Comparison of commercial solid-phase extraction sorbents for the sample preparation of potato glycoalkaloids

In this study five different commercial sorbents C18, SCX, CN, Certify and Oasis HLB were compared for the solid-phase extraction of potato glycoalkaloids. The recoveries were determined using alpha-solanine, alpha-chaconine and alpha-tomatine, which contained dehydrotomatine as an impurity, as standard compounds. The samples were analysed by reversed-phase liquid chromatography under gradient elution conditions using a Zorbax Rx-C18 column and acetonitrile-25 mM triethylammonium phosphate buffer (pH 3.0) as the mobile phase. The highest recovery (approximately 100%) was achieved with Oasis HLB (60 mg) cartridges. An acetic acid extract of wild Solanum brevidens leaf material was used for the testing of a clean-up procedure. The SCX proved to be the most selective and efficient for removing the undesired components from the leaf extract.