新規ナノプラスチック検出法開発に向けた、希土類元素 (REEs) のプラスチックへの吸着特性評価
（令和 6年度）
Adsorption Characteristics of Rare Earth Elements (REEs) on Plastics for Developing a New Nano Plastic Detection Method (REEs as Fingerprints)

研究概要

Although nanoplastics are expected to be almost ubiquitous in various environmental compartments, there is insufficient evidence of their presence due to the difficulty of isolating, collecting, and testing nanoscale plastic particles. This process is difficult, costly, and time-consuming. Consequently, there is an urgent need to find a rapid and economical method to detect nanoplastics in environmental samples.

Rare earth elements (REEs) are considered effective fingerprints for tracking sources and biogeochemical processes because they are sensitive enough to respond to subtle environmental variables. These sensitive correspondences are known as REEs fractionation, which causes different substances in different environments to exhibit distinct REEs patterns. However, it is still largely unknown whether REEs can be used to track nanoplastics (only two journal publications were found in the Web of Science database). There remain two major uncertainties that need to be investigated: (1) the differences in REEs patterns between weathered plastics and other substances in the environment, and (2) whether nanoplastics, due to their large specific surface area, can increase their adsorption capacity for REEs and thus exhibit unique REEs patterns that could be used for tracking nanoplastics.

Therefore, this proposal will conduct adsorption experiments on polypropylene (PP, the most common and easily weathered plastic) in an aquatic environment in two steps:

1. Explore the differences in REEs patterns between weathered macroplastics (PP) and standard sand.
2. Study the differences in REEs patterns among weathered macro, micro, and nanoplastics (PP).

This research will provide recommendations on whether REEs can be used as an effective method for detecting nanoplastics in the environment.

研究の性格

• 主たるもの：基礎科学研究
• 従たるもの：

全体計画

1. Explore the differences in REEs patterns between weathered macroplastics (PP) and standard sand.
2. Study the differences in REEs patterns among weathered macro, micro, and nanoplastics (PP).

今年度の研究概要

1. Explore the differences in REEs patterns between weathered macroplastics (PP) and standard sand.
2. Study the differences in REEs patterns among weathered macro, micro, and nanoplastics (PP).