• Palestrante: Prof. Philip Marriot (Monash University – Australia);
  • 10 de dezembro de 2018 às 16h;
  • Sala: L774

 

Abstract:

Petrochemical analysis continues to be a major interest area for improvements in separation techniques due to the sheer complexity of the sample. 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; but we still cannot separate all components of interest. 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 even further dimensions of separations. [1] We use various multiple sampling strategies incorporating a Deans switch, 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 recently demonstrated for oxygenated component identification in thermally stressed algae-derived jet fuel. [2] [3] 1D GC-MS was unable to identify these components. A similar approach was used for high sulfur oil shale samples. [4]

A further advanced mode 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. [5]

Since GC is as much about separation as identification (best identification normally starts with best separation), we are interested in applying MDGC with both MS and NMR (off-line) and FTIR analysis, so that ultra-high chemical separation supported by characterisation tools of MS, NMR and FTIR [6] can provide added structural molecular assignment. Unfortunately NMR and classical light-pipe FTIR suffer from poor sensitivity, but we optimise injected sample quantity, and the number of repeat injections to advance our work. [7]

Literature

[1]. S.-T. Chin, P,J. Marriott. Multidimensional gas chromatography beyond simple volatiles separation. Chemical Communications, 50 (2014) 8819-8833

[2]. B. Mitrevski, R. Webster, P. Rawson, D. Evans, H.-K. Choi, P.J. Marriott. Multidimensional gas chromatography of oxidative degradation products in algal-derived fuel oil samples using narrow heartcuts and rapid cycle times

Journal of Chromatography A; 1224 (2012) 89-96.

[3] R. L. Webster, D. J. Evans, P, J. Marriott. Detailed chemical analysis by using multidimensional gas chromatography – mass spectrometry, and bulk properties of low temperature oxidized jet fuels. Energy & Fuels. 29 (2015) 2059-2066

[4]. M. W. Amer, B. Mitrevski, W.R. Jackson, A.L. Chaffee, P.J. Marriott. Multidimensional and comprehensive two-dimensional gas chromatography of dichloromethane soluble products from a high sulfur Jordanian oil shale. Talanta 120 (2014) 55–63

[5]. B. Mitrevski, P.J. Marriott. A novel hybrid comprehensive two-dimensional – multi-dimensional gas chromatography for precise, high resolution characterisation of multicomponent samples. Analytical Chemistry, 84 (2012) 4837−4843.

[6]. J.S. Zavahir, Y.  Nolvachai, P.J. Marriott. Molecular spectroscopy – information rich detection for gas chromatography. Trends in Analytical Chemistry. 99 (2018) 47-65

[7]. G.T. Eyres, S. Urban, P.D. Morrison, P.J. Marriott. Application of microscale-preparative multidimensional gas chromatography with nuclear magnetic resonance for identification of pure methylnaphthalenes from crude oils

Journal of Chromatography A, 1215 (2008) 168-176.

 

Short Biography:

Professor Marriott’s career includes PhD in Chemistry (LaTrobe Univ., Melbourne), postdoctoral research (Univ. of Bristol, UK), and academic appointments at the National University of Singapore (Chemistry), RMIT and now Professor of Chemistry at Monash Univ., Melbourne.

His primary research is in GC and MS, specifically in very high resolution comprehensive 2D GC (GC´GC) and multidimensional GC, with MS and other detectors, Research includes fundamental method development and a broad applications base – petrochemicals, essential oils, natural products, pollutants and pesticides, fatty acids, and chiral analysis.

He received an Australian Research Council Discovery Outstanding Researcher Award (2013), and Australian Academy of Science professorial visits in collaboration with the Chinese Academy of Science to China, and to Portugal. He received a World Class University Distinguished Professorship under the Korean National Research Foundation (Chung Ang Univ), and a CNPq Special Researcher Award from Brazil to work with UFRJ and Embrapa on a project on coffee and natural oils.

Professor Marriott has published 388 research papers and book chapters.

Profile Web Link: http://www.monash.edu/science/schools/chemistry/our-people/staff/marriott