Quantifying beryllium concentrations in plant shoots from forest ecosystems using cation-exchange chromatography and quadrupole ICP-MS.

Beryllium (Be) is known to be one of the most toxic elements but at the same time exerts a stimulating effect on plant growth. Despite this contradiction, little is known about the Be metabolism in living organisms, partially because of the low amounts present and because the analysis of Be in plants by ICP-MS remains challenging. The challenges arise from the complex organic matrix, the low abundance of Be relative to the other plant essential elements, and the matrix effects resulting thereof in the plasma. To address these challenges, we developed and evaluated a new method for Be concentration analysis in plant material. Key is the quantitative separation of Be from the other matrix elements by cation-exchange chromatography. The new method was verified by processing seven reference materials representing different plant matrices yielding a long-term reproducibility of 16% (RSD). Applying the method, Be concentrations in tree, shrub, bush, and grass samples grown in non-polluted ecosystems from four temperate forests and a tropical rainforest were measured. The Be concentrations in different plant organs range from 0.01 to 63 ng/g that suggest a natural baseline for Be concentrations of 52 ng/g (95 percentile of non-woody tissue) that may serve as bioindicator for Be pollution in the environment. Comparison of Be concentrations in plants with the soil's biologically available fraction revealed that Be is discriminated from uptake into shoots and thus can be considered as non-essential.