| Title: | An on-line normal-phase high performance liquid chromatography method for the rapid detection of radical scavengers in non-polar food matrixes |
| Author(s): | Zhang Q; van der Klift EJ; Janssen HG; van Beek TA; |
| Address: | "Natural Products Chemistry Group, Laboratory of Organic Chemistry, Wageningen University, Dreijenplein 8, 6703 HB Wageningen, The Netherlands" |
| DOI: | 10.1016/j.chroma.2009.08.043 |
| ISSN/ISBN: | 1873-3778 (Electronic) 0021-9673 (Linking) |
| Abstract: | "An on-line method for the rapid pinpointing of radical scavengers in non-polar mixtures like vegetable oils was developed. To avoid problems with dissolving the sample, normal-phase chromatography on bare silica gel was used with mixtures of hexane and methyl tert-butyl ether as the eluent. The high performance liquid chromatography-separated analytes are mixed post-column with a solution of stable free radicals in hexane. Reduced levels of the radical as a result of a reaction with a radical scavenger are detected as negative peaks by an absorbance detector. After investigating a number of different reagents, solvents, concentrations and solution flow rates an optimized instrumental set-up incorporating a superloop for pulse-free delivery of the reagent solution is presented. Both 2,2'-diphenyl-1-picrylhydrazyl (DPPH) and 2,6-di-tert-butyl-alpha-(3,5-di-tert-butyl-4-oxo-2,5-cyclohexadien-1-ylidene)-p-tolyloxy (galvinoxyl) were used as stable free radicals. The method is suitable for both isocratic and gradient HPLC operation. The method has a simple experimental protocol, uses standard instruments and inexpensive and stable reagents, and accepts any hexane-soluble sample. It can also be used for semi-quantitative analysis. The method was applied to several pure, non-polar natural antioxidants, vegetable oils and lipid-soluble rosemary extract. The limits of detection varied from 0.2 to 176 microg/ml, depending on the compound tested" |
| Keywords: | "Antioxidants/*analysis/metabolism Benzhydryl Compounds/chemistry/metabolism Biphenyl Compounds/chemistry/metabolism Chromatography, High Pressure Liquid/*methods Food Analysis/*methods Hexanes/chemistry Mass Spectrometry Oils, Volatile/chemistry Olive Oil;" |
| Notes: | "MedlineZhang, Qiang van der Klift, Elbert J C Janssen, Hans-Gerd van Beek, Teris A eng Research Support, Non-U.S. Gov't Netherlands 2009/09/04 J Chromatogr A. 2009 Oct 23; 1216(43):7268-74. doi: 10.1016/j.chroma.2009.08.043. Epub 2009 Aug 21" |
