Analysis of microplastics (MP) in environmental samples is an emerging field, which is performed with various methods and instruments based either on spectroscopy or thermoanalytical methods. In general, both approaches result in two different types of data sets that are either mass or particle number related. Depending on detection limits of the respective method and instrumentation the derived polymer composition trends may vary. In this study, we compare the results of hyperspectral Fourier-transform infrared (FTIR) imaging analysis and pyrolysis gas chromatography-mass spectrometry (Py-GC/MS) analysis performed on a set of environmental samples that differ in complexity and degree of microplastic contamination. The measurements were conducted consecutively, and on exactly the same sample. First, the samples were investigated with FTIR using aluminum oxide filters; subsequently, these were crushed, transferred to glass fiber filters, in pyrolysis cups, and measured via Py-GC/MS. After a general data harmonization step, the trends in MP contamination were thoroughly investigated with regard to the respective sample set and the derived polymer compositions. While the overall trends in MP contamination were very similar, differences were observed in the polymer compositions. Furthermore, polymer masses were empirically calculated from FTIR data and compared with the Py-GC/MS results. Here, a most plausible shape-related overestimation of the calculated polymer masses was observed in samples with larger particles and increased particle numbers. Taking into account the different measurement principles of both methods, all results were examined and discussed, and future needs for harmonization of intermethodological results were identified and highlighted.

环境样品中的微塑料 (MP) 分析是一个新兴领域，可使用基于光谱或热分析方法的各种方法和仪器进行分析。一般来说，这两种方法都会产生两种不同类型的数据集，这些数据集要么与质量相关，要么与粒子数相关。根据相应方法和仪器的检测限，得出的聚合物成分趋势可能会有所不同。在本研究中，我们比较了对一组复杂程度和微塑料污染程度不同的环境样品进行高光谱傅里叶变换红外 (FTIR) 成像分析和热解气相色谱-质谱 (Py-GC/MS) 分析的结果。测量是在完全相同的样品上连续进行的。首先，使用氧化铝滤光片通过 FTIR 对样品进行研究；随后，将它们粉碎，转移到热解杯中的玻璃纤维过滤器中，并通过 Py-GC/MS 进行测量。经过一般数据协调步骤后，对相应样品组和衍生聚合物组合物的 MP 污染趋势进行了彻底研究。虽然 MP 污染的总体趋势非常相似，但在聚合物成分中观察到差异。此外，根据 FTIR 数据凭经验计算聚合物质量，并与 Py-GC/MS 结果进行比较。在这里，在具有较大颗粒和增加颗粒数量的样品中观察到了计算出的聚合物质量的最合理的与形状相关的高估。考虑到两种方法的不同测量原理，对所有结果进行了检查和讨论，并确定和强调了未来协调方法间结果的需求。