|Abstract Title:||Designing High Resolution Separations for Enhanced Characterisation of Petrochemical Samples|
|Presenter Name:||Prof Philip Marriott|
Abstract Information :
The analysis of petrochemicals has invariably employed leading-edge separation technologies and advanced solutions for detailed chemical analysis, whether it be multidimensional process analysers, supercritical fluid separations, or high-resolution capillary GC‒MS. In a crude oil sample, nature contrives to present the most difficult separation task for the analyst; in down-stream products, the legacy of the initial sample’s complexity may still remain. This is fertile ground for development of innovative and powerful separation solutions; this challenge exercises the best capabilities of the analyst.
We have contributed a number of new approaches to overall sample ‘global profiling’, with strategies to provide a best-case separation goal. These are based on well-established multidimensional gas chromatography (MDGC), and newer comprehensive two-dimensional GC (GC×GC) methods. We are interested in pushing these techniques to the limit of separation power by integrating additional dimensions of separations. We use multiple sampling strategies incorporating microfluidic switching, from a 1D column to a 2D column, with cryogenic zone compression and fast modulation to provide high efficiency for target sample analysis. This was demonstrated for oxygenated component identification in thermally stressed algae-derived jet fuel. 1D GC-MS was unable to identify these components. A similar approach was used for high sulfur oil shale samples. This design describes comprehensive MDGC incorporating multiple repeat injections with a shifted sampling strategy, to cover the whole sample. A further advanced mode using more than 2 columns that we call hybrid GC×GC-MDGC, functions as an on-line matrix clean-up method, or allows unique profiling of target chemical classes in ways never before possible. The role of these tools for discovery and improved characterisation will be described.