Arsenic compounds occurring in ruderal plant communities growing in arsenic contaminated soils

Abstract

Wild growing phytocenosis from three different areas near former gold or silver mines—Kutná Hora, Roudný and Nalžovské Hory (Czech Republic) were investigated for total arsenic and arsenic species concentrations. The most abundant plant families that occurred were Fabaceae, Lamiaceae, Asteraceae, Poaceae and Plantaginaceae. Several plant species such as Achillea millefolium L. (Asteraceae), Anthoxanthum odoratum L. (Poaceae), Plantago lanceolata L. (Plantaginaceae) are widespread and could be found in all of the investigated areas. Total As concentrations in aboveground biomass of plants growing on those three sites were determined by an inductively coupled plasma mass spectrometry (ICPMS) and ranged from 0.02*mgAskg−1 (Stellaria spp.) to 39.30±6.32mgAskg−1 (Daucus carota L.). The concentrations seem to be dependent on both plant species and physico-chemical soil properties. For the arsenic speciation a high performance liquid chromatography (HPLC) online connected with the ICPMS was used. Results have shown that arsenite and arsenate are the prevalent arsenic compounds. Methylarsonic acid (MA), dimethylarsinic acid (DMA), arsenobetaine (AB), arsenocholine (AC), tetramethylarsonium ion (TETRA), and trimethylarsine oxide (TMAO) were identified as minor species. Arsenobetaine was found at significant concentrations in Carex praecox Schreb. (28% of the extractable As amount) and P. lanceolata L. (1.2% of the extractable As amount).