Abstract:
For a plastic syringe, a stopper at the end of plunger is usually made of polydimethylsiloxane (PDMS, and co-ingredients). To reduce friction and prevent leakage between the stopper and barrel, short chain polymer of liquid PDMS is also used as lubricant. Consequently, an injection process can release solid PDMS debris from the stopper and barrel, and liquid PDMS droplets from the lubricant, both of which are confirmed herein as solid and liquid micro(nano)plastics. From molecular spectrum perspective to directly visualise those micro(nano)plastics, Raman imaging was employed to analyse hundreds-to-thousands of spectra (hyper spectrum or hyperspectral matrix) and significantly enhance signal-to-noise ratio. From morphology perspective to provide high resolution of image, scanning electron microscopy (SEM) was engaged to cross-check with Raman images and increase assignment / quantification certainty. The weak Raman imaging signal of nanoplastics was extracted using image deconvolution algorithm to remove the background noise and average the signal variation. To increase the result\'s representativeness and avoid quantification bias, multiple syringes were tested and multiple areas were randomly scanned toward statistical results. It was estimated that thousands of microplastics and millions of nanoplastics of solid/liquid PDMS might be injected when using a plastic syringe of 1 mL. Overall, Raman imaging (along with algorithm and SEM) can be helpful for further research on micro(nano)plastics, and it should be cautious to use plastic syringe due to the increasing concern on the emerging contamination of not only solid but also liquid micro(nano)plastics.
摘要:
对于塑料注射器,柱塞末端的塞子通常由聚二甲基硅氧烷(PDMS,和共同成分)。为了减少摩擦并防止塞子和桶之间的泄漏,液体PDMS的短链聚合物也用作润滑剂。因此,注射过程可以从塞子和桶中释放固体PDMS碎片,和来自润滑剂的液体PDMS液滴,这两者在本文中被确认为固体和液体微(纳米)塑料。从分子光谱的角度直接可视化那些微(纳米)塑料,拉曼成像用于分析数百至数千个光谱(超光谱或高光谱矩阵)并显着增强信噪比。从形态学的角度提供高分辨率的图像,扫描电子显微镜(SEM)从事与拉曼图像的交叉检查和增加分配/量化的确定性。利用图像反卷积算法提取纳米塑料的微弱拉曼成像信号,去除背景噪声,并对信号变化进行平均。为了增加结果的代表性,避免量化偏差,对多个注射器进行了测试,并对多个区域进行了随机扫描,以获得统计结果.据估计,当使用ImL的塑料注射器时,可以注射数千个微塑料和数百万个固体/液体PDMS的纳米塑料。总的来说,拉曼成像(连同算法和SEM)有助于微(纳米)塑料的进一步研究,由于人们越来越关注不仅是固体而且是液体微(纳米)塑料的污染,因此使用塑料注射器应该谨慎。