Rare earth elements in soils and vegetables

Description

Concentrations of rare earth elements in soils and associated vegetables, including transfer factors, from Istria (Croatia).

Steps to reproduce

Soil samples were air dried, sieved through a 2 mm sieve to remove the gravel fraction, and stored until further analysis. Plants samples were washed with tap and Milli-Q water, and differentiated into different parts (roots, stems, leaves and/or bulbs), air-dried, homogenised in an agate mill and stored until further analysis. For total element analysis, plant sub-samples (~0,07g) were subjected to total digestion in the microwave oven (Multiwave 3000, Anton Paar, Graz, Austria) in a one-step procedure consisting of digestion with a mixture of 6 mL nitric acid (HNO3) and 0.1 mL hydrofluoric acid (HF). Soil sub-samples (~0.05 g) were subjected to total digestion in the microwave oven in a two-step procedure consisting of digestion with a mixture of 4 mL nitric acid (HNO3, 65%, pro analysi, Kemika, Zagreb, Croatia), 1 mL hydrochloric acid (HCl) and 1 mL hydrofluoric acid (HF, 48%, pro analysi, Kemika, Zagreb, Croatia), followed by addition of 6 mL of boric acid (H3BO3, Fluka, Steinheim, Switzerland). Prior to analysis, soil digests were 10-fold diluted, acidified with 2% (v/v) HNO3 (65%, supra pur, Fluka, Steinheim, Switzerland) and In (1 μg/L) as internal standard was added. Plant digests were only acidified with 2% (v/v) HNO3 (65%, supra pur, Fluka, Steinheim, Switzerland) without further dilution, and In (1 μg/L) as internal standard was added. Multielement analysis of prepared samples was performed by an Agilent 8900 triple quadrupole ICP-MS (ICP-QQQ). All samples were analyzed for total concentration of 14 elements (Ce, Dy, Er, Eu, Gd, Ho, La, Lu, Nd, Pr, Sm, Tb, Tm, and Yb). Quality control of the analytical procedure was performed by simultaneous analysis of the blank and certified reference material for soil (NCS DC 77302, China National Analysis Center for Iron and Steel, Beijing, China) and citrus leaves (NCS Certified Reference Material, ZC73018). For each element, the transfer factor (TF) was calculated as the ratio of its concentration in the plant (i.e. plant part) and soil.

Institutions

Categories

Funding

Licence