- Acting Director, Senior Research Scientist: Ken Riedl, PhD
Ken Riedl, PhD, is an expert in analytical chemistry who develops and applies high-performance liquid chromatography (HPLC)-tandem mass spectrometry to the understanding of dietary food components in disease prevention and control. He operates three HPLC-mass spectrometry platforms, each with unique capabilities for identifying and quantifying phytochemicals and their metabolites. A broad background in food science, biochemistry and analytical chemistry strengthens his role in collaborative, multidisciplinary studies.
Dr. Riedl studied Food Science at the University of Guelph in Ontario, Canada, where he received his bachelor and master’s degrees. He earned his PhD in Biochemistry from Miami University in Oxford, Ohio, investigating polyphenol-protein complexes as antioxidants. As a postdoctoral associate at The Ohio State University, he trained with Dr. Steven Schwartz to develop HPLC-MS skills toward quantitative phytochemical and metabolite analyses.
Mass spectrometry is a desirable detector in analytical chemistry due to its powerful combination of sensitivity and selectivity, which is owing to the often unambiguous characteristic of mass:charge ratio (m/z) of molecular ions and patterns of fragmentation during MS/MS experiments. Primary NPASR equipment includes four ultra-high-pressure liquid chromatography with photodiode array/tandem mass spectrometry systems:
UHPLC/SelexION/QTrap 5500 (Sciex): A hybrid quadrupole ion trap system that typically operates as a triple quadrupole MS but can perform MS/MS/MS (MS3) experiments for enhanced identification and selectivity. The QTrap is also outfitted with the Sciex SelexION differential ion mobility spectrometry device, providing another dimension of separation that enables the Lipidyzer platform and other applications.
UHPLC/SFC/Q-TOF 6550 (Agilent): A quadrupole time-of-flight ion funnel instrument for high-throughput metabolomics as well as discovery lipidomics. This system delivers high mass resolution (up to 40,000) and accurate mass capabilities (1-2 ppm) for identification, as well as best in-class sensitivity and four orders of dynamic range. Super-critical fluid chromatography (SFC) allows for separation of neutral and polar lipids in a single injection, and since SFC behaves like normal phase chromatography, it makes the analysis of very polar compounds that are difficult to retain in reversed phase separations more routine.
UHPLC/Q-TOF 6550 (Agilent): A quadrupole time-of-flight ion funnel instrument that delivers high mass resolution (up to 40,000) and accurate mass capabilities (1-2 ppm) for identification, as well as best in-class sensitivity and four orders of dynamic range. It is used primarily for untargeted metabolomics experiments and identification work.
UHPLC/QqQ 6495 (Agilent): A triple quadrupole with ion funnel optics provides the utmost sensitivity and dynamic range of our instruments allowing for outstanding quantitation. HPLC (Waters): 2 Alliance 2695 systems with 996 and 2996 photodiode arrays (PDA) to quantify small molecules with suitable chromophores. PDA detectors are in-line on all LCMS systems as well to collect UV-vis and MS spectra.