Selectively and efficiently capturing trace titanium dioxide nanoparticles (TiO₂NPs) in environmental waters is a prerequisite for their determination to understand their occurrence, behavior and effects in the environment. Herein, we report the determination of TiO₂NPs by using magnetic microextraction with phosphorylated Fe₃O₄ as a selective adsorbent, followed by inductively coupled plasma mass spectrometry (ICP-MS) detection. The phosphorylated Fe₃O₄ was prepared by modifying phosphoric acid groups on the surface of synthesized Fe₃O₄, added into the water samples to selectively adsorb and agglomerate with TiO₂NPs, and collected using a permanent magnet. Under the optimized extraction parameters, the factors including sizes and concentrations of TiO₂NPs, volumes of water samples, and dissolved organic matter (0–30 mg C L⁻¹) showed little effects on the extraction process. The feasibility of the method was further validated by the analysis of natural water samples, with spiked recoveries of 81.9–99.1% and an extremely low detection limit of 0.4 ng L⁻¹. This method is capable of accurately detecting and quantifying the concentration of trace TiO₂NPs in aquatic systems, which contributes to monitoring the fate of TiO₂NPs in the environment and assessing their hazards.

中文翻译：

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磷酸化四氧化三铁高选择性捕获并有效浓缩环境水中的痕量二氧化钛纳米颗粒

选择性、高效地捕获环境水中的痕量二氧化钛纳米粒子（TiO ₂ NPs）是测定它们以了解其在环境中的发生、行为和影响的先决条件。在此，我们报道了通过使用磷酸化Fe ₃ O ₄作为选择性吸附剂的磁微萃取，然后进行电感耦合等离子体质谱（ICP-MS）检测来测定TiO _{2 NP。通过修饰合成的Fe 3} O ₄表面的磷酸基团制备磷酸化的Fe ₃ O _{4 ，将其添加到水样中与TiO 2} NP选择性吸附并团聚，并使用永磁体收集。在优化的萃取参数下，TiO ₂ NPs的尺寸和浓度、水样的体积以及溶解的有机物(0–30 mg CL ^-1 )等因素对萃取过程影响很小。通过天然水样的分析进一步验证了该方法的可行性，加标回收率为81.9%~99.1%，检出限极低，为0.4 ng L ^-1。该方法能够准确检测和定量水生系统中痕量TiO ₂ NPs的浓度，有助于监测TiO ₂ NPs在环境中的归宿并评估其危害。