What I Learned about Separations While on my Tasmanian Sabbatical

with Joe Foley
Thursday, February 23, 2017
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About This Meeting

Abstract:  

This talk will summarize three of many research topics explored during my 2015-2016 sabbatical at ACROSS in Hobart, in addition to telling you a few things you may not know about Tasmania.

1.  Size exclusion chromatography (SEC) using reversed-phase (RP) and HILIC columns.  Some minor disadvantages notwithstanding, the performance of RP and HILIC columns for the separation and molar mass distribution measurement of synthetic (and potentially bio-) polymers is often better than for commercial SEC columns for reasons to be explained.  Although there are many considerations, the most important is the use of a mobile phase that both (i) solvates the polymers of interest and (ii) is sufficiently ‘strong’ to preclude interactions with (but not pore penetration into) the porous stationary phase.

2.  Peak capacity in capillary/microchip electrophoresis and the probability of success.  Largely because of the increased popularity in two-dimensional separations, peak capacity is now one of the most popular chromatographic figures of merit. Although its importance in capillary and microchip electrophoresis is also recognized, even a moderately rigorous analysis has yet to be reported, in contrast to the well-developed theories for one- and two-dimensional chromatography.  We report our findings to date, including the tradeoff between peak capacity and analysis time for co- and counter-electroosmotic ions.

3.  A novel type of sample modulation in comprehensive two-dimensional liquid chromatography (LC x LC).  We report here the first successful (to our knowledge) on-line technique for achieving thermal modulation in LC x LC.  Whereas thermal modulation has been employed in GC x GC for nearly two decades using a variety of approaches, the much more unfavorable physicochemical properties of liquids compared to gases with respect to heat capacity, heat transfer, etc. have made thermal modulation in LC x LC quite challenging.  The design and results of a prototype thermal modulator are described.  

Speakers
Joe Foley
Drexel University