Text Box: HIGH-EFFICIENCY LIQUID CHROMATOGRAPHY SEPARATIONS
ACHIEVED BY MONOLITHIC SILICA COLUMNS

KOSUKE MIYAMOTO1, TOHRU IKEGAMI1, TAKESHI HARA2, YASUSHI ISHIHAMA3,
AND NOBUO TANAKA1, 4
1KYOTO INSTITUTE OF TECHNOLOGY, DEPARTMENT OF BIOMOLECULAR ENGINEERING, MATSUGASAKI,
SAKYO-KU, KYOTO 606-8585, JAPAN; 2PHYSICAL CHEMISTRY INSTITUTE, JUSTUS LIEBIG UNIVERSITY
GIESSEN, 58 HEINRICH BUFF RING, D-35392 GIESSEN, GERMANY; 3KYOTO UNIVERSITY, GRADUATE
SCHOOL OF PHARMACEUTICAL SCIENCES, YOSHIDA, SAKYO-KU, KYOTO 606-8501, JAPAN; AND
4GL SCIENCES, 237-2 SAYAMAGAHARA, IRUMA 358-0032, JAPAN

Introduction

	Ultrahigh column efficiency has been the focus of many chromatographers
studying theories, columns, packing materials, or the separation of complex
mixtures. Increasing the plate number (N) of a separation medium is the
simplest way to increase separation capability, as resolution of two adjacent
peaks (Rs) is proportional to √N. Such motivation could also be a driving force
for a new technique and the advances of separation science. The possibility of
generating a large number (e. g., 100,0001,000,000) of theoretical plates has
been studied since the beginning of high-performance liquid chromatography
(HPLC), especially in liquid chromatography (LC) using particle-packed
columns, where it is hard to achieve because of the relatively slow molecular
diffusion of a solute in liquid phase. Guiochon recently discussed in detail the
limit in performance of LC (Guiochon, 2006). Here we briefly review some
studies that explore extremely high column efficiency. We also discuss possibilities
of practical uses of monolithic silica columns capable of generating
100,0001,000,000 theoretical plates.
	In LC, the efficiency (N, number of theoretical plates, equation 1) of a
column (length L), is related to the plate height (H, equation 2), the particle
size (dp) of packing materials, and the variance (σ2) of a Gaussian-shaped solute
band acquired by the solute during its migration through a column. A reduced
plate height (h) measures about 2 in a conventional system, which comprises
pressure-driven operation of a packed column at optimum linear velocity. N
can be calculated from a retention time of a solute (tR) and the base peak width
(tW=4σ, σ is a standard deviation) for a symmetrical peak.

This was a sample page from the book to give you an idea of what is discussed.

To learn more about HPLC on Monolithic Silica Columns, Buy the Book!

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Prof. Dr. Nobuo Tanaka et al.

 

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