Bec Krzysztof B, Grabska Justyna, Pfeifer Frank, Siesler Heinz W, Huck Christian W
Institute of Analytical Chemistry and Radiochemistry, University of Innsbruck, Innsbruck, Austria.
Department of Physical Chemistry, University Duisburg-Essen, Essen, Germany.
J Hazard Mater. 2024 Dec 5;480:135967. doi: 10.1016/j.jhazmat.2024.135967. Epub 2024 Sep 26.
Contamination by microplastics, a global environmental concern, demands effective monitoring. While current methods focus on characterizing the smallest particles, their low throughput hinders practical assessment. Miniaturized near-infrared (NIR) spectroscopy offers high-throughput capabilities and rapid on-site analysis, potentially filling this gap. However, diverse sensor characteristics result in significant differences among handheld NIR spectrometers. This study characterizes the analytical performance of these instruments for identifying soil microplastics, comparing miniaturized devices MicroNIR 1700ES, NeoSpectra Scanner, microPHAZIR, nanoFTIR-NIR, NIR-S-G1, and SCiO sensor against a reference benchtop instrument, the NIRFlex N-500. Detection of common polymers, ABS, EVAC, HDPE, LDPE, PA6, PMMA, POM, PET, PS, PTFE, and SBR, at low concentrations (0.75 % w/w) was possible without sample preparation. Sensor selection proved crucial; FT instruments N-500 and NeoSpectra Scanner provided the most accurate analysis, while other handheld instruments faced various challenges. Covariance analysis, Principal Component Analysis (PCA), and mid-level data fusion revealed that miniaturized NIR spectrometers can successfully screen microplastics on-site. However, the ability of each sensor to discriminate certain groups of polymers strongly depends on its spectral characteristics. This study demonstrates the importance of sensor selection in the development of portable NIR spectroscopy for environmental monitoring of microplastics.
微塑料污染是一个全球环境问题，需要进行有效监测。虽然目前的方法侧重于对最小颗粒进行表征，但其低通量阻碍了实际评估。小型化近红外（NIR）光谱具有高通量能力和快速现场分析能力，有可能填补这一空白。然而，不同的传感器特性导致手持式NIR光谱仪之间存在显著差异。本研究对这些仪器识别土壤微塑料的分析性能进行了表征，将小型化设备MicroNIR 1700ES、NeoSpectra Scanner、microPHAZIR、nanoFTIR-NIR、NIR-S-G1和SCiO传感器与参考台式仪器NIRFlex N-500进行了比较。无需样品制备即可检测低浓度（0.75% w/w）的常见聚合物，如ABS、EVAC、HDPE、LDPE、PA6、PMMA、POM、PET、PS、PTFE和SBR。事实证明，传感器的选择至关重要；傅里叶变换仪器N-500和NeoSpectra Scanner提供了最准确的分析，而其他手持式仪器则面临各种挑战。协方差分析、主成分分析（PCA）和中级数据融合表明，小型化NIR光谱仪可以成功地现场筛选微塑料。然而，每个传感器区分某些聚合物组的能力在很大程度上取决于其光谱特性。本研究证明了在开发用于微塑料环境监测的便携式NIR光谱技术中，传感器选择的重要性。
