Investigation on effects of TiO₂ on cucumber seedlings using ICP-OES and LA-ICP-MS

With the expansion of TiO₂ applications in various fields, TiO₂ inevitably enters the soil, increasing the possibility of plant roots being exposed to high concentrations of TiO₂. Therefore, it is important to study plant growth under TiO₂ exposure conditions. In this study, the combination method of inductively coupled plasma emission spectroscopy (ICP-OES) and laser ablation inductively coupled plasma mass spectroscopy (LA-ICP-MS) was used to evaluate the effect of TiO₂ on the content and distribution of nutrient elements in different parts of cucumber seedlings. The results showed that the low concentrations (50 mg/L, 100 mg/L and 200 mg/L) of TiO₂ had gradually enhanced the growth of cucumber seedlings, while the high concentration (500 mg/L) of TiO₂ had a significant inhibitory effect on the plant. The contents of elements (Ti, K, Ca, Mg, Mn, Fe, Zn, and Cu) in cucumber seedling roots, stems and leaves incubated with 200 mg/L TiO₂ were determined by ICP-OES, and the results showed that the uptake of TiO₂ increased the content of nutrient elements in the plant. High-resolution imaging of Ti, Ca, Mg, Mn, Fe, Zn, and Cu in roots, stems, and leaves using LA-ICP-MS showed that Ti accumulated mainly at the margins of the leaves. Ca, Mg, Mn, Fe, Zn, and Cu in the leaves were mainly concentrated in the main veins and lateral veins. By evaluating the content and distribution of elements in the plant with ICP-OES and LA-ICP-MS, it provides a new idea to study the mechanism of nanoparticles in the plant. It provides a theoretical basis for the correct use of nanomaterials, which is of great significance in promoting the sustainable development of agriculture.