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J. Kuligowski, G. Quintas, M. de la Guarida, B. Lendl:
"Analytical potential of mid-infrared detection in capillary electrophoresis and liquid chromatography: A review";
Analytica Chimica Acta (eingeladen), 679 (2010), S. 31 - 42.

Literature published in the last decade concerning the use of mid-infrared spectrometry as a detection
system in separation techniques employing a liquid mobile phase is reviewed. In addition to the continued
use of isocratic liquid chromatographic (LC) techniques, advances in chemometric data evaluation
techniques now allow the use of gradient techniques on a routine basis, thus significantly broadening
the range of possible applications of LC-IR. The general trend towards miniaturized separation systems
was also followed for mid-IR detection where two key developments are of special importance. Firstly,
concerning on-line detection the advent of micro-fabricated flow-cells with inner volumes of only a few
nL for transmission as well as attenuated total reflection measurements enabled on-line mid-IR detection
in capillary LC and opened the path for the first successful realization of on-line mid-IR detection in
capillary zone electrophoresis as well as micellar electrokinetic chromatography. Secondly, concerning
off-line detection the use of micro-flow through dispensers now enables to concentrate eluting analytes
on dried spots sized a few tens of micrometers, thus matching the dimensions for sensitive detection by
mid-IR microscopy. Finally in an attempt to increase detection sensitivity of on-line mid-IR detection,
mid-IR quantum cascade lasers have been used. Applications cover the field of food analysis, environmental
analysis and the characterization of explosives among others. Best detection sensitivities for on-line
and off-line detection have been achieved in miniaturized systems and are in the order of 50 ng and 2 ng
on column, respectively.
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