Research Synopsis

Research in our lab concerns harnessing the power of techniques such as capillary electrophoresis (CE), capillary liquid chromatography (LC), and mass spectroscopy (MS), to solve problems in complex mixture analysis. Samples of biological and environmental origin are usually complex in character, containing many hundreds to thousands of detectable compounds. Mixtures of such great complexity are a challenge to the resolving power of existing analytical methods. For an analytical technique to successfully handle such samples, the technique must have either extreme selectivity for a particular compound of interest, or the technique must provide a great excess of resolution space (peak capacity) for the compounds to be resolved into.

We are currently pursuing techniques of great peak capacity, such as combined liquid chromatography-capillary electrophoresis (LC-CE), as well as techniques with extreme resolving power, such as ultra high pressure LC and ultra high voltage CE. Combinations of chromatography with mass spectrometry have long been recognized as having the requisite selectivity to permit effective complex mixture analysis. We are exploring the possibilities of combining two separation columns to provide much greater peak capacity. Combinations such as LC-CE and LC-LC are being developed for this purpose. These combinations of two separation techniques are done in what we refer to as a "comprehensive" manner; all components of the sample are subjected to full two-dimensional analysis. Comprehensive LC-CE has generated peak capacities in excess of 20,000 peaks. Such systems permit effective analysis of mixtures containing thousands of detectable compounds. We are also initiating work on LC-LC-MS and LC-CE-MS as systems of extraordinary power for analysis of complex mixtures. The combination of these two-dimensional separation systems with mass spectrometry should permit the further resolution of compounds, and aid greatly in the identification of compounds.