Analysis of herbal supplements for selected dietary minerals and trace elements by laser ablation- and solution-based ICPMS

摘要

Concentrations of twelve elements (Mg, Al, Ca, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd) were determined in six herbal supplements, Korean Panax Ginseng (Panax ginseng), Golden Seal (Hydrastis canadensis), Ginger Root (Zingiber officinale), St. John's Wort (Hypericum perforatum), Green Tea (Camellia sinensis) and Valerian Root (Valeriana officinalis), by both laser ablation-inductively coupled plasma mass spectrometry (LA-ICPMS) and conventional closed-vessel digestion solution nebulization-ICPMS (SN-ICPMS). For LA-ICPMS, powder from supplement capsules and leaf reference materials were pressed into pellets, the later being used for calibration and quality assurance. Laser ablation was performed using line scans with a scan rate of 30μmmin ~(-1), a frequency of 20Hz and a spot size of 100μm; ~(13)C served as the internal standard. For LA it was found that low resolution (m/δm≈400) yielded good recoveries for the reference materials and results comparable to SN-ICPMS for most elements, except for Ca, which was better determined in medium resolution (m/δm≈4000). Overall, this study shows that LA-ICPMS can serve as an alternative way for determining the concentration of elements in herbal supplements in a rapid and pragmatic fashion.