| Abstract [eng] |
Swainsonine, an indolizidine alkaloid, is found in some Astragalus, Oxytropis, and Swainsona species of the Leguminosae family growing throughout the world. Consumption of swainsonine containing plants by grazing animals leads to a chronic neurologic disease characterized by weight loss, depression, and death. Rapid, sensitive and accurate analytical methods are therefore needed to detect and to determine swainsonine in plants. In this master thesis hydrophilic interaction chromatography (HILIC) technique combined with tandem mass spectrometry was developed and validated for the rapid and sensitive quantification of swainsonine. Developed technique was employed for the determination of swainsonine in milkvetch (Astragalus sp.) growing in Lithuania. Obtained results showed that in comparison to conventional reversed-phase separation mode, HILIC technique provided significantly better retentivity for swainsonine. HILIC separation was performed on an Acquity UPLC BEH HILIC (2.1×100 mm, 1.7 μm) column using a mixture of acetonitrile and water (90:10, v/v) with 10 mmol/L formic acid as the mobile phase. The calibration curve showed good linearity over the concentration range 0.005-0.75 mg/L corresponding to 0.75-112.5 μg/g in dry matter (DM) of the original plant material. The estimated limit of quantification for the method was 5.0 μg/L (0.75 μg/g DM). The optimized method was applied to determine swainsonine in two milkvetch species (Astragalus cicer and Astragalus glycyphyllos) growing in Lithuania. The highest swainsonine concentration (6.72 μg/g DM) was found in the leaves of the plant. It was determined that the amount of swainsonine in the aerial part of milkvetch increases with its stage of growth. |
