An overview of the importance and utility of multi-dimensional separation methods.

Multidimensional Liquid Chromatography:  a growing addition to separation science technology.

By Christina Jayne Vanhinsbergh, PhD researcher in 2D-LC, University of Sheffield.

Many industries rely heavily on liquid chromatographic separations for the analysis of molecular products, active pharmaceutical ingredients, reaction components and toxic substances.  Improvements in stationary phase chemistry, along with reduction in particle size has helped to increase selectivity and peak capacity dramatically over the past decade.

A drawback for many separations, however, is that molecular species analysed today are structurally and physiochemically closely related.  This, along with biased separation mechanisms, can lead to co-elution or reduced resolution of analytes.

Multidimensional chromatography couples orthogonal modes of separations to overcome challenging analyses.  Orthogonal separations can pre-treat samples, simplify complex chromatography, as well as resolve co-eluting species.  The technique is developing into both comprehensive and selective approaches, suited to the analytical drivers of separation.

Multidimensional liquid chromatography also has the potential for reducing reliance on technologies requiring highly skilled analysts, such as mass spectrometry – as separation of critical species reduces the requirement for targeted mass detection over a peak.  In workflows where mass spectrometry is utilised, increases in peak capacity and resolution can improve quantitative analysis.