LaO Nanoparticles: Study of Uptake and Distribution in (Spreng.) Pedersen by LA-ICP-MS and μ-XRF.

The production and use of nanoparticles (NPs) in different fields increased in the last years. However, some NPs have toxicological properties, making these materials potential emerging pollutants. Therefore, it is important to investigate the uptake, transformation, translocation, and deposition of NPs in plants. In this work, laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) and micro X-ray fluorescence (μ-XRF) were used to investigate the uptake and translocation of LaO NPs to stem and leaves of (Spreng.) Pedersen after in vitro cultivation of plants in the presence of 400 mg L of LaO NPs. By using LA-ICP-MS and μ-XRF, image of the spatial distribution of La in the leaves was obtained, where higher concentration of La was observed in the main veins. Differences in the signal profile of La in leaves of plants cultivated in the presence of bulk LaO (b-LaO) and LaO NPs were observed. Sharp peaks of La indicated that NPs were transported to the stems and leaves of plants treated with LaO NPs. Both LA-ICP-MS and μ-XRF techniques have shown to be useful for detecting NPs in plants, but LA-ICP-MS is more sensitive than μ-XRF and allowed better detection and visualization of La distribution in the whole leaf.