Page 12 - Multidimensional Chromatography

PREFACE

Separation Science is a mature and unified subject in which now conventional chro-
matographic and electrically driven processes are applied in the analysis of mixtures
of compounds ranging from permanent gases to proteins. The boundaries between
previously distinct techniques are increasingly blurred and it is becoming very evi-
dent that is a single theory may be applicable to chromatography whatever the physi-
cal state of the mobile phase. Gas, liquid and supercritical fluid chromatography can
be regarded as special cases of the same procedure, while capillary electrochro-
matography combines liquid chromatography with electrophoresis.
Separation science is now very focused on reducing not only timescales for ana-
lyzis, but also the size and physical nature of the analytical device, Miniaturisation
of entire analytical procedures provides a strong driving force for these trends in
unifying theory and practice, and is a process likely to continue, as separations using
microfluidic devices are developed. In spite of these many advances however,
the complexity of many naturally occurring mixtures exceeds the capacity of any
single method, even when optimized to resolve them. For many years therefore,
intense effort has been concentrated on coupling separations methods together to
increase resolution, and these have proceeded parallel with advances in coupling
separation methods with spectroscopy. As our ability to isolate components in mix-
tures has increased, so has our appreciation for the shear complexity of compounds
found in nature, Even separation systems with the capacity to isolate many thou-
sands of species, are found to be inadequate when applied to commonplace mixtures
such as diesel fuel. We clearly have some way to go in realising separation systems
that can provide truly universal and complete separations.
Recent advances in multidimensional separation methods have been rapid and we
considered that the time was appropriate to bring together accounts by leading
researchers who are developing and applying multidimensional techniques. These
authors have emphasized underlying theory along with instrumentation and practi-
calities, and have illustrated techniques with real-world examples. We hope that the
eader will be as excited as we are by this combined account of progress. We thank all
our contributors for their significant efforts in producing chapters of high scientific
quality. We are especially indebted to Katya Vines of John Wiley who guided the
project through its early stages and more recently to Emma Dowdle who brought it
to completion.
KEITH BARTLE, Leeds
ALLY LEWIS, Leeds
LUIGI MONDELLO, Messina