Study of the Mobility of Cerium Oxide Nanoparticles in Soil Using Dynamic Extraction in a Microcolumn and a Rotating Coiled Column

Abstract

Currently, nanomaterials are widely used in various fields of human activity, which inevitably leads to their release into the environment, and soils are one of the main reservoirs for nanoparticles. As nanoparticles can be particularly toxic to living organisms, the development of new approaches to the assessment of their behavior and mobility in soils is an important task. In this paper, the analytical possibilities of the dynamic extraction of CeO₂ nanoparticles in a microcolumn (MC) and a rotating coiled column (RCC) are studied to evaluate the behavior of nanoparticles in soil. Differential and integral elution curves of CeO₂ nanoparticles from the soil were obtained based on the data of eluate analysis by inductively coupled plasma–mass spectrometry. After pumping 100 mL of water through a microcolumn and a rotating coiled column, 0.15 and 1.37 µg of CeO₂ nanoparticles are leached from the soil, respectively, which is 0.2 and 1.6% of the nanoparticles introduced. The ratio of CeO₂ nanoparticles and soil mineral particles is two times higher in the MC eluate. It is found that the rotating coiled column enables the estimation of nanoparticles maximum mobility of nanoparticles in soil because of the minimization of the effect of its structure on their transport. The microcolumn, preserving the soil structure, ensures the estimation of the mobility of nanoparticles in a real soil column most accurately. We also studied the effect of the modification of the surface of CeO₂ nanoparticles with citric acid on their mobility in soil. CeO₂ nanoparticles modified with citric acid have higher mobility in soil compared to unmodified nanoparticles.