Basic Information
Abstract Number: 1590-4    
Author Name: R Kenneth Marcus Affiliation: Clemson University
Session Title: Addressing Challenges in Dietary Supplement Analysis
Event Type: Workshop
Event Title: Liquid Chromatography-Particle Beam Electron Ionization Mass Spectrometry Profiling of Botanical Products
Presider(s): Rimmer, Catherine A Start Time: 10:05 AM ( Slot # 6 )
Date: Wednesday, March 14th, 2012 Location: 313
Keywords: Agricultural, Instrumentation, Liquid Chromatography/Mass Spectroscopy, Natural Products

Quarles, Carolyn EClemson University

Abstract Content
The characterization and quantification of active ingredients in botanical extracts is a daunting task. For a given species, the potential target compounds can have dramatically different chemistries, such as flavanoids as well as polyphenols. As such, there must be a diverse arsenal of potential extraction and chemical separation methods that must be affected prior to analysis. Use of some form of liquid chromatography-mass spectrometry (LC-MS) for botanical product analysis would seem to be an obvious choice as great sensitivity and selectivity may be achieved. On the other hand, there are some limitations as to the mode of LC separation that can be performed. The purchase price and need for Ph.D. operators (to use the MS toolbox intelligently) can also be hindrances for some laboratories. Finally, it must be accepted that the quantitative aspects of LC-MS are sometimes lacking.

We describe here the LC-MS characterization of flavanoids extracted from a family of potential NIST reference materials including red clover, soy, and kudzu matrices. A reversed-phase (RP) HPLC is coupled through a particle beam (PB) interface to an electron ionization (EI) source. The interface is highly versatile as wide changes in LC solvent composition (e.g., polarity) do not result in dramatic changes in ionization processes and sensitivity. The EI source produces readily interpreted mass spectra without the need for MS/MS capabilities as required in other LC-MS approaches. Aspects of method development in terms of target species extraction, chromatographic programs, and the ability generate meaningful fragmentation spectra will be described for the flavanoids. The selection and use of an internal standard carried through the entire analytical process will also be presented. Ultimately, it is hoped that this approach can be seen as a characterization tool through the stages of raw materials through to consumer products and metabolites.