Fast Quantitative Detection of Microplastics Using TED-GC/MS, an Innovative Thermoanalytical Method

Analyzing Microplastics in the Environment: Striving to Better Assess Occurrence, Fate and Effects (Session 2)
Oral Presentation

Prepared by P. Eisentraut1, U. Braun2, K. Altmann1
1 - Bundesanstalt für Materialforschung und -prüfung (BAM), Unter den Eichen 87, Berlin, Berlin, 12205, Germany
2 - Umweltbundesamt, Schichauweg 58, Berlin, Berlin, 12307, Germany


Contact Information: paul.eisentraut@bam.de; 00493081044304

ABSTRACT

Microplastic (MP) particles in a size range of 1 µm to 1 mm, derived from thermoplastic and elastomeric materials, have been found in all compartments of the world [1], even in the most remote areas.
In order to identify possible effects on the environment and initiate regulatory and technical measures, sources, paths and sinks must be clearly identified and material flow balances recorded. This requires fast analytical methods with a high throughput in terms of sampling, sample preparation and detection. As a recently established, fully automated method for microplastic detection, thermal extraction and desorption gas chromatography coupled with mass spectrometry (TED-GC-MS) meets most of these requirements [2]. The functional principle of the method is the detection of thermal decomposition products that are specific for the polymers to be examined. The method is suitable for the quantitative recording of the mass of all relevant thermoplastics as well as an elastomer that can be used as a marker substance for tire wear which in term is suspected to be a major contributor to the overall MP emissions to the environment. The main features of this method are good reproducibility due to the use of an internal standard, sample sizes of up to 100 mg for representative results, low maintenance requirements due to the indirect coupling of the sensitive GC/MS equipment with the sturdy TGA pyrolysis module and fast measurements with low detection limits. In contrast to microscopic-spectroscopic methods, only minor or even no sample pretreatment is necessary, the method is faster, and the result is determined in dimensions of mass content or mass concentration, as commonly preferred by regulators [3].
Recently, BAM developed MP reference materials which can be used to validate and improve analytical methods and protocols for the detection of MP.

[1] J. Gasperi, Current Opinion in Environmental Science & Health 2018, 1, 1-5.
[2] E. Dümichen, Chemosphere 2017, 174, 572-584.
[3] P. Eisentraut, Environmental science & technology letters 2018, 5, 608-316.