Micro- and nanoplastics (MNPs) are increasingly found in all realms of the world, including water and soil. Now, there is growing concern over this type of pollution in the air. Many well-established techniques exist for detecting particulate matter (PM) in the air. They are low-cost and handheld, and some of them even allow direct detection from the air. While various MNP detection methods have been demonstrated, airborne MNP detection methods depend on expensive laboratory instruments. This review paper examines the current analytic methods used to identify PM and MNP and discusses their similarities and differences. PM can be detected directly from the air primarily via light scattering, while direct air detection of MNP has not been demonstrated. Sampling steps allow both PM and MNP to be detected from the air. Since PM detection does not require the type identification of materials, mass detection has been utilized, including gravimetric and microbalance methods. Simple optical detection based on absorbance or reflectance and electrical current measurements have also been used for PM detection. However, MNP detection does require type identification, including plastic vs non-plastic or the type of plastic, requiring more sophisticated methods, including spectroscopic and thermal analyses. Microscopic identification has been utilized for both PM and MNP detection since it can identify the size, morphology, autofluorescence, and spectroscopic properties. Machine learning algorithms can also analyze the microscopic images and spectra to identify the type of PM and MNP. While microscopic identification previously required a bulky benchtop microscope, a portable or even handheld microscope has become available, allowing it to detect MNPs in a portable, low-cost manner.

中文翻译：

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现有颗粒物和微纳米塑料检测分析方法的比较

微塑料和纳米塑料 (MNP) 越来越多地出现在世界各个领域，包括水和土壤。现在，人们越来越担心空气中的此类污染。有许多成熟的技术可用于检测空气中的颗粒物 (PM)。它们成本低廉、手持式，其中一些甚至允许从空中直接检测。虽然已经论证了各种 MNP 检测方法，但机载 MNP 检测方法依赖于昂贵的实验室仪器。本文探讨了当前用于识别 PM 和 MNP 的分析方法，并讨论了它们的异同。主要通过光散射可以直接从空气中检测 PM，而直接空气检测 MNP 尚未得到证实。采样步骤可以从空气中检测到 PM 和 MNP。由于PM检测不需要材料的类型识别，因此采用了质量检测，包括重量分析和微量天平方法。基于吸光度或反射率以及电流测量的简单光学检测也已用于 PM 检测。然而，MNP 检测确实需要类型识别，包括塑料与非塑料或塑料类型，需要更复杂的方法，包括光谱和热分析。显微识别已用于 PM 和 MNP 检测，因为它可以识别尺寸、形态、自发荧光和光谱特性。机器学习算法还可以分析显微图像和光谱来识别 PM 和 MNP 的类型。虽然显微识别以前需要笨重的台式显微镜，但便携式甚至手持式显微镜已经可用，使其能够以便携式、低成本的方式检测 MNP。