J. Wilkens, J. Gas Chrommatogr., 5 ( 196 7) 183.
25. J. J. Kirkland, ed., Modern Practice of Liquid Chromatography, Wiley-Interscience, ... Equilibria, 78
2.7.6 Column Switching, 79
2.7.7 Retention Predictions Based on Solute Structure, 80
Introduction to Modern Liquid Chromatography, Third Ed...
... ≈1-μm particles will be
required. In the second case (N = 300,000), 9 μm particles are recommended. That
is, fast separations require smaller particles, while large N separations require larger
particles ... 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 pe...
... 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 f...
... a total of three paragraphs were devoted to
chromatographic data systems. Perhaps no other factor in HPLC practice has been
impacted more in the interceding years than data handling. In 197 9, ... 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...
... 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, ... Infrared (FTIR), 191
4.15.2 Nuclear Magnetic Resonance (NMR), 192
4.16 SAMPLE DERIVATIZATION AND REACTION DETECTORS, 194
4.1 INTRODUCTION
The detector for the first liquid...
... 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...
... 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...
... Anal. Chem., 49 ( 197 7) 326.
11. L. R. Snyder and J. J. Kirkland, Introduction to Modern Liquid Chromatography,1 st
ed., Wiley, New York, 197 9, p. 136.
12. J. W. Dolan, LCGC, 14 ( 199 6) 378.
13. ... ( 199 3) 288.
21. A. G. Frenich, J. R. Torres-Laasio, K. De Braekeleer, D. L. Massart, J. L. Martinez-Vidal,
and M. M. Galera, J. Chromatogr. A, 855 ( 199 9) 487.
22. Waters 99 6 Pho...