15E-19 |
New developments in natural products analysis |
C. S. YOUNG, Marketing, Alltech Associates, Inc., 2051 Waukegan Rd., Deerfield, IL 60015 and J. W. Walsh, Development, Alltech Associates, Inc. The bulk of HPLC analyses applied to natural products, including nutraceuticals, have been done using reversed phase C18 column chemistries exhibiting traditional moderate- to high-hydrophobicity. Many of the chemical constituents of interest in natural products possess functional groups that benefit from alternative column chemistries capable of enhanced selectivity for polar groups, pi-bonds and aromatic moieties. Additionally, the Evaporative Light Scattering Detector shows great utility for many of these applications and offers the advantages of universal detection. Several natural products mixtures are evaluated using this alternative approach to separation and detection. The goals of this study are two-fold; to show that alternative column chemistries providing enhanced polar selectivity can be beneficial in separating natural product mixtures, and evaporative light scattering detection may be considered a general-purpose detector for a broad range of such samples. Several “nutraceutical” samples are profiled in this paper using mobile phase conditions optimized for the particular sample and analytical column. Comparisons of separations using alkyl-phenyl bonded phases and octadecylsilyl (ODS) bonded phases are presented. Information about sample workup is provided. Throughout, UV and ELS detection are used simultaneously to show comparisons of detection response. Results show that C18 and Phenyl bonded phase columns are complimentary in their ability to resolve a wide range of marker constituents in natural product mixtures. Molecular structure analyses are used to reason predictable plans for optimum separations. Such knowledge is likely to aid analysts in achieving separations of polar natural product components in a minimum timeframe and with superior resolution than may be achieved with traditional approaches using C18 columns.
Session 15E, Nutraceuticals & Functional Foods I
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