Plastic particles have been found almost everywhere in the environment, in oceans, terrestrial water bodies, sediments and air. The extend of this unwanted contamination is difficult to fully capture. Existing quantification methods focus on the detection of millimeter to micrometer sized plastic particles, while plastic breakdown processes continue to smaller, nanometer sized, particles. For these nanoplastics methods that are inexpensive and can be (semi-) automated for high throughput analysis of dilute nanoplastic particle suspensions, are lacking. ​​​​​​​​​​​​​​Here we combine sensitive fluorescence video microsopy, NileRed staining of plastic particles, and Single Particle Tracking (SPT) to count and size nanoplastics. With this approach we show that particle diameters as low as 40 nm can be extracted, mixing ratios can be recovered, and number concentrations as low as 2·10⁶ particles/ml can be determined. These results indicate that this approach is promising for the quantification of sizes and concentrations of nanoplastics in environmental samples.

在环境，海洋，陆地水体，沉积物和空气中几乎所有地方都发现了塑料颗粒。这种不希望的污染的范围很难完全捕获。现有的量化方法侧重于检测毫米到微米大小的塑料颗粒，而塑料分解过程仍在继续对较小的纳米大小的颗粒进行检测。对于这些纳米塑料，缺乏廉价的方法，并且可以（半）自动化进行稀纳米塑料颗粒悬浮液的高通量分析。这里我们结合了敏感的荧光视频微粒，塑料颗粒的NileRed染色和单颗粒跟踪（SPT）来计算和确定纳米塑料的尺寸。通过这种方法，我们证明可以提取低至40 nm的粒径，可以回收混合比， 可以确定⁶颗粒/ ml。这些结果表明，该方法有望用于定量环境样品中纳米塑料的大小和浓度。