Novel metallomic profiling and non-carcinogenic risk assessment of botanical ingredients for use in herbal, phytopharmaceutical and dietary products using HR-ICP-SFMS

Abstract

Knowledge of element concentrations in botanical extracts is relevant to assure consumer protection given the increased interest in plant-based ingredients. This study demonstrates successful multi-element investigations in order to address the lack of comprehensive profiling data for botanical extracts, while reporting for the first time the metallomic profile(s) of arnica, bush vetch, sweet cicely, yellow rattle, bogbean, rock-tea and tufted catchfly. Key element compositions were quantified using a validated HR-ICP-SFMS method (µg kg−1) and were found highly variable between the different plants: Lithium (18–3964); Beryllium (3–121); Molybdenum (75–4505); Cadmium (5–325); Tin (6–165); Barium (747–4646); Platinum (2–33); Mercury (5–30); Thallium (3–91); Lead (12–4248); Bismuth (2–30); Titanium (131–5827); Vanadium (15–1758); Chromium (100–4534); Cobalt (21–652); Nickel (230–6060) and Copper (1910–6340). Compendial permissible limits were not exceeded. Overall, no evidence of a health risk to consumers could be determined from consumption of the investigated plants at reasonable intake rates. Mathematical risk modelling (EDI, CDI, HQ, HI) estimated levels above safe oral thresholds only for Cd (16%) and Pb (8%) from higher intakes of the respective plant-derived material. Following high consumption of certain plants, 42% of the samples were categorised as potentially unsafe due to cumulative exposure to Cu, Cd, Hg and Pb. PCA suggested a potential influence of post-harvest processing on Cr, Ti and V levels in commercially-acquired plant material compared to wild-collected and farm-grown plants. Moreover, a strong correlation was observed between Pb-Bi, Be-V, Bi-Sn, and Tl-Mo occurrence. This study may support future research by providing both robust methodology and accompanying reference profile(s) suitable for the quality evaluation of essential elements and/or metal contaminants in botanical ingredients.