摘要

海洋系统和淡水中微米和纳米塑料的污染是一个全球性问题。确定水性环境中的微米和纳米塑料是高度优先考虑的，以充分评估塑料颗粒的风险。尽管已经在各种水生生态系统中检测到微塑料，但纳米塑料的分析仍然是一个未解决的挑战。在此，基于Triton X-45（TX-45）的浊点萃取（CPE）首次被提出用于预浓缩环境水中的痕量纳米塑料。在最佳提取条件下，两种不同组成的纳米塑料，聚苯乙烯（PS）和聚甲基丙烯酸甲酯（PMMA）的富集系数为500，不会影响其原始形态和尺寸。另外，在190℃热处理3小时后，获得的CPE提取物可以进行热解 - 气相色谱/质谱（Py-GC / MS）分析以用于纳米塑料的质量定量。以66.2 nm PS纳米塑料和86.2 nm PMMA纳米塑料为例，该方法具有良好的重现性和高灵敏度，检测限分别为11.5 fM和2.5 fM。通过将优化程序应用于四个真实水样，验证了所提出方法的可行性。在PS纳米塑料的加标水平为88.6fM时，回收率为84.6-96.6％，在PMMA纳米塑料的加标水平为50.4fM时，回收率为76.5-96.6％。因此，这项工作为环境水域中的纳米塑料分析提供了有效的方法。

The contamination of micro- and nanoplastics in marine systems and freshwater is a global issue. Determination of micro- and nanoplastics in the aqueous environment is of high priority to fully assess the risk that plastic particles will pose. Although microplastics have been detected in a variety of aquatic ecosystems, the analysis of nanoplastics remains an unsolved challenge. Herein, for the first time, Triton X-45 (TX-45) based cloud point extraction (CPE) was proposed to preconcentrate trace nanoplastics in environmental waters. Under the optimum extraction conditions, an enrichment factor of 500 was obtained for two types of nanoplastics with different compositions, polystyrene (PS) and polymethyl methacrylate (PMMA), without disturbing their original morphology and sizes. Additionally, following thermal treatment at 190 oC for 3 h, the CPE obtained extract could be submitted to pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) analysis for mass quantification of nanoplastics. Taking 66.2 nm PS nanoplastics and 86.2 nm PMMA nanoplastics as examples, the proposed method showed excellent reproducibility, and high sensitivity with the respective detection limit of 11.5 fM and 2.5 fM. Feasibility of the proposed approach was verified by application of the optimized procedure to four real water samples. Recoveries of 84.6-96.6% at a spiked level of 88.6 fM for PS nanoplastics and 76.5-96.6% at a spiked level of 50.4 fM for PMMA nanoplastics were obtained. Consequently, this work provides an efficient approach for nanoplastic analysis in environmental waters.

https://www.ncbi.nlm.nih.gov/pubmed/30588801