Automation and subsampling have been proposed as solutions to reduce the time required to quantify and characterize microplastics in samples using spectroscopy. However, there are methodological dilemmas associated with automation that are preventing its widespread implementation including ensuring particles stay adhered to the filter during filter mapping and developing an appropriate subsampling strategy to reduce the time needed for analysis. We provide a solution to the particle adherence issue by applying Skin Tac, a non-polymeric permeable adhesive that allows microplastic particles to adhere to the filter without having their Raman signal masked by the adhesive. We also explore different subsampling strategies to help inform how to take a representative subsample. Based on the particle distributions observed on filters, we determined that assuming a homogenous particle distribution is inappropriate and can lead to over- and under-estimations of extrapolated particle counts. Instead, we provide recommendations for future studies that wish to subsample to increase the throughput of samples for spectroscopic analysis.

中文翻译：

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EXPRESS：迈向微塑料的拉曼自动化：粒子粘附和过滤子采样的开发策略

自动化和二次采样已被提议作为解决方案，以减少使用光谱学对样品中的微塑料进行量化和表征所需的时间。然而，与自动化相关的方法上的困境阻碍了其广泛实施，包括确保粒子在过滤器映射期间保持粘附在过滤器上，以及开发适当的子采样策略以减少分析所需的时间。我们通过应用 Skin Tac 来解决颗粒粘附问题，这是一种非聚合物渗透性粘合剂，可使微塑料颗粒粘附到过滤器上，而不会被粘合剂掩盖其拉曼信号。我们还探索了不同的子抽样策略，以帮助告知如何获取具有代表性的子样本。根据在过滤器上观察到的粒子分布，我们确定假设粒子分布均匀是不合适的，并且可能导致对外推粒子计数的高估和低估。相反，我们为希望子采样以增加光谱分析样品吞吐量的未来研究提供建议。