Microplastics are floating in oceans, lakes, rivers and streams. It can be detected in soil, air and animal organisms. It is estimated that many millions of tonnes are released into the environment worldwide every year.
The tiny particles are created when plastic products are carelessly discarded and decomposed by the sun, wind or tides. But they are also present as product additives in toothpaste and cosmetics. The abrasion of car tyres and synthetic fibres that come loose when textiles are worn are also counted as microplastics.
But where and how do microplastics most often end up in the environment? Existing studies on this are based on estimates or extrapolations, which in turn are based on very few exact measurements.
Researchers at BAM have therefore developed a new detection method for microplastics:
Samples from the environment are first heated and the gases produced are then analysed for their components. State-of-the-art measuring instruments - a gas chromatograph and a mass spectrometer - are used. Such a measurement no longer takes one to four weeks, as it used to, but only three hours at the most. And: It can also detect the tiniest microplastic particles - for example, the abrasion from car tyres.
Reference materials for microplastics
The measuring technology is complemented by a BAM development that at first glance seems much more inconspicuous than the state-of-the-art measuring instrument but is just as indispensable: white powder in small, brown glass bottles. These are the world's first reference materials for microplastics.
Reference materials are essential so that laboratories can calibrate their measuring instruments and validate the different methods. Only in this way is it possible to assess whether the instruments are working accurately, and the data supplied can be related to each other in order to derive assessments later.
BAM is now the only institute to offer reference materials for the five most common types of microplastics: Polyethylene and polypropylene, from which bags and food packaging are made, as well as polystyrene, from which transparent fruit trays are made, for example. In addition, polyethylene terephthalate, which is used for beverage bottles, and finally polyamide, a plastic used in materials that are subject to high mechanical stress, such as fishing nets and fishing lines.