Professor of Chemistry
Associate Chair for Graduate Education
Ph.D. Iowa State University, 1986
The Synovec group is working in the areas of traditional analytical chemistry and bioanalytical chemistry, centered upon fundamental studies and applications of separation science. Primarily, the group works in the areas of gas chromatography (GC) and liquid chromatography (LC) instrumentation, sensors, analytical methodology, chemical measurement science and multivariate data analysis (chemometrics). Overall, the research group seeks to find a better fundamental understanding of the right balance of chemical separation and mathematical separation required to optimally glean the desired chemical information from analytical separation data. We complement our interest in developing and applying novel instrumentation and chemometrics software with a deep interest in modeling the separation processes based upon theory. Our theoretical modeling has provided fundamental insight and guidance for instrumentation design improvements. Application of our separations technology in many exciting areas such as metabolomics, forensics, petroleum-based fuels, biofuels, and environmental systems are being explored.
In the area of GC, the fields of two-dimensional GC and chemometric data analysis are being integrated. Comprehensive two-dimensional GC instrumentation with time-of flight mass spectrometry detection (GC×GC-TOFMS) has been developed, improved upon, and applied, using two different modulation interfaces: valve-based and thermal-based. The GC×GC-TOFMS instrument provides an information-rich chemical fingerprint for complex samples, and the data is ideally suited for chemometric data analysis. For example, we are pioneering the development of higher order discovery-based software to find up- and down-regulated biomarker metabolites in metabolomics studies. Based upon the locations found in the two dimensional separation space that indicate potential biomarker locations, the GC×GC-TOFMS data at these key locations is further mined to identify and quantify the metabolites of interest. This is accomplished using the chemometric method PARAFAC, a third order data analysis algorithm. Using PARAFAC, analytes of interest are deconvoluted (i.e., mathematically resolved), identified, and quantified, in the presence of unknown interferences, from a single GC×GC-TOFMS data set, under conditions in which only partial chemical selectivity is needed along the three dimensions (the two GC dimensions and the MS dimension). Recently, we have automated the PARAFAC algorithm using a graphical user interface (GUI). This GUI, as well as other chemometric software we have developed, considerably strengthens our ability to provide valuable insight into complex samples analyzed by GC×GC-TOFMS. This research has been currently extended with novel pattern recognition and discovery-based methods for rapid classification and screening applications, e.g., for bioanalytical metabolomics, forensics, petroleum-based fuels, biofuels, and environmental studies. For many of the projects, we also develop and apply novel LC-MS/MS methods to provide a broader understanding of the chemical systems being investigated. For example, in metabolomics studies the metabolites determined by the GC and LC platforms are complementary, with some metabolites determined by both platforms, but many metabolites more readily determined by one approach than the other.
Very recently, the group has also developed a comprehensive three-dimensional gas chromatography instrument (GC×GC×GC), which provides interesting opportunities to study selectivity advantages of three separation dimensions working in concert. Concurrently, work in the area of ultra-high speed GC has been pioneered, with separations on the time scale of a chemical sensor (e.g., separations under a few seconds). This work, in the general area of “GC-on-a-chip,” has involved the study and use of novel single walled carbon nanotube stationary phases within the GC-chip channel structure combined with rapid resistive heating to do rapid temperature programming. For example, GC separations of ten chemical components have been separated in a fraction of one second, and temperature programming rates of 100 °C/second are readily achieved.
"Achieving High Peak Capacity Production for Gas Chromatography and Comprehensive Two-Dimensional Gas Chromatography by Minimizing Off-Column Peak Broadening,” R. B. Wilson, W. C. Siegler, J. C. Hoggard, B. D. Fitz, J. S. Nadeau and R. E. Synovec, J. Chromatogr. A, 2011, 1218, 3130.
"Impurity Profiling of a Chemical Weapon Precursor for Possible Forensic Signatures By Comprehensive Two-Dimensional Gas Chromatography/Mass Spectrometry and Chemometrics,” J. C. Hoggard, J. H. Wahl, R. E. Synovec, G. M. Mong and C. G. Fraga, Anal. Chem., 2010, 82, 689.
"Liquid Chromatography-Tandem Quadrupole Mass Spectrometry and Comprehensive Two-Dimensional Gas Chromatography-Time-of-Flight Mass Spectrometry Measurement of Targeted Metabolites of Methylobacterium extorquens AM1 Grown on Two Different Carbon Sources,” S. Yang, M. Sadilek, R. E. Synovec and M. E. Lidstrom, J. Chromatogr. A, 2009, 1216, 3280.
"Automated Resolution of Non-Target Analyte Signals in GC x GC-TOFMS Data using Parallel Factor Analysis (PARAFAC),” J. C. Hoggard and R. E. Synovec, Anal. Chem., 2008, 80, 6677.
"Toward a Global Analysis of Metabolites in Regulatory Mutants of Yeast,” E. M. Humston, K. M. Dombek, B. P. Tu, E. T. Young and R. E. Synovec, Anal. Bioanal. Chem., 2011, 401, 2387.
“Experimental Study of the Quantitative Precision for Valve-Based Comprehensive Two-Dimensional Gas Chromatography,” W. C. Siegler, B. D. Fitz, J. C. Hoggard and R. E. Synovec, Anal. Chem., 2011, 83, 5190.